Many experienced gardeners already know that having a diverse mix of plants helps give you a beautiful and healthy garden. Some also believe that certain plant combinations have extraordinary (some even believe mysterious) powers for helping each other grow. Scientific study of companion planting has confirmed that some combinations have real benefits unique to those combinations. And practical experience has demonstrated to many gardeners how to combine certain plants for their mutual benefit.
This can be confusing to some people. The best way is to take the average spacing between the two varieties.
Over the centuries companion planting has been used by various people. The “Three Sisters” or De-o-ha-ko were used by the Iroquois American Indians in the Northeast. De-o-ha-ko literally means “our sustainers” or “those who support us”. Companion planting has played a vital role in the survival of people throughout history. When companion plantings are used they help one another grow, thrive and produce higher yields efficiently and with little impact on the environment.
Trap Cropping – one plant will lure bugs and pests away from another plant and serves to distract.
Symbiotic nitrogen fixation – legumes (peas, clover, beans) fix atmospheric nitrogen for their own use and benefit of nearby plants via symbiotic relationship with rhizobium bacteria.
Biochemical pest suppression – certain plants give off chemicals in their roots or aerial parts that suppress or repel pests and protect neighboring plants.
Physical spatial interactions – tall growing plants which love sun sharing space with low growing shade tolerant plants gives higher yields in less space, as well as yielding pest control.
Beneficial Habitats – or refugia is when companion plants provide a desirable environment for beneficial insects and other arthropods, like predatory and parasitic insects which help keep the pest population in balance. Agro-ecologists believe this is a good way to both reduce pest damage and pesticide use.
Security via Diversity – a mixed variety of plants, herbs and vegetables helps limit the possible destruction that can be caused to a single crop or cultivar. Simply mixing cultivars will achieve the diversity needed as the University of California demonstrated with broccoli.
As much as there are plants that are compatible together, there are some that are just as incompatible together as well. It’s equally important to understand which plants don’t work well together in the garden. Sometimes when these vegetables are couples together you may find that growth was stunted or harvests just generally less prolific.
|Asparagus||garlic, onions, potatoes|
|Beans||(alliums) garlic, onions|
|Cabbage Family (broccoli, Brussels sprouts,|
kale, kohlrabi, cauliflower, cabbage)
|tomatoes, strawberries, pole beans, peppers, eggplants, grapes, lettuce|
|Carrots||dill, parsnips, Queen Ann’s lace|
|Celery||corn, potatoes, aster|
|Chards||cucurbits, melons, corn or herbs|
|Chives||beans and peas|
|Cucumber||cauliflower, potatoes, basil, sage, rue|
|Marigolds, French||Beans, cabbage|
|Peas||chives, potatoes, onions, gladiolus, grapes|
|Pepper, sweet bell||fennel, kohlrabi, apricot trees|
|Potato||Asparus, kohlrabi, rutabage, fennel, turnip, pumpkin, squash, tomatoes, sunflowers, cucumbers|
|Radish||hyssop, cabbage, cauliflower, Brussels sprouts, turnips|
|Strawberry||Cabbage, broccoli, Brussels sprouts, cauliflower, kohlrabi|
|Tomato||dill, fennel, apricot trees, potatoes, kohlrabi, corn|
|Turnip||potatoes, radishes or other root vegetables, delphinium, larkspur, mustard|