Companion Planting

Sabine Harvey sharvey1@umd.edu

College ofAgriculture and Natural Resources

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, 23-79 AD• Three Sisters• Sensitive crystallization test? Biodynamics.

Be Aware: Allelopathy

• Greek: Allelon = “of each other”, pathy = “to suffer”

• Broccoli and cabbage• 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:Predators

Good Guys: Parasitoids

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 trials they attracted pests• AND they grow better in 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 nutrientsplants 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

Think Twice!

• Amaranth

• Comfrey: Symphytum officinale, Russian comfrey - Symphytum x uplandicum

• Flax

• Tansy

Happy Gardening!

Sources

• Companion Planting, Susan Mclure, Rodale Press.

• Great Garden Companions, Sally Jean Cunningham, Rodale Press

• Companion Planting: Basic Concepts and Resources, ATTRA Publication

Resources

• Grow It! Eat It!http://www.extension.umd.edu/growit

– We have all types of practical food gardening tips and information. Check out our popular blog!

• Home and Garden Information Centerhttp://www.extension.umd.edu/hgic

– Here you will find factsheets, photos, and videos. You can also subscribe to the free monthly e-newsletter.

– We answer gardening questions 24/7…just click “Ask Maryland’s Garden Experts”

• Maryland Master Gardener Programhttp://www.extension.umd.edu/mg

– Consider becoming a trained MG volunteer!

This program was brought to you by the

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Kent County

University of Maryland Extension