Plants to Avoid Growing Near Tomatoes

healthy tomatoes growing on vines in garden
Loading... 9 view(s)
Plants to Avoid Growing Near Tomatoes

Your Tomatoes’ Worst Enemies: Plants That Compete with Your Tomatoes in the Garden

Last time we identified great companion plants for your tomato patch. Now we’d like to mention a few types of plants that, while they might not actually have a vendetta against your tomatoes, certainly won’t do them any good.

Though there may be many reasons to separate two particular types of plants in the garden, two stand out when it comes to tomatoes:

  • The plants are competing for nutrients and other resources.
  • The plants attract the same pests or diseases.

Here are some plants generally considered to be unfriendly in the tomato patch:


Both corn and tomatoes attract the same predatory worm, so when they are placed together, your crops can become a feast for undesirables.


Like corn, the potato shares a potential problem with tomatoes. In this case, it’s both early and late blight — a disease to which both potato and tomato are very prone. Keep them apart to prevent blight from getting a foothold in your garden.

The Brassica Family

Many gardeners report that their cabbage, cauliflower, broccoli, Brussels sprouts, and/or kohlrabi do just fine near tomatoes, but the conventional wisdom is that this family — the Brassicas — should be grown apart from tomatoes. Several reasons are given for this: Brassicas share a tendency toward the same fungal diseases as tomatoes, so it is unwise to concentrate them all in one place. Also, the Brassicas are heavy feeders, and may compete with your tomatoes for resources.


More evidence of the Brassica family’s incompatibility with tomatoes: rosemary grows beautifully with cabbage, broccoli, and all the rest, but is not a friend to tomatoes.


Many herbs make splendid companions to tomatoes, but fennel has been found to inhibit its growth. Grow this beautiful licorice-scented plant elsewhere in the sunny garden.

Black Walnut Tree

You probably had no intention of planting your tomatoes around a walnut tree, but just to be safe, we thought we’d mention it: Black Walnut releases a soil-borne chemical that really hampers the growth of tomato plants.


These are plants that, when planted beside tomatoes, can do both harm and good.


Young dill plants are fine friends to tomatoes, but when they grow up, they can stunt their neighbors’ growth. Rather than worry about them “turning” on their old friends, best to just put them elsewhere.


Yes, carrot! We have all heard that carrots love tomatoes, but do tomatoes really love them back? Tomato plants can stunt the growth of the carrot root, although it won’t affect the flavor. So, the choice is yours: they are good pest-fighting friends together, but your carrots may not reach their full size potential when grown with tomatoes.