Marigolds as Vegetable Companion Plants - Planters Place

Marigolds are not just pretty in flower beds, they have a job in the vegetable garden as beneficial companion plants. No, that doesn’t mean they make good company and keep the veggies company. They can help lessen the damage done to vegetables by certain pests.

I’ve planted marigolds around my tomatoes for over a decade now, out of habit or tradition, I’m not sure which. I had heard long ago that marigold exuded a chemical from their roots that deterred soil nematodes. A quick Google search says this could be one of those unresearched facts that only experienced gardeners can speak to. Well, I consider myself the latter: My tomatoes always did well with marigolds nearby and have faltered without them at times.

Deterring Pests 

Members of a new online gardening group I just joined had their own opinions about the efficacy of marigolds as companion plants. I had posted a photo of my insect barrier protecting radishes from flea beetles, and one member weighed in with the idea of planting marigolds as a companion plant to deter the beetles. She said that planting marigolds in the area would also keep flea beetles away, which I hadn’t heard. A week later I noticed my garden neighbor had just planted marigolds around her sown crop of arugula, another flea beetle favorite. As you can see in the accompanying photo, it looks like she planted them just in time, too. Flea beetles had had a feast when the seedlings just emerged.

I found a wonderful resource from Cornell Cooperative Extension, a worksheet simply called Companion Planting. In it, the extension team outlines what other pests marigolds deter, including my other nemeses the aphid, cabbage maggot, cucumber beetle, squash bug and rabbit! It looks like I will be planting marigolds pretty much everywhere in my garden this year.

The Companion Planting worksheet also lists a ton of other companion plantings that benefit the vegetable garden, such as interplanting beans with carrots, cauliflower and beets. And what do you know, they also suggest planting marigolds around tomatoes. I knew I heard that suggestion somewhere.