Companion Planting Sabine Harvey
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What is companion planting? The establishment of two or more plant species in close proximity so that some cultural benefit is derived
History Pliny the Elder, AD Three Sisters Sensitive crystallization test? Biodynamics.
Be Aware: Allelopathy Greek: Allelon = “of each other”, pathy = “to suffer” Broccoli and cabbage Fennel Marigolds Crabgrass Sunflowers Black Walnut
Various Mechanisms Biodiversity/beneficial insects Pest control (biochemical, trap crops) Symbiotic relationship Increased crop diversity Physical interaction (shade, fast-slow growing)
Beneficial insects Any plant in the aster, mint or carrot family Flowers during entire season
Good Guys
Pest Control, maybe Usually heavily scented, herbs Different color Pest repellent or trap crop
Nasturtiums Deter pests from beans, cabbages and squash family But in some trails they attracted pests AND they need poor soil
Marigolds Tagetes patula – French Marigold Controls root-knot nematodes BUT Can also be allelopathic: Beans, Cabbages
Physical interactions Three sisters: perfect example
How to start? Pick your favorite veggies Do you have the space? Avoid planting together: plants of same family (except cabbages) plants that use the same nutrients plants with similar root zones
Beans and Peas Potatoes Corn, Squash, Cucumber Summer Savory, Dill Pole beans create shade for lettuce Not with Onion Family or Marigolds
Cabbage Family Potatoes Any strong smelling plant Use space between plants Not with marigolds
Carrots Grows well with almost anything Onion Family Keep away from dill, parsnips
Lettuce Plant below/behind tall crops in summer Onions and roots crops Anything Sensitive to decaying Rye
Onion Family Good with anything, except legume family Don’t forget garlic!
Potatoes Beans Plant with fast growing spring veggies Do not plant with tomatoes, raspberries, squash family
Squash Family Beans and corn Radishes! Nasturiums?
Tomatoes Onion/Garlic or strong smelling herbs Asparagus Basil! Very sensitive to Black Walnut Not near fennel, potatoes or corn
Cover crops Organic matter (feed the soil) Tap roots Suppress weeds Prevent soil erosion
Crimson Clover Oilseed Radish Winter Rye
Think twice! Amaranth Comfrey: Symphytum officinale, Russian comfrey - Symphytum x uplandicum Flax
Sources Companion Planting, Susan Mclure. Great Garden Companions, Sally Jean Cunningham Companion Planting: Basic Concepts and Resources, ATTRA Publication
Resources Home and Garden Information Center (HGIC) – – hgic.umd.edu Grow-It-Eat-It website – GrowIt.umd.edu Master Gardener state website – mastergardener.umd.edu
This program was brought to you by Sabine Harvey University of Maryland Extension Kent County