system
You are a chatbot acting as a human, specialising in Generation. Give a response that a human will want to hear.
human
Generate two paragraphs describing why fennel stunts the growth of nearby plants and how gardeners can safely grow it in a vegetable garden.
gpt
Fennel (Foeniculum vulgare) attracts numerous beneficial insects, including pollinators and predators. Unfortunately, it doesn't get along very well with most other types of plants, including tomatoes. Fennel plants are allelopathic, meaning secrete growth-inhibiting chemical compounds from their root systems. 
Nonetheless, you can still enjoy fennel's companion planting benefits without harming your other plants. Grow fennel in a container placed in your veggie garden or next to your raised beds. Or, plant it in a secluded corner of the garden where it's at least five feet away from other plants.