Companion Planting: Tomatoes

Did you know that certain plants actually get along better with each other than others? Some plants support each others growth, while others are best kept far apart. Just like people! Read on to learn more about what plants bring out the best in your tomatoes, and which ones will actually hinder them.

Tomato Friends

Carrots and tomatoes complement eachothers growth habits. Carrots like cooler temps and tomatoes will provide them with shade. Lettuce can also be a good companion for tomatoes for this reason. With both lettuce and carrots, they will grow better planted early (and harvested soon after tomatoes go in) or late (and harvested after tomatoes are done) in the season. Amaranth helps to repel insects. Basil and borage are also said to repel insects and improve the flavor and vigor of tomato plants. I like to plant at least one basil for every tomato plant and a couple of borage plants in a large tomato bed. Garlic repels red spider mites. Marigolds repel a plethora of insects, including slugs and nematodes. Mint is an excellent garden companion, repelling many insects, but it can also be invasive. Grow in pots to keep the roots from spreading, and cut back frequently to keep it from dropping seeds. Parsley attracts hoverflies, which feed on tomato pests. Dill can be be grown with tomatoes to enhance flavor and growth when young, but once dill matures it inhibits tomato growth and should be pulled out. Nasturtium is also good at repelling pests and may help prevent fungal disease. Asparagus and tomatoes have a mutually beneficial relationship as asparagus produces a chemical that kills nematodes and tomatoes repel the asparagus beetle. Tomatoes will repel insects that feed on gooseberry plants and will protect roses from black spot. Other plants that are benficial to tomatoes: calendula, celery, chives, cosmos, cucumber, lemon balm (can be invasive), onions, nettle, squash, and thyme (I love using thyme as a ground cover or living mulch all over the garden).

This post contains affiliate links.

Tomato Foes

Do not plant tomatoes near black walnut trees, they produce an alleopathic chemical and most plants do not like them. Fennel is like this too, I pretty much stick to growing fennel in pots. Remember to keep mature dill away. Members of the brassica family (kale, cabbage, broccoli, Brussels sprouts, collards, kale, kohlrabi, turnips, and rutabagas) will inhibit tomato growth. Tomato is a nightshade plant, so avoid planting with other nightshades such as peppers, eggplants, and potatoes, as they are prone to many of the same pests and diseases. In fact, avoid planting nightshade vegetables in the same bed for three years if possible. If working with a small space and there is not a lot of opportunity for rotation, it would be better to pick a bed to grow the nightshades in and then rest it for three years rather than to grow one nightshade in the same bed every year. Corn and tomatoes share a common enemy: the corn earworm or tomato fruitworm.

How I Plant My Tomatoes

I have planted my tomatoes in triangles rather than straight lines (this fits more in a row) and I have also planted rows on either side of a cattle panel. When they are in triangles I use bamboo stakes to tie them up to, against a cattle panel I can tie them directly to it for support. I use old strips of cut up t-shirt to tie up my tomatoes rather than plastic gardening tape. The cattle panel is the easier way maintenance wise, but I prefer the way the bamboo way looks. Right next to my tomatoes I plant marigolds, basil, nasturtiums, and lettuce. At either end of the bed I plant garlic and onions, and more flowers. I will plant one or two borage plants throughout the bed. Sometimes I grow cucumbers in the same bed as tomatoes as well. I will stick other herbs and flowers in (chives, parsley, calendula and zinnias are my favorites) as space allows.

So this year, instead of planting just tomatoes, invite a few of their favorite friends to the party and observe how the pest resistance, growth, and flavor can all be enhanced. Do you use companion planting? Did I miss a favorite companion of yours? Please let me know in the comments!