Companion planting is not something that I’ve practiced much in the past, but now that I have a more permanent situation for gardening, I’m going to make an effort to plant things together that will benefit one another, and to keep things away from each other that will cause trouble.
Since I haven’t been able to start my vegetable patch quite yet, so far I have just planted companions for my fruit trees and shrubs. I’ve tucked fennel, chamomile, thyme, tarragon, oregano, mint, garlic, yarrow, and daffodils into the corners around my cherry and apple tree and the spots where I will be planting a plum and a pear tree in the next month or two. These companion plants can freely spread and create a ground cover outside of the spaces where I will be standing and setting up my ladder to care for and harvest the fruit trees, and they all have their uses as food, medicine, and beauty, as well as benefits for my trees.
Some say that “fennel doesn’t have any friends,” but that actually isn’t true. Fennel doesn’t get along with other annuals, because the plant contains ethanol, which will inhibit the germination and growth of other small plants. In other words, fennel has developed an edge to beat out its competitors — but it can still make a good companion to other plants.
While I don’t want to plant fennel in my vegetable beds, it can be planted in other places, like the landscape or orchard, where it will suppress weeds, attract beneficial insects, and repel pests. It’s a common plant used in an apple tree “guild” — a companion planting centered around an apple tree. Fennel’s friends include ladybugs, hoverflies (aka “sweat bees”) and parasitic wasps. These insects are mortal enemies of aphids, leafrollers, leafminers, and codling moths, which are all common apple tree pests. Plus, aphids apparently hate the fennel itself. My other trees will also benefit from protection from some of these same pests, as will the other plants in my garden.
Those parasitic wasps attracted to the fennel will also likely reduce my garden’s population of cabbage moths, which are always a problem for my brassicas. So fennel is a good, if not friend, then let’s say…distant relation, for the vegetable patch, too.