Tomatoes are one of the most rewarding plants to have in the garden. They are fairly easy to grow making them great for beginning gardeners, while still offering a challenge to established green thumbs. If all goes well, they produce gorgeous fruit (vegetables? both?) that can be eaten in sandwiches, thrown on pasta, stuffed, pickled, fried, roasted, broiled, marinated, and so much more. (Tomato jam, anyone?) However before you start your cooking and eating, you have to get your plants to grow.

One of the best ways to make sure your tomato plants thrive is to put them in the ground surrounded by companion plants that can help them by offering soil enrichment or pest deterrence. It also helps to keep them far, far away from plants that can rob them of nutrients, block their sun, attract disease, or otherwise harm them.

Here are some plants to avoid with tomatoes (and a few good companions):

Brassicas
Cabbage, broccoli, cauliflower, kale, Brussels sprouts, and kohlrabi can all stunt the growth of your tomato plant, because they out-compete them for the same nutrients.

Corn
Corn and tomatoes may be great together in cooking, but they should not be planted together because they both attract the same sort of pests and fungal infections. Putting the two next to each other in a garden makes them doubly attractive to bugs.

Fennel

Like brassicas, fennel will inhibit the growth of tomatoes. In fact, fennel isn’t a good companion for most garden vegetables and should be grown in its own little patch or pot.

Dill
While many herbs grow well with tomatoes, dill is the exception. Young dill does well, but when it gets mature and ready to seed, dill plants can inhibit tomato plant growth.

Potatoes
Tomatoes and potatoes are both members of the nightshade family, which means they need the same nutrients to grow. That means they will be in competition with each other, which doesn’t benefit either and can make them susceptible to the same diseases.

Eggplant

Like potatoes, eggplant are in the nightshade family making them competitors. Eggplant are also susceptible to blight, which makes tomatoes planted nearby more susceptible to blight, too.

And now for the plants that help tomatoes thrive:

Asparagus
Asparagus and tomatoes are the dynamic duo of the garden. Tomatoes repel obnoxious asparagus beetles while asparagus keeps away nematodes in the soil, which can harm tomatoes.

Chives
Not only are chives a delicious herb to have in the garden, but they repel aphids, nematodes, and mites, making them excellent companion plants for keeping your tomatoes safe.

Lettuce

Plant lettuce near tomato plants to create ground cover that will help keep the soil moist and cut down on weeds (and weeding). In return, the shade from tomato plants can help provide some cover for the lettuce and stop it from bolting.

Marigolds
These bright blooms not only attract bees and ladybugs, which are good for a garden, but they also keep away aphids, slugs, tomato worms, and snails that love to munch on tomatoes. These helpful plants also help keep soil healthy for tomatoes.