Fennel emits chemicals into the soil as it develops, which can restrict the growth of surrounding herbs and vegetables.
Cabbage loopers also prey on brassicas. Strawberries cultivated in conjunction with brassica plants are much more prone to develop cabbage looper.
Sage has an effect on the growth and productivity of neighbouring cucumber vines. Growing sage and cucumbers in the same region requires distinct water requirements.
Onion and garlic appear to hinder asparagus growth, and their big bulbs can suffocate asparagus crowns.
Tomatoes and maize are both susceptible to corn earworms, and planting these plants together can make pests spread more easily.
Dill and carrot are so closely related that they could cross-pollinate and produce low-quality hybrid seeds.
Growing potatoes and tomatoes together allows pests to migrate quickly from plant to plant, causing havoc on your edible crops and stripping your plants of leaves.