Companion planting is a way to help ensure that your favorite plants grow and thrive. When certain plants grow as neighbors to certain other plants, they have preferences, just like humans do, about whom they like and whom they dislike. When incompatible plants grow in the same area, they might not grow as well as when they live near their friends and the combination of incompatible plants can prevent insects that will benefit them from coming to their area.
Vegetables That Don't Like Other Plants
Carrots and dill are not compatible with one another.
Don't plant corn near tomatoes or celery.
Keep eggplant away from fennel.
Tomatoes don't care for dill, potatoes and cabbage, as well as corn.
Plant turnips in a different area of the garden from mustard.
Sweet peppers are foes with fennel, apricot trees and kohlrabi.
Pumpkins are incompatible with potatoes.
Herbs That Don't Like Other Plants
Basil doesn't like rue and sage.
Keep chives away from peas and beans.
Sage is not compatible with onions, cucumbers and rue.
Parsley and mint are not companions.
Dill is not a companion with caraway, tomatoes and carrots.
Flowers That Don't Like Other Plants
French marigolds are not fond of green beans.
Mexican marigolds can have an herbicide effect on cabbage and beans.
Geraniums are not friends with peppers, tomatoes, eggplant, tobacco and the other members of the nightshade family.
Trees That Don't Like Other Plants
Black walnut trees do not provide a beneficial growing environment for most other plants.
Apricot trees are incompatible with sweet peppers.
Some trees are not compatible with their own pollen. For example, many apple trees need another variety of apple pollen in order to set fruit.