Companion Planting Reference Chart

New England Vegetable Gardens — Workshop and Consulting Reference

Companion Planting by Crop

Crop	Pest Deterrence	Growth & Yield	Keep Away
Solanaceae — Tomatoes, Peppers, Eggplant
Tomatoes	Basil — deters hornworm, aphids, spider mites French Marigolds — deters nematodes, whitefly Onions / Garlic — deters aphids, soft-body insects	Basil — improves flavor in close proximity Carrots — loosens soil around roots	Fennel — allelopathic, stunts growth Brassicas — compete for heavy nutrients Corn — shares earworm pest pressure
Peppers	Basil — deters aphids, spider mites French Marigolds — deters nematodes Onions / Garlic — deters aphids	Carrots — loosens soil, no root competition Spinach — living mulch, retains moisture	Fennel — allelopathic Brassicas — compete for nutrients
Eggplant	Tarragon — broadly deters insects French Marigolds — deters nematodes	Green Beans — fix nitrogen, improve yield	Fennel — allelopathic Corn — shares Colorado potato beetle
Brassicas — Cabbage, Broccoli, Kale, Kohlrabi, Cauliflower, Brussels Sprouts
Brassicas (all)	Onions / Garlic — deters aphids, cabbage loopers Celery — repels cabbage white butterfly Thyme — deters cabbage worms Hyssop — deters cabbage moths Mint — repels aphids, flea beetles (contain in pot)		Tomatoes — share fungal disease, compete Strawberries — mutual growth inhibition Pole Beans — compete for resources Grapes — allelopathic to brassicas
Cucurbits — Cucumber, Squash, Zucchini, Melon, Pumpkin
Cucumbers	Nasturtiums — repels cucumber beetles, aphids Radishes — deters cucumber beetles	Sunflowers — wind protection, attract pollinators Corn — structural support, wind break	Sage — inhibits cucumber growth Potatoes — share disease and pests Fennel — allelopathic
Squash & Zucchini	French Marigolds — deters nematodes Borage — deters squash pests	Corn — Three Sisters, structural support Beans — Three Sisters, fix nitrogen for squash	Potatoes — share pests Fennel — allelopathic
Root Crops — Carrots, Beets, Potatoes
Carrots & Beets	Onions — deters carrot fly by scent masking (mutual relationship) Garlic — deters carrot fly, aphids Leeks — deters carrot fly Rosemary — confuses carrot fly with aromatics Sage — confuses carrot fly Chives — deters aphids Catnip — deters flea beetles (beets especially)	Lettuce — shallow roots, no competition with either crop Radishes — loosen soil, mark slow-germinating rows Chamomile — improves growth and flavor of both crops Onions — good row companions for beets specifically	Dill (mature) — inhibits carrot growth Parsnips — share carrot fly pressure Fennel — allelopathic Pole beans — inhibit beet growth
Potatoes	Horseradish — deters Colorado potato beetle at corners French Marigolds — deters nematodes Coriander — repels aphids, spider mites	Beans — fix nitrogen, improve yield Chamomile — improves growth	Tomatoes — share late blight Cucumbers — share pests Raspberries — share blight Sunflowers — inhibit potato growth Fennel — allelopathic
Corn
Corn		Beans — Three Sisters, fix nitrogen for corn Squash — Three Sisters, ground cover suppresses weeds Cucumbers — use corn as windbreak	Tomatoes — share earworm pressure Eggplant — shares pests
Lettuce & Salad Greens
Lettuce & Greens	Chives — deters aphids Garlic — deters aphids	Carrots — deep roots, no competition Radishes — loosen soil, mark rows Tall crops — provide shade, delays bolting in heat	Celery — competes for resources Parsley — can inhibit in close proximity

Trap Cropping. Nasturtiums function as a universal trap crop throughout the garden. Plant at bed edges and as perimeter rows. Aphids, caterpillars, cucumber beetles, and whitefly preferentially attack nasturtiums — concentrating pests for hand removal or beneficial predation. Edible flowers and leaves are a bonus.

Beneficial Insect Habitat. Plant dill, borage, parsley, and chamomile throughout the garden and allow them to flower. These attract braconid wasps, lacewings, hoverflies, and parasitic wasps that control aphids, caterpillars, and other pests across all crops simultaneously. Beneficial insect attraction is a garden-wide practice, not a crop-specific one.

Key Antagonistic Relationships

Plant / Pairing	Incompatible With	Why
Fennel	Almost all vegetables	Broadly allelopathic — root and volatile compounds inhibit most vegetables. Plant in isolation or containers away from the vegetable garden.
Garlic, Onions & Chives	Beans, peas, asparagus	Sulfur compounds that make alliums valuable pest deterrents actively inhibit legume growth, interfere with nitrogen fixation, and mutually inhibit asparagus. Keep all alliums away from these crops.
Tomatoes + Potatoes	Each other	Share late blight (Phytophthora infestans). Separating them limits disease transmission and reduces inoculum buildup.
Brassicas + Tomatoes	Each other	Both heavy feeders competing for nutrients. Share fungal disease pressure. Do not plant adjacent or rotate into the same bed consecutively.
Mature Dill	Tomatoes, carrots, peppers	Young dill is a beneficial companion. Once mature and flowering, dill inhibits growth of tomatoes, carrots, and peppers.
Sage + Basil	Each other	Mutual inhibition when planted in direct proximity. Both are useful companions for other crops but should not be adjacent to each other.

Legumes — Nitrogen Fixation and Rotation

Legume	Best Rotation Partners	Proximity Companions	Critical Notes
Bush & Pole Beans	Follow with brassicas, corn, or squash — heavy feeders benefit from nitrogen left behind	Summer savory — deters bean beetles Marigolds — deters Mexican bean beetle Corn — Three Sisters Potatoes — mutual benefit	Keep away from all alliums — inhibits growth and nitrogen fixation. Do not fertilize with nitrogen.
Peas	Follow with corn, brassicas, or squash	Mint — deters aphids (contained) Radishes — deter aphids Carrots — good row companions Nasturtiums — trap aphids	Same allium restriction as beans. Cool season crop. Do not fertilize with nitrogen.
Cover Crop Legumes (field peas, vetch, clover)	Plant before any heavy nitrogen feeder — tomatoes, corn, brassicas, squash	Not applicable — grown as cover, terminated before cash crop	Inoculate with rhizobia if legumes not previously grown in that bed. Most valuable nitrogen contribution is through rotation, not proximity.

Rhizobia inoculant should be applied to legume seed at planting if that crop family has not been grown in that bed previously.

Crop Rotation by Plant Family

Rotate by plant family, not by individual crop. Moving tomatoes but planting peppers in the same bed keeps the same solanaceae pest and disease pressure alive. The family is the unit of rotation.

Vegetable Families — Know What Follows What

Family	Common Members	Notes
Solanaceae (Nightshade)	Tomatoes, peppers, eggplant, potatoes	Heavy feeders. Share late blight, early blight, Colorado potato beetle, hornworm. Never follow one solanaceae with another. Tomatoes and potatoes share blight — separate in rotation and in the garden.
Brassicaceae (Cabbage family)	Cabbage, broccoli, kale, cauliflower, Brussels sprouts, kohlrabi, radish, turnip, arugula	Heavy feeders. Share club root, cabbage worms, flea beetles. Club root spores persist 20+ years — a 4-year rotation minimum, longer if club root is confirmed.
Cucurbitaceae (Squash family)	Cucumber, squash, zucchini, melon, pumpkin	Heavy feeders. Share cucumber beetle, powdery mildew, bacterial wilt. Rotate out of any bed with confirmed bacterial wilt history.
Alliaceae (Onion family)	Garlic, onions, leeks, chives, shallots	Moderate feeders. Share allium leaf miner, white rot. White rot persists in soil for decades — serious rotation discipline required if confirmed.
Apiaceae (Carrot family)	Carrots, parsnips, celery, parsley, dill, fennel	Light feeders. Share carrot fly. Do not follow with each other — parsnips and carrots share pest pressure directly.
Fabaceae (Legume family)	Beans, peas, clover, vetch	Nitrogen fixers — light feeders, leave nitrogen behind. Always valuable preceding heavy feeders in rotation. See legumes section above.
Chenopodiaceae (Beet family)	Beets, spinach, chard, quinoa	Light to moderate feeders. Few serious shared pest issues. Flexible rotation partners — follow or precede most families without concern.
Asteraceae (Daisy family)	Lettuce, chicory, artichoke, sunflower	Light feeders. Few serious soil-borne issues. Good rotation flexibility — useful gap fillers between heavier families.
Poaceae (Grass family)	Corn, wheat (cover crop)	Heavy nitrogen feeder. Plant after legumes whenever possible. Corn earworm can build if corn follows corn — rotate annually.

Simple Four-Year Rotation Framework

A practical starting point for a four-bed or four-zone garden. Adapt to what you actually grow — the principle matters more than the exact sequence.

Bed	Year 1	Year 2	Year 3	Year 4
Bed 1	Heavy feeders (Solanaceae, Cucurbits, Corn)	Light feeders (Roots, Greens, Alliums)	Legumes (Beans, Peas — fix nitrogen)	Brassicas (benefit from prior nitrogen)
Bed 2	Light feeders (Roots, Greens, Alliums)	Legumes (Beans, Peas)	Brassicas	Heavy feeders (Solanaceae, Cucurbits, Corn)
Bed 3	Legumes (Beans, Peas)	Brassicas	Heavy feeders (Solanaceae, Cucurbits, Corn)	Light feeders (Roots, Greens, Alliums)
Bed 4	Brassicas	Heavy feeders (Solanaceae, Cucurbits, Corn)	Light feeders (Roots, Greens, Alliums)	Legumes (Beans, Peas)

Key rules regardless of rotation scheme:

Minimum 3 years before returning a family to the same bed — 4 years preferred for solanaceae and brassicas
Never follow solanaceae with solanaceae — this includes tomatoes, peppers, eggplant, AND potatoes
Legumes before heavy feeders whenever possible — free nitrogen
Never leave a bed bare — cover crop or mulch immediately when a crop clears
Keep records — a simple sketch of what grew where each season is the most valuable rotation planning tool
Any rotation is better than none — imperfect rotation still breaks pest and disease cycles meaningfully

Soil Amendment Reference Chart

Common Organic Amendments — Workshop and Consulting Reference

Amendment	NPK (approx)	Source	Release Rate	Primary Benefit	Best Application	Rate per 100 sq ft	Cautions / Notes
Composts & Biologicals
Finished Compost	Varies ~1-1-1	Plant/animal matter	Slow — ongoing	Soil biology, organic matter, structure, moisture retention	2–4" top dress spring and fall. Base of all bed building.	1–2 cubic feet	Quality varies enormously by source. Hot-composted preferred. Never use uncomposted material directly in root zone.
Worm Castings	~1-0-0 + trace	Earthworm digestion	Slow — gentle	Concentrated biology, microbial diversity, no burn risk	Transplant hole (¼ cup), seed starting mix, top dress	5–10 lbs	Most consistent biological amendment available. Cannot over-apply. Expensive at scale — prioritize for transplant holes and seedlings.
Mycorrhizal Inoculant	0-0-0	Fungal spores	Immediate colonization	Extends root surface area, phosphorus and water access, transplant establishment	Direct root contact at transplant — sprinkle on roots or in hole	Per label	Must contact roots directly to colonize. High soil phosphorus suppresses colonization — avoid excess bone meal at same application. Not a fertilizer — a biological relationship.
Compost Tea (aerated)	Variable	Finished compost	Immediate — liquid	Rapid biological inoculation of soil and foliar surface	Drench transplants or established beds. Foliar spray for disease suppression.	1–2 gal per 100 sq ft	Must be actively aerated 24–36 hours before use. Apply immediately — biology dies within hours of brewing. Do not use anaerobic (non-aerated) tea.
Nitrogen Sources
Blood Meal	12-0-0	Dried animal blood	Fast — 2–6 weeks	Quick nitrogen boost for deficient or heavy-feeding crops	Top dress mid-season when nitrogen deficiency appears. Not at transplant.	1–3 lbs	Fast release can burn if over-applied. Suppresses mycorrhizal colonization at transplant — use as mid-season top dress instead. Strong odor may attract animals.
Feather Meal	12-0-0	Poultry feathers	Medium — 2–4 months	Sustained nitrogen release. Slower than blood meal, longer feeding window.	Pre-plant incorporation or transplant hole for heavy feeders (tomatoes, corn, squash)	2–4 lbs	More predictable than blood meal. Good for long-season crops needing sustained nitrogen. Less burn risk than blood meal.
Fish Meal	10-6-2	Dried fish	Medium — 4–8 weeks	Balanced nitrogen with phosphorus and potassium. Good all-purpose feeding.	Transplant hole or pre-plant incorporation for most vegetable crops	2–4 lbs	Strong odor. May attract wildlife — work into soil surface. Good alternative to blood meal with added phosphorus and potassium.
Alfalfa Meal	3-1-2	Dried alfalfa	Medium — 4–6 weeks	Balanced mild nutrition, triacontanol (natural growth stimulant), soil biology feeding	Broadcast and incorporate. Good for general bed fertility building.	4–6 lbs	One of the most cost-effective and balanced mild amendments. Triacontanol content stimulates root and shoot growth. Good base amendment for any bed.
Phosphorus, Calcium & Magnesium Sources
Bone Meal	3-15-0	Ground animal bones	Slow — 4+ months	Phosphorus for root development. Calcium for cell structure.	Phosphorus-deficient soils. Root crops (potato, carrot). Use sparingly.	2–4 lbs	Calcium and phosphorus are often already adequate in managed soils. Excess phosphorus suppresses mycorrhizal activity — test soil before applying broadly. Reserve for documented deficiency or root crops.
Kelp Meal	1-0-2 + trace	Dried seaweed	Slow — ongoing	Broad trace minerals, natural plant vitamins (B1), rooting support, soil conditioning	Transplant hole (1 tsp), pre-plant incorporation, compost activator	1–2 lbs	Low NPK — value is in trace minerals and plant hormones, not macronutrients. One of the best low-rate universal amendments. Cannot harm with normal application rates.
Gypsum	0-0-0 +Ca+S	Calcium sulfate	Medium — season	Calcium without pH change. Sulfur for alliums and brassicas. Breaks clay compaction.	Broadcast on heavy clay soils. Allium and brassica beds for sulfur.	5–10 lbs	Does not change soil pH — unlike lime. Good calcium source when pH is already adequate. Sulfur content improves flavor of alliums.
Dolomitic Lime	0-0-0 +Ca+Mg	Mined limestone	Slow — season+	Calcium and magnesium together. Raises soil pH. Corrects acid soils.	Broadcast on acid soils needing both pH adjustment and Ca/Mg. Test pH first.	5–10 lbs	Raises soil pH — do not use if pH already adequate or alkaline. Test before applying. The organic source of both calcium and magnesium simultaneously. Most useful in NH's naturally acid soils.
Epsom Salt	0-0-0 +Mg+S	Mined magnesium sulfate	Fast — soluble	Corrects magnesium deficiency. Sulfur for alliums and brassicas.	Foliar spray (1 tbsp/gal) or soil drench when magnesium deficiency confirmed — interveinal yellowing on OLD leaves.	1 tbsp/gal foliar	Widely over-applied. Does NOT correct blossom end rot — BER is calcium delivery failure caused by inconsistent watering. Excess magnesium competes with calcium uptake. Confirm deficiency before applying.
Potassium Sources
Greensand	0-0-3 + trace	Glauconite mineral	Very slow — years	Long-term potassium. Trace minerals. Soil structure improvement.	Incorporate into new bed construction. Long-term soil building.	5–10 lbs	Very slow release — not a quick fix. Most valuable as a long-term soil building investment. Works well in combination with faster-release amendments.
Wood Ash	0-1-3	Hardwood ash	Fast — soluble	Potassium and calcium. Raises soil pH. Good for acid soils.	Light broadcast on acid soils. Around fruiting crops in mid-season.	5 lbs max	Raises soil pH significantly — do not use on already alkaline soils or near acid-loving plants. Do not use fresh — leach heavy metals. Hardwood only, not treated wood.
Sul-Po-Mag (Langbeinite)	0-0-22 +Mg+S	Mined mineral	Medium	Potassium, magnesium, and sulfur without changing pH.	Potassium-deficient soils. Tomatoes and peppers (magnesium uptake for fruiting).	2–4 lbs	One of the few sources delivering K, Mg, and S simultaneously without pH effect. Useful when magnesium deficiency appears (yellowing between leaf veins on older leaves).
Specialty Amendments
Neem Seed Meal	6-1-2	Neem seed pressing	Medium — 4–8 weeks	Pest suppression (soil insects, nematodes). Fungal disease deterrence. Moderate nitrogen.	Transplant hole for brassicas and other pest-susceptible crops. Incorporate pre-plant.	2–4 lbs	Biofumigant properties from azadirachtin compounds. Most effective when incorporated into soil. Good addition to transplant mix for brassicas and crops with known pest pressure.
Azomite	0-0-0 + 70 trace	Volcanic mineral	Very slow — years	Broad spectrum trace mineral remineralization. Micronutrient diversity.	New bed construction. Annual small top dress.	1–2 lbs	Not a fertilizer — a trace mineral source. Most valuable in depleted or heavily cropped soils. Low cost, long-lasting. Good addition to any new bed build.
Biochar	0-0-0	Charred biomass	Permanent	Long-term water and nutrient retention. Habitat for soil biology. Permanent soil structure improvement.	Incorporate into new bed construction. Charge with compost or nutrients before use.	2–5 lbs	Must be charged (mixed with compost or fertilizer) before use — raw biochar can initially bind nutrients away from plants. Once charged, provides permanent benefits. One-time investment.

SMALL FARM Transplant Amendment Recipe

A consistent, repeatable recipe for every transplant. Built around soil biology first, targeted nutrition second. Variations by plant family listed below.

Base Recipe — Every Transplant, Every Family

Amendment	Amount per Hole	Purpose	Notes
Mycorrhizal Inoculant	Per label — direct root contact	Establishes fungal partnership immediately. Extends root reach for phosphorus and water.	Must contact roots directly. Avoid high-phosphorus amendments at same application.
Worm Castings	¼ cup	Concentrated biology and gentle nutrition. No burn risk.	Most reliable biological amendment. Cannot over-apply at this rate.
Kelp Meal	1 teaspoon	Broad trace minerals, natural plant hormones supporting rooting and establishment.	Low rate, high value. Universal addition for every transplant.

Variations by Plant Family — Add to Base Recipe

Plant Family	Examples	Add to Base	Reason	Avoid
Solanaceae	Tomato, pepper, eggplant	Feather meal or fish meal (1 tbsp)	Heavy feeders, long season — sustained nitrogen supports continuous fruiting	Blood meal at transplant — suppresses mycorrhizal establishment
Alliums	Garlic, onion, leek	Gypsum (1 tbsp)	Sulfur improves flavor development and bulb formation. Calcium for cell structure.	Excess nitrogen — drives top growth over bulb development
Brassicas	Cabbage, kale, broccoli, kohlrabi	Neem seed meal (1 tbsp)	Pest suppression for soil insects and fungal pressure. Moderate nitrogen release.	Fresh manure — excess nitrogen and pathogen risk for leafy crops
Cucurbits	Squash, cucumber, melon	Extra worm castings (½ cup total)	Fast-growing, heavy feeders — biological richness supports rapid establishment	Nothing additional needed at planting — top dress mid-season if needed
Root Crops	Carrot, beet, parsnip, potato	Minimal — base recipe only or azomite pinch	Excess nutrition drives top growth at expense of root development	High nitrogen amendments — causes forking, hairy roots, poor storage quality
Legumes	Bean, pea	Rhizobia inoculant instead of mycorrhizae	Fix atmospheric nitrogen through root nodule bacteria — do not over-fertilize	Nitrogen amendments — defeats the purpose of nitrogen fixation

Key Principles

Biology first, chemistry second — build a living root zone environment and let it feed the plant
Mycorrhizae and high phosphorus do not mix at transplant — choose one or manage timing carefully
Worm castings are the safest, most universally beneficial amendment — use liberally without risk
Blood meal is a mid-season tool, not a transplant amendment — fast nitrogen suppresses the biological partnerships you are trying to establish
Root crops want lean soil — excess nutrition produces poor quality roots and reduces storage life
Legumes fix their own nitrogen — amending heavily undermines what makes them valuable in rotation

Cover Crop Reference Chart

Northern New England — Workshop and Consulting Reference

Crop	Type	Seeding Window (NH)	Winter Hardy	Primary Benefits	Secondary Benefits	Termination	Cautions	Best Use
Field Peas	Legume	Aug 1 – Sep 15	No — winter kills	Nitrogen fixation via rhizobia bacteria. 50–150 lbs N/acre potential	Fast biomass, weed suppression, good soil coverage	Winter-kills cleanly. No termination needed. Leave the residue in place as surface mulch.	Plant early enough to establish before hard frost. Poor germination in cold soil.	Fall cover on harvested beds. Mix with oats or rye for balanced C:N ratio.
Hairy Vetch	Legume	Aug 1 – Sep 1	Yes — overwinters	Very high nitrogen fixation — up to 200 lbs N/acre. High biomass.	Excellent weed suppression when established. Good spring growth.	Roll-crimp or mow close to the ground at full bloom (at least 50%, ideally 75–100% bloom) and leave it as mulch. Cut earlier and it regrows. If bloom timing will not line up, mow and tarp for 3+ weeks.	Terminate before seed set or it reseeds as a weed. Full bloom arrives late May–June in NH, so it fits crops transplanted in June, not early spring crops.	Spring nitrogen source for heavy feeding crops. Best in rotation with grain crops.
Crimson Clover	Legume	Aug 1 – Aug 20	Partial — may winterkill in NH	Moderate nitrogen fixation. Excellent pollinator forage in spring.	Deep taproot improves drainage. Attractive flowering for beneficial insect habitat.	Mow or roll from early bud to bloom and leave as mulch. Wait 2–3 weeks before direct seeding.	Variable winter hardiness in northern NH — seed 6–8 weeks before first frost. Treat as annual.	Pollinator support. Spring nitrogen. Good between rows in perennial systems.
Winter Rye + Vetch Mix	Legume + Grass	Aug 15 – Sep 30	Yes — both overwinter	Combines nitrogen fixation with high carbon biomass. Best of both.	Excellent weed suppression. Significant organic matter addition.	Roll-crimp when rye is shedding pollen and vetch is in full bloom (late May–June), then transplant straight into the mulch. Or mow and tarp for 3+ weeks.	Allelopathic compounds from rye suppress small-seeded crop germination for 3–4 weeks. Use transplants or large seeds.	The most productive overwintering mix for northern New England. Best ahead of June-transplanted heavy feeders (tomatoes, peppers, squash).
Oats	Grass	Aug 1 – Sep 15	No — winter kills	Fast establishment. Good biomass. Winter-kills cleanly leaving mat.	Suppresses late-season weeds. Protects soil surface. Easy to manage.	Winter-kills. No termination needed. The mat flattens by spring and stays as mulch.	Must establish before hard frost — seeding window is tight in NH.	Ideal under fall manure application. Excellent no-till cover. Best paired with field peas.
Winter Rye	Grass	Sep 1 – Oct 15 (only cover still worth seeding after Oct 1)	Yes — very winter hardy	Extensive fibrous root system. Significant organic matter and biology feeding.	Holds soil through freeze-thaw. Suppresses weeds in spring. Very reliable.	Roll-crimp or mow at flowering (pollen shed, late May–June); earlier cuts regrow. Leave as mulch. Tarping kills it at any stage (3+ weeks).	Allelopathic — suppresses germination of carrots, lettuce, and other small seeds for 3–4 weeks. Transplants and large seeds (beans, squash) unaffected.	Most reliable NH winter cover. Hardpan penetration. High organic matter return.
Buckwheat	Broad-leaf	Jun 1 – Aug 1	No — frost kills	Extremely fast — smothers weeds in 4–6 weeks. Phosphorus scavenging from soil.	Excellent pollinator forage. Breaks pest cycles. Quick turnaround.	Mow within 7–10 days after flowering begins, before seeds harden, and leave as mulch. About 6–7 weeks from seeding.	Summer only. Very frost sensitive. Must terminate before heavy seed set.	Summer gap filler between spring and fall crops. Weed suppression. Phosphorus cycling.
Sorghum-Sudan	Grass	Jun 1 – Jul 15	No — frost kills	Massive biomass. Deep roots break severe compaction. High carbon addition.	Suppresses nematodes and soilborne pathogens. Excellent for problem areas.	Mow when 2–3 ft tall; repeat cuts stay on the surface as mulch. Frost kills the final regrowth.	Very large — can be difficult to manage at small scale. Not for small beds.	Large-scale soil rehabilitation. Severe compaction areas. Pathogen suppression.
Field / Tillage Radish	Brassica	Aug 1 – Sep 1	No — winter kills	Deep taproot (6–18") breaks hardpan. Channels persist into spring for drainage and roots.	Scavenges nitrogen from deep soil. Reduces compaction. Winter-kills cleanly.	Winter-kills. Decomposes by spring leaving open channels.	Pungent smell when decomposing in spring — normal and temporary.	Hardpan rehabilitation. Drainage improvement. Pairs well with peas and oats in fall mix.
Mustard	Brassica	Aug 1 – Sep 15	Partial	Biofumigation — glucosinolates released on termination suppress soilborne pathogens and nematodes.	Moderate biomass. Fast establishment.	No-till default: mow at bloom and leave as mulch. Biofumigation only works when cells are ruptured and worked into the soil, so reserve that for a bed with confirmed soilborne disease.	Biofumigation requires incorporation, which conflicts with no-till. Skip before or after brassica cash crops — shares their pests. Non-mycorrhizal.	Soilborne disease or nematode pressure. Rotation between brassica crops.
Oats + Field Peas	Mix	Aug 1 – Sep 15	No — both winter kill	Balanced carbon-to-nitrogen ratio. Nitrogen fixation plus biomass. Both winter-kill cleanly.	Excellent weed suppression. Easy spring management — no termination needed.	Winter-kills. Residue mat ready for spring planting with minimal disturbance.	None significant. Most forgiving and manageable mix for home gardens.	Best all-purpose fall cover for NH home gardens. Ideal under fall manure application.
Radish + Peas + Winter Rye	Mix	Aug 1 – Sep 10	Rye overwinters; radish and peas winter-kill	Hardpan penetration, nitrogen fixation, and overwintering biomass in one seeding.	Deep biology feeding from three root types. Excellent soil rehabilitation mix.	Radish and peas winter-kill. Roll or mow the rye at flowering, or tarp 3+ weeks, and plant through the mulch.	Rye allelopathy — use transplants in spring, or wait 3–4 weeks before direct seeding small seeds.	Soil rehabilitation situations. Compacted or depleted soils. Best 3-way mix for northern gardens.

Termination — Mulch in Place

Kill the cover on the surface and plant through it. The residue becomes the mulch: it holds moisture, blocks weeds, feeds soil biology, and leaves the soil structure and fungal networks intact. Incorporation is a last resort.

Preferred methods, in order: winter-kill (no work at all), roll-crimp, mow and leave, tarp. All four leave the residue on the surface.
Timing is everything for rolling and mowing: grasses at flowering (pollen shed), legumes at full bloom. Cut earlier and the cover grows back.
Tarping kills a cover at any growth stage — mow or roll first, then cover with a silage tarp for at least 3 weeks (faster in hot weather). Useful when rye and vetch do not flower at the same time.
Transplants and large seeds (beans, squash, corn) go directly into the residue. Small seeds need the residue raked aside, or a winter-killed bed.
Early spring crops need nitrogen faster than a fresh no-till cover releases it in cold soil. Put winter-killed covers ahead of early crops and living winter-hardy covers ahead of June crops.

Cover Crop Rotation — What to Plant Before What

One simple rule: if you will plant early in spring, sow a cover that dies over winter. If you will plant in June, sow a cover that lives through winter.

Next year you are planting…	Sow this cover	When to sow	What to do in spring
Early crops peas, lettuce, spinach, cabbage, broccoli, carrots, beets	Oats + peas (oats alone before carrots and beets)	August to early September	Nothing to cut — it dies over winter. Plant right through the dead mat. Rake it aside first for tiny seeds like carrots.
Warm crops tomatoes, peppers, squash, cucumbers	Winter rye + hairy vetch	Early to mid September	It comes back green in spring. In early June, when it flowers, flatten or cut it, leave it lying as mulch, and set your transplants into it.
Beans	Winter rye	September to mid-October — good for beds cleared late	When it flowers in June, flatten or cut it and plant bean seeds right into it.
Nothing — bed is empty in summer	Buckwheat	June to July	Cut it when it flowers (about 6 weeks) and leave it as mulch. Then plant your fall crop or garlic.

Cover	Late summer	Fall	Winter	Spring	Early summer	Mid-summer
Oats + peas	Sow	Grows	Dies — mulch	Plant early crops	Crops grow	Crops grow
Rye + vetch		Sow	Rests	Grows	Flatten + plant	Crops grow
Winter rye		Sow	Rests	Grows	Flatten + plant beans	Beans grow
Buckwheat					Sow	Cut + plant fall crop

Sow Cover growing Dead cover left as mulch Flatten or cut — leave as mulch Your crops

Three Things to Remember

Cut or flatten only when the cover is flowering. Cut it sooner and it grows back.
Leave everything on top as mulch. No digging it in.
Timing off? Cut it and cover the bed with a tarp for 3 weeks — that finishes it off.

Fits the four-bed rotation on the Companion Planting chart: rye + vetch before tomatoes and squash, oats before root crops and greens, rye before beans, oats + peas before the cabbage family.

Sources: UMass New England Vegetable Management Guide (cover crops); SARE, Managing Cover Crops Profitably; UNH Extension, Low and No-Till Gardening; High Mowing Organic Seeds, cover crop planning for Northeast vegetable farms; Pam Dawling, Sustainable Market Farming; Rodale Institute, organic no-till; UMass and UMaine/Cornell tarping guides; Penn State Extension.

Application Notes — Northern New England

Seeding windows are approximate for central and northern NH. Southern NH and protected microclimates may extend windows by 1–2 weeks on either end.

All seeding rates assume broadcast seeding with light raking or pressing into the surface. Drilling needs roughly 20–30% less seed. Rates converted from per-acre extension figures (1 acre = 43,560 sq ft).

Suggested Seeding Rates — Broadcast

Crop	Lbs per 1,000 sq ft	Notes
Field Peas	2.5–3.5 lb	Large seed — rake in or press; surface seed germinates poorly. Inoculate with rhizobia if not previously grown
Hairy Vetch	0.6–1 lb	Inoculate with rhizobia
Crimson Clover	0.5–0.7 lb	Small seed — do not bury deep
Oats	2.5–3.5 lb	Heavier rates give a thicker winter-killed mulch mat
Winter Rye	2–3.5 lb	Mid-Sept rate. Seeding later needs more: about 5 lb by Oct 1, 5.5–6 lb by mid-Oct
Buckwheat	2–2.5 lb	Mow before seed set
Sorghum-Sudan	1–1.25 lb	Needs warm soil (60°F+). Large beds only
Field Radish	0.25–0.4 lb	Small seed — surface broadcast, light press
Mustard	0.25–0.35 lb	Mow and leave as mulch unless biofumigating
Oats + Peas Mix	1 + 2.75 lb	Most versatile fall mix for home gardens (40 + 120 lb/acre broadcast)
Rye + Vetch Mix	2 + 0.75–1 lb	Best overwintering mix ahead of June transplants (80–90 + 30–40 lb/acre broadcast)
Radish + Peas + Rye	0.15 + 2.5 + 1 lb	No published rate for this exact mix — built by the standard mix rule: keep the legume near full rate, cut grass and brassica rates

Fresh Manure + Cover Crop — Fall Application Notes

Fresh manure applied over standing or frost-killed cover crop before shredded leaf mulch is a legitimate and effective fall practice in NH. Minimum 90–120 days before harvest depending on crop contact with soil — fall application clears this threshold comfortably for spring planting.
Oats are the ideal pairing for fresh manure application — they winter-kill cleanly, their biomass buffers direct manure-to-soil contact, and the combined system composts in place over winter.
Apply manure after oats have established reasonable biomass or have been knocked down by frost. Heavy fresh manure on young, actively growing cover crop can mat and reduce effectiveness.
Cover with 4–6 inches shredded leaves after manure application. Shredded leaves retain moisture, insulate the manure layer, reduce nitrogen volatilization, and add organic matter as they break down.
Horse manure caution: ask about ivermectin deworming rotation. Ivermectin compounds in fresh horse manure are documented to harm earthworm populations. Breakdown is variable — source matters.
Cow manure fresh application risk is lower — ruminant digestion produces less soluble nitrogen and lower pathogen load than horse manure at equivalent freshness.

Pest, Disease & Deficiency Reference

New England Vegetable Gardens — Organic Management Reference

Common Garden Pests — New England

Common mistakes column highlights the most frequent wrong responses — the instinctive reach that makes the problem worse.

Pest	Crops Affected	How to Identify	Organic Controls	Beneficial / Cultural Notes	Common Mistakes
Chewing Insects
Tomato / Tobacco Hornworm	Entire Solanaceae family — tomato, pepper, eggplant, potato. Same family, same vulnerability.	Large green caterpillar with white diagonal stripes and red or black horn. Up to 4" long. Look for large irregular holes in leaves and dark green frass pellets.	Hand pick — most effective. BT (Bacillus thuringiensis) spray on young caterpillars. Parasitic wasps (braconid) — if white egg cocoons visible on hornworm, leave it. Wasps will emerge and parasitize next generation.	Braconid wasps are primary natural predator — do not kill parasitized hornworms. Broadfork beds at fall cleanup to expose pupae to frost and predators without destroying soil structure. Chickens or ducks in the garden after harvest find and eat pupae naturally. Rotate solanaceae crops annually — pupae that survive emerge to find no host crop.	Ignoring small caterpillars — they grow fast and damage accelerates. Broad-spectrum sprays kill braconid wasps that would otherwise control population naturally. Deep tillage to destroy pupae — broadforking achieves the same exposure without inverting soil biology.
Cabbage Worm (Imported)	All brassicas — cabbage, broccoli, kale, kohlrabi, Brussels sprouts, cauliflower	Velvety pale green caterpillar, up to 1.5". Look for irregular holes in leaves and green frass. White butterfly with black spots (Pieris rapae) is the adult — presence means eggs are being laid.	BT spray — most effective organic control. Hand pick eggs (pale yellow, ribbed, upright on leaf undersides). Row cover before adult flight — most reliable prevention. Spinosad for heavy infestations.	Row cover from transplant is the highest-return prevention. Parasitic wasps and ground beetles are significant natural predators — maintain diverse plantings nearby.	Waiting too long — small holes become defoliation quickly. Using broad-spectrum sprays that kill natural predators alongside the pest.
Cabbage Looper	All brassicas. Also lettuce, spinach, celery.	Pale green caterpillar that loops its body when moving. Similar damage to cabbage worm but looper is lighter green and moves differently. Both may be present simultaneously.	BT spray — effective on young larvae. Row cover. Hand pick. Spinosad.	Often misidentified as cabbage worm — management is identical. Both respond to BT. Both are controlled by same beneficial insects.	Treating as separate problem from cabbage worm — identify which or both are present, management is the same.
Colorado Potato Beetle	Potato, eggplant, tomato, pepper — full Solanaceae family	Distinctive orange and black striped adult beetle. Orange egg clusters on leaf undersides. Orange larvae with black spots.	Hand pick adults, larvae, and egg clusters daily — very effective at small scale. Neem oil on young larvae. Spinosad. Straw mulch deters adults from reaching plants. Rotate crops.	Rotate potatoes and solanaceae crops annually — adults overwinter in soil where host crop grew. Strong populations build quickly without intervention.	Skipping daily scouting — populations explode in days. Pyrethrin sprays kill beneficial insects alongside beetles.
Flea Beetle	Brassicas most severely. Also eggplant, potato, tomato.	Tiny (1-2mm) black or bronze jumping beetles. Shothole damage — many small round holes in leaves. Seedlings most vulnerable.	Row cover on transplants — most effective. Diatomaceous earth around base. Kaolin clay on leaves deters feeding. Radish trap crop — flea beetles prefer radish, sacrifice to protect main crop.	Flea beetle pressure decreases as plants mature and establish. Most damage to seedlings and young transplants. Healthy established plants tolerate flea beetle pressure.	Over-spraying established plants — damage looks dramatic but mature plants outgrow it. Killing beneficial ground beetles that prey on flea beetle larvae.
Squash Vine Borer	Zucchini, summer squash most vulnerable. Winter squash and butternut more resistant.	Moth lays red-brown eggs at stem base. Look for sawdust-like frass at stem entry point. Plant wilts suddenly despite adequate water — borer is inside the stem.	Prevention only — row cover until flowering. Wrap stems in foil at soil level. Inject BT into stem at entry hole. Mound soil over damaged stems to encourage re-rooting.	Plant resistant varieties — butternut squash significantly more resistant than zucchini. Second succession planting in late June escapes first moth generation.	Trying to spray after infestation — borer is inside the stem, spray cannot reach it. Discarding plants — stem mounding and re-rooting saves many plants.
Cucumber Beetle (Striped & Spotted)	All cucurbits — cucumber, squash, melon, pumpkin. Spreads bacterial wilt disease.	Yellow-green beetle with black stripes (striped) or spots (spotted). Feeding damage on leaves and flowers. More damaging as wilt vector than from direct feeding.	Row cover until flowering — must remove for pollination. Kaolin clay on leaves. Trap crop — blue Hubbard squash as perimeter trap. Beneficial nematodes for larvae in soil.	Bacterial wilt is the primary concern — cucumber beetles carry it plant to plant. Wilted plant that does not recover despite watering — do the stem test: cut stem, touch sticky thread between cut ends — positive for bacterial wilt.	Ignoring beetles on the assumption that feeding damage is the only issue — wilt transmission is the real threat. Leaving infected plants — remove immediately to reduce inoculum source.
Japanese Beetle	Broad — roses, beans, basil, grapes, fruit trees. Vegetables less primary target.	Metallic green and copper adult beetle. Skeletonized leaves — feeding between veins. Grubs in soil damage roots.	Hand pick in early morning when sluggish. Row cover on high-value crops during peak flight (July). Milky spore for grub control — long-term soil treatment. Neem oil.	Do not use Japanese beetle traps near the garden — they attract more beetles than they catch. Traps increase beetle pressure in the area.	Beetle traps placed near garden — documented to increase beetle damage. Killing ground beetles pursuing grubs in soil.
Aphids	Broad — most vegetable crops. Particular pressure on brassicas, beans, tomatoes, lettuce.	Soft-bodied, pear-shaped insects in green, black, yellow, or gray. Colonies on new growth and leaf undersides. Sticky honeydew residue. Attended by ants.	Strong water spray dislodges colonies. Insecticidal soap — direct contact required. Neem oil. Encourage beneficials — lady beetles, lacewings, parasitic wasps consume large numbers.	Ants farm aphids for honeydew and protect them from predators — control ants around plants to allow beneficial predation. Lady beetle larvae consume more aphids than adults.	Broad-spectrum sprays that kill lady beetles, lacewings, and parasitic wasps — the beneficial community will control aphids better than any spray if protected.
Slugs & Snails	Broad — seedlings, lettuce, brassicas, strawberries most vulnerable.	Irregular holes with smooth edges, often through leaf center. Slime trails visible in morning. Active at night and in wet conditions.	Iron phosphate bait (Sluggo) — OMRI listed, safe around pets and wildlife. Diatomaceous earth around bed edges when dry. Beer traps. Copper tape as barrier. Hand pick at night with flashlight.	Slugs thrive in cool, moist conditions under mulch. Pull mulch back from direct contact with seedling stems in wet springs — maintain mulch on beds but keep a clear zone around transplants until established. Encourage ground beetles — primary slug predators.	Salt — kills on contact but damages soil and is not a management strategy. Metaldehyde baits — toxic to pets and wildlife. Removing all mulch to reduce slug habitat — ground beetles that prey on slugs also need mulch cover.
Thrips	Onions, garlic, peppers, tomatoes. Significant in dry conditions.	Tiny (1mm), slender insects — silver-gray streaking on leaves, distorted new growth. Onion thrips cause silver-white papery patches on leaves.	Insecticidal soap. Spinosad — most effective organic control for thrips. Reflective mulch disorients adults. Remove and destroy heavily infested plant material.	Thrips pressure increases in hot, dry weather. Consistent irrigation reduces pressure. Blue sticky traps for monitoring.	Missing early damage — thrips damage mimics nutrient deficiency or wind damage. Delayed treatment allows population explosion.
Spider Mites	Broad in hot dry conditions — tomatoes, peppers, cucumbers, beans.	Fine webbing on leaf undersides. Stippled, bronzed leaves. Tiny moving dots on underside with hand lens. Populations explode in heat and drought.	Strong water spray — disrupts webbing and dislodges mites. Insecticidal soap. Neem oil. Maintain consistent irrigation — drought-stressed plants attract mites.	Predatory mites (Phytoseiidae) — natural enemies, killed by most sprays. Avoid broad-spectrum sprays which remove predatory mite populations and cause outbreaks.	Pyrethrin sprays — kills predatory mites, causes secondary spider mite outbreaks. Allowing drought stress — stressed plants are primary targets.
Whitefly	Tomatoes, peppers, cucumbers, brassicas — especially in sheltered or greenhouse conditions.	Tiny white flying insects on leaf undersides. Honeydew and sooty mold on leaves. Clouds of insects when plant disturbed.	Yellow sticky traps for monitoring and control. Insecticidal soap on leaf undersides — direct contact required. Neem oil. Reflective mulch disorients adults.	Whitefly pressure highest in sheltered gardens and greenhouses. Good air circulation reduces pressure significantly. Parasitic wasps (Encarsia formosa) effective in greenhouse settings.	Spraying tops of leaves — whiteflies are on undersides. Missing early population buildup when sticky traps would control effectively.
Leafhoppers	Broad — potatoes, beans, lettuce, brassicas. Transmits aster yellows disease.	Small (3mm) wedge-shaped insects, green or brown, jump sideways when disturbed. Stippled, curled leaf margins. Yellowing from edges inward.	Row cover. Kaolin clay. Insecticidal soap. Remove infected plants — aster yellows has no cure once present.	Leafhoppers overwinter in weeds and crop debris. Clean field margins reduce overwintering populations. Aster yellows symptoms — yellowing, stunted growth, distorted flowers — confirm with plant removal.	Leaving aster yellows-infected plants — disease spreads to adjacent plants through leafhopper feeding.

Fungal Diseases — New England

Prevention and removal are the primary organic tools. Most fungal diseases have no organic cure once established — scout early and act fast.

Disease / Fungal	Crops Affected	How to Identify	Organic Controls	Prevention	Common Mistakes
Fungal Diseases
Early Blight (Alternaria solani)	Tomatoes and potatoes primarily. Occasionally peppers and eggplant — full solanaceae family. One of the most common diseases in NH vegetable gardens.	Brown to black lesions with concentric rings (target pattern) on older lower leaves first. Yellow halo around lesion. Progresses upward through plant over season. Distinct target-ring pattern distinguishes it from late blight.	Remove infected lower leaves immediately — slows upward spread. Copper fungicide spray applied preventively before symptoms appear in high-risk conditions. Consistent watering at soil level, not overhead. Mulch to prevent soil splash onto lower leaves — primary infection route.	Early blight spores overwinter in infected plant debris and soil and reinfect the following season. Remove and bag all infected plant material at season end — do not compost. Rotate solanaceae out of the bed for 2 to 3 years minimum — spore load decreases significantly without a host crop. Trichoderma soil drench at bed preparation suppresses Alternaria through biological competition and is consistent with no-till organic practice. Active finished compost builds the diverse microbial community that suppresses pathogen populations long-term. Solarization (clear plastic, 4–6 weeks in July–August) reduces spore load but also kills beneficial soil biology and is a last resort for heavily infected beds only. Avoid overhead watering — wet foliage is the primary infection pathway.	Overhead watering — spreads spores efficiently up the plant. Leaving infected leaves on plant or dropping them on the soil surface — adds to the spore bank for next season. Composting infected material — Alternaria survives most home compost temperatures. Planting solanaceae in the same bed the following season — spore load rebuilds immediately with a host present.
Late Blight (Phytophthora infestans)	Tomatoes and potatoes — the same pathogen that caused the Irish potato famine.	Water-soaked, greasy-looking lesions on leaves and stems, often with white fuzzy growth on undersides in humid conditions. Rapid collapse of tissue. Dark brown lesions on fruit and tubers.	Remove and destroy all infected material immediately — bag and dispose, do not compost, do not leave on soil surface. Copper fungicide preventively in high-risk conditions (cool, wet weather). Destroy all infected plant material including roots and any remaining tubers.	Monitor weather — late blight spreads explosively in cool (60-70°F), wet conditions. Community-level problem — spores travel miles on wind. Remove volunteer potato plants — primary inoculum source.	Composting infected material — spores survive composting temperatures and re-infect next season. Leaving infected plants hoping they recover — late blight does not slow down. Saving tubers from infected potato plants for next year's seed — infection travels with the tuber.
Powdery Mildew	Squash, cucumber, melon most severely. Also peas, beans, brassicas late season.	White powdery coating on leaf surfaces — upper and lower. Does not need wet conditions to spread unlike most fungal diseases. Infected leaves yellow and die.	Baking soda spray (1 tbsp per gallon water + few drops dish soap) — changes surface pH. Dilute milk spray (40% milk, 60% water) — documented effectiveness. Neem oil. Remove infected leaves.	Good air circulation is primary prevention — don't crowd cucurbit plants. Resistant varieties available and worth selecting. Powdery mildew late in season is cosmetic — plants have usually set their fruit.	Overhead watering to wash off mildew — spreads spores and does not remove established infection. Pulling plants at first sign — late season powdery mildew rarely affects yield significantly.
Downy Mildew	Cucumbers most severely. Also lettuce, brassicas, spinach, basil.	Yellow angular patches on upper leaf surface (bounded by leaf veins). Gray-purple fuzzy growth on leaf undersides. Distinct from powdery mildew — requires wet conditions.	Copper fungicide preventively. Remove infected leaves. Improve air circulation. Avoid overhead watering.	Requires wet, humid conditions — most severe in cool wet springs. Resistant cucumber varieties available. Basil downy mildew — devastating, spreads rapidly. Remove at first sign.	Confusing with powdery mildew — management differs. Powdery mildew is on upper surface and dry conditions. Downy mildew is on undersides in wet conditions.
Damping Off	Seedlings of all crops — most common in early spring indoor starts.	Seedling stem collapses at soil level — pinched, water-soaked appearance. Rapid death of seedlings that appeared healthy. Often affects groups of seedlings.	Use sterile seed starting mix — never garden soil. Ensure drainage. Water from below when possible. Allow soil surface to dry between waterings. Chamomile tea drench — mild antifungal.	Caused by soilborne fungi (Pythium, Rhizoctonia) thriving in cool, wet, poorly drained conditions. Prevention is the only effective strategy — no cure once seedlings collapse.	Using garden soil for seed starting — carries damping off fungi. Overwatering seedlings — most common cause. Covering seed starting trays without adequate ventilation.
Club Root (Plasmodiophora brassicae)	All brassicas — cabbage, broccoli, kale, turnip, radish, arugula.	Wilting during warm days, recovering at night. Stunted growth. Swollen, distorted club-shaped roots — visible only when plant pulled. Plants never thrive.	No organic cure once established. Lime soil to raise pH above 7.2 — club root thrives in acid soils. Long rotation — 7+ years out of brassicas if club root confirmed. Remove and destroy all infected plants including roots.	Soil pH is the primary management lever — club root cannot sporulate effectively above pH 7.2. Spores persist in soil 20+ years. Do not move soil from infected areas.	Composting infected roots — spores survive composting. Short rotation — club root spores persist for decades. Moving transplants or soil from infected beds to new areas.

Emerging & Expanding Pest Watch List

Pests moving north into New England as winters moderate. Not yet primary concerns in NH but worth monitoring.

Pest	Current Status in NH/NE	Crops at Risk	Identification	Action
Spotted Lanternfly	First NH detection in Salem, August 2026 — a small number found, no established population yet. Spreading north; establishment expected.	Grapes, hops, fruit trees, vegetables	1" adult with red hindwing visible in flight. Gray-brown forewings with black spots. Egg masses — gray putty-like patches on hard surfaces.	Report sightings at NHBugs.org (NH Dept. of Agriculture, Markets & Food). Destroy egg masses. Do not transport firewood from affected areas.
Brown Marmorated Stink Bug	Established southern NH, expanding north	Tomatoes, peppers, beans, corn, fruit	Shield-shaped, mottled brown, 3/4". Banded antennae and legs. Piercing-sucking damage — corky patches on fruit.	Exclude from greenhouse. Kaolin clay on fruit. Vacuuming adults. No effective organic spray — physical exclusion is primary control.
Swede Midge	Established VT and NH — underdiagnosed	All brassicas — most damaging to broccoli, cauliflower, Brussels sprouts	Tiny (2mm) tan fly. Damage: distorted, scarred growing points. Stunted and twisted new growth. Often misdiagnosed as herbicide damage.	Row cover from transplant — primary control. Monitor with yellow sticky traps. Report unusual brassica distortion — often misidentified.
Squash Bug	Increasing in NH and ME — historically more mid-Atlantic	All cucurbits — pumpkins and winter squash most vulnerable	Flat gray-brown bug, 5/8". Copper egg clusters on leaf undersides. Nymphs gray with black legs. Wilting and vine death.	Hand pick eggs and nymphs. Trap boards under plants overnight — bugs shelter beneath. Row cover until flowering. Resistant varieties.

Beneficial Insects — Protect and Encourage

Every organic pest management decision should ask: what does this do to the beneficial community? Broad-spectrum sprays that kill pests also kill the predators that would keep pest populations in check long-term.

Beneficial	What It Controls	How to Identify	How to Attract	Never Do
Lady Beetle (Ladybug)	Aphids — larvae consume more than adults	Familiar red/orange with black spots. Larvae are gray-orange alligator-shaped — commonly misidentified and killed.	Allow aphid colonies to establish before spraying — lady beetles follow food source. Diverse flowering plants for adults.	Kill lady beetle larvae — they look alarming but are voracious aphid predators.
Lacewing	Aphids, thrips, small caterpillars, mites, whitefly — larvae are generalist predators	Delicate green insect with large iridescent wings. Larvae are small, tan, and alligator-shaped with curved jaws.	Plant dill, fennel, coriander, and other umbellifers. Reduce night lighting near garden — attracts adults.	Broad-spectrum sprays during peak aphid season when lacewing populations are building.
Braconid Wasp	Hornworms — larvae parasitize caterpillars	Tiny wasp, often overlooked. Identified by white egg cocoons protruding from parasitized hornworm body.	Allow some hornworm damage early season — braconids follow. Plant dill and parsley as adult nectar source.	Kill hornworms bearing white egg cocoons — the wasp larvae inside will emerge and parasitize next generation.
Ground Beetle	Slugs, soil-dwelling larvae, flea beetle pupae, weed seeds	Large, fast-moving black or iridescent beetles. Active at night. Found under boards and mulch.	Permanent mulched pathways provide habitat. Reduce or eliminate tillage — ground beetles nest in soil. Avoid pesticides.	Till pathways — destroys ground beetle nesting habitat. Broad-spectrum soil drenches.
Parasitic Wasp (Trichogramma)	Caterpillar eggs — prevents hatching before damage occurs	Microscopic — not visible to naked eye. Presence indicated by darkened (parasitized) caterpillar eggs.	Plant nectar-rich flowers throughout garden — umbellifers especially. Avoid spraying during flowering.	Any broad-spectrum spray — these tiny wasps are killed easily and provide enormous pest control value.

Plant Deficiency & Health Reference

Visual Diagnosis Guide — Organic Corrections — Common Mistakes

How to Diagnose a Deficiency — The Mobile vs Immobile Key

The single most useful diagnostic tool. Mobile nutrients move from old tissue to support new growth when scarce — symptoms appear in old leaves first. Immobile nutrients cannot be relocated — symptoms appear in new growth first. This distinction narrows the diagnosis before you look at anything else.

First Question	Mobile Nutrients — Old Leaves First	Immobile Nutrients — New Leaves First	Before Treating — Three Checks
Where are the symptoms appearing? Old, lower leaves — mobile nutrient deficiency. New, young growth or fruit — immobile nutrient deficiency.	Plant relocates these nutrients to new growth when scarce. Old leaves show symptoms first. Nitrogen — uniform yellowing, older leaves Phosphorus — purple undersides, older leaves Potassium — brown scorched margins, older leaves Magnesium — interveinal yellowing, older leaves	Plant cannot relocate these. Deficiency shows in youngest tissue and developing fruit. Calcium — tip burn, blossom end rot, fruit issues Iron — interveinal yellowing, new leaves only Sulfur — uniform yellowing, new leaves only Boron — distorted new growth, cracked fruit	Before reaching for any amendment: 1. Check soil pH — most problems are pH-related, not nutrient absence 2. Check watering — inconsistent moisture causes delivery failure, not deficiency 3. Check roots — compaction or disease prevents uptake regardless of soil levels Then consider amendment.

Nutrient Deficiency Reference

Common mistakes column (highlighted) identifies the most frequent wrong responses — including the most over-applied fix in home gardening: Epsom salt for blossom end rot.

Nutrient	Mobile?	Symptoms Appear On	Visual Symptoms	Crops Most Affected	Organic Correction	Common Mistakes
Mobile Nutrients — Symptoms Appear on OLDER / LOWER Leaves First
Nitrogen (N)	YES — Mobile	Older, lower leaves first	Uniform yellowing of older leaves progressing upward. Pale green overall plant color. Stunted growth. Older leaves yellow and drop.	All crops — especially heavy feeders: tomatoes, corn, brassicas, squash	Compost top dress. Blood meal (fast) or feather meal (sustained). Fish emulsion as foliar. Cover crops and soil biology long-term.	Applying nitrogen every time any yellowing appears — half of yellowing issues are not nitrogen. Excess nitrogen drives leaf growth at expense of fruit and root development.
Phosphorus (P)	YES — Mobile	Older leaves, stems, undersides	Purple or reddish discoloration on leaf undersides and stems. Dark green leaves may also show purple tint. Stunted roots. Slow establishment.	Seedlings and transplants. Root crops. Fruiting crops at establishment.	Compost — most soils have adequate phosphorus with good biology. Bone meal only if confirmed deficient. Mycorrhizal inoculant — enhances phosphorus uptake without adding more.	Over-applying bone meal preemptively — excess phosphorus suppresses mycorrhizal activity. Treating purple seedlings in cold soil as deficiency — cold temperatures mimic phosphorus deficiency and resolve as soil warms.
Potassium (K)	YES — Mobile	Older leaves, leaf margins	Brown scorching and curling of older leaf margins. Yellow then brown leaf edges while center remains green. Weak stems. Poor fruit quality and storage.	Fruiting crops — tomatoes, peppers, squash. Root crops. All crops under stress.	Compost. Wood ash (raises pH — use with caution). Greensand (slow, long-term). Sul-Po-Mag for combined K and Mg without pH change.	Confusing potassium scorch with drought or salt damage — symptoms similar. Applying wood ash to already alkaline soil — raises pH further.
Magnesium (Mg)	YES — Mobile	Older leaves first — interveinal	Interveinal chlorosis on older leaves — yellowing between veins while veins stay green. Classic symptom on tomatoes and peppers mid-season.	Tomatoes, peppers, roses. Heavy-producing plants late season.	Dolomitic lime if pH adjustment also needed. Sul-Po-Mag for magnesium without pH change. Epsom salt as foliar drench — 1 tbsp per gallon — only when deficiency confirmed.	Using Epsom salt to treat blossom end rot — BER is calcium deficiency caused by inconsistent watering, not magnesium deficiency. Routine Epsom salt application without confirmed deficiency — excess magnesium competes with calcium uptake.
Immobile Nutrients — Symptoms Appear on NEW GROWTH / YOUNG Leaves First
Calcium (Ca)	NO — Immobile	New growth and developing fruit	Tip burn on inner lettuce and brassica leaves. Blossom end rot on tomatoes, peppers, squash — dark sunken lesion at blossom end. Distorted new growth.	Tomatoes, peppers, squash — blossom end rot. Lettuce — tip burn. Brassicas — internal tip burn.	Consistent, even watering — primary solution for BER. Mulch to maintain soil moisture. Calcium foliar spray (calcium chloride) directly on developing fruit. Gypsum if soil calcium genuinely low.	Applying Epsom salt for blossom end rot — Epsom salt is magnesium sulfate, not calcium. BER is a calcium delivery problem caused by inconsistent watering, rarely a soil calcium deficiency. Adding more fertilizer when BER is caused by irrigation inconsistency.
Iron (Fe)	NO — Immobile	Young leaves and new growth first	Interveinal chlorosis on young leaves — yellowing between veins while veins stay bright green. Distinct from magnesium deficiency which affects older leaves.	Blueberries, raspberries, acid-loving plants. Vegetables in high pH or waterlogged soils.	Lower soil pH — iron availability drops sharply above pH 7.0. Sulfur to acidify. Chelated iron foliar spray as short-term correction. Improve drainage — waterlogging causes iron unavailability.	Confusing with magnesium deficiency — magnesium shows on old leaves, iron on new leaves. Applying iron in high pH soil — iron becomes unavailable above pH 7.0 regardless of soil iron content.
Sulfur (S)	NO — Immobile	Young leaves and new growth	Uniform yellowing of young leaves — similar to nitrogen but affects new growth rather than old. Sulfur deficiency relatively uncommon in organically amended soils.	Alliums — sulfur is critical for flavor development. Brassicas.	Gypsum (calcium sulfate) — adds sulfur without pH change. Sul-Po-Mag. Most finished compost contains adequate sulfur.	Confusing with nitrogen deficiency — nitrogen symptoms on old leaves, sulfur on new leaves. This distinction alone directs the correct amendment.
Boron (B)	NO — Immobile	Growing tips, new leaves, developing fruit	Distorted, thickened, or brittle new growth. Hollow or corky stem centers. Cracked or deformed fruit. Browning of cauliflower curd. Beet internal browning.	Brassicas — especially cauliflower and broccoli. Beets. Root vegetables. More common in sandy, low organic matter, or high pH soils.	Compost — best long-term source. Borax — 1 tablespoon per 100 sq ft maximum — highly soluble, easy to over-apply. Confirm deficiency before applying.	Over-applying borax — the margin between deficiency and toxicity is narrow. Boron toxicity causes similar leaf edge burn to potassium deficiency.

Three Checks Before Reaching for Any Amendment

Check Soil pH First	Check Watering Consistency Second	Check Root Health Third
Most nutrient availability problems in organic gardens are pH-related rather than actual nutrient absence. Organic soils managed with compost typically have adequate nutrient levels. At pH above 7.5 or below 5.5, multiple nutrients become unavailable regardless of soil content. A simple pH test ($15–25 at any garden center) answers this question before any amendment is purchased.	Calcium and several other nutrients move through the plant with water. Inconsistent watering — wet-dry cycles — disrupts delivery even when soil nutrient levels are adequate. Blossom end rot is the classic example: almost always a watering consistency problem, rarely a soil calcium deficiency. Consistent moisture through mulching resolves the majority of calcium delivery issues without any soil amendment.	Compacted soil, waterlogged roots, root disease, or nematode damage all prevent nutrient uptake regardless of soil nutrient levels. A plant with compromised roots cannot absorb what is available. Pull a struggling plant and examine the root system before diagnosing a deficiency. Healthy roots are white to tan, firm, and branching. Diseased, compacted, or waterlogged roots are brown, slimy, or stunted.

Reference charts from Small Farm Consulting, Danbury NH. Shaded cells mark common mistakes. Questions about your own garden? Call 603-409-7399 or email smallfarmnh@gmail.com.