companion planting for tomatoes

Tomato Companion Plants – Carrots, Marigolds, Petunias, and more…

Tomato companion planting. When ‘companion plants’ are applied throughout the garden, they can be an effective form of pest management, allowing nature to do its’ job.

Companion planting can discourage harmful insects and pests in your garden without harming the beneficial ones.

Many plants have natural substances in their roots, flowers, and leaves that can repel or attract insects and can enhance the growth and flavor of other varieties of plants.

The following are a few companion plants to consider with your tomatoes.

Tomato Plant Companions

Companion plants for tomatoes include Basil, Oregano, Parsley, Carrots, Marigold, Geraniums, Petunias, Borage, any type of Onion or Chives.

By the way, an excellent book on the subject. I purchased it years ago:

Secrets of Companion Planting for Successful Gardening
(view on amzn)

Companion Planting Guide

Borage Flowering Tomato Companion

BORAGE, Borage is a large, sprawling, hairy annual with star-shaped, blue flowers. It is an edible flower (with edible leaves), and is one particularly good companion plant for tomatoes. It is an excellent plant for attracting bees.

When planted nearby, it deters tomato hornworms (a type of caterpillar that will eat the leaves), a voracious eater of tomato plants. Borage is considered a magic bullet of companion plants (predict a square yard for its adult size).

In addition, borage’s sprawling growth habit and large leaves can shade the bases of tomato plants, keeping them cooler and helping to retain moisture in the soil.

Planting Considerations:

“To reap these benefits, simply substitute a borage plant for a tomato every third or fourth plant if you grow them in a line. If you plant tomatoes in cages, plant borage outside of the cage on the side that gets the most sun. In fertile soil and full-sun conditions, borage plants can grow 3 to 4 feet tall. Or you can simply scatter borage seed in your garden and allow plants to come up randomly.”

~ from an article on SFGATE


Marigold and tomato companion planting is a tried and true technique used by gardeners for hundreds of years.

Research studies have indicated that planting marigolds between tomatoes helps protect the tomato plants from harmful root-knot nematodes in the soil.

[ Read: Which are French Marigolds? ]

Basil | Tomato Companion

Basil companion with tomatoes.

Basil is an excellent culinary partner to fresh tomatoes in the kitchen. They are great partners in the garden too… making them one of the many tomato companion plants.

Some say that “basil actually rivals marigolds in the pest repelling category. It is extremely effective in repelling whiteflies, aphids and tomato hookworm. All three of which can spell big trouble for a tomato plant’s health.”

Some reports also suggest that basil may improve the flavor of tomatoes when grown in close proximity.

Oh, and apparently basil detracts mosquitoes to an extent too.

Carrots | Tomato Companion?

Is this one really true? All I can say is that I’ve done this… Growing carrots all around the perimeter of a tomato garden bed. Everything grew okay.

“While many people grow both tomatoes and carrots in the same garden beds, alongside one another, quite successfully, there is no real evidence that either plant does better in the same neighborhood.”

“In fact there is some suggestion that tomato plants can stunt the growth of carrots – which stands to reason if they are grown too close to one another, since the one is a root plant and the other grows above the ground.”

Perhaps the idea came from Louise Riotte, author of the famous book Carrots Love Tomatoes (linked above) who came up with the book title, or maybe her editors suggested it. The idea has taken root, and writers and vegetable growers have perpetuated this idea ever since…


Chives are another tomato companion plant.

Chives help repel pests like aphids, which love to feed on tomatoes. They also repel nematodes, and mites. Another good tomato companion plant.

Petunia | Tomato Companion

Grow petunias as a tomato companion plant.

PETUNIA, an edible flower (with edible leaves), will repel tomato worms.

Not only do petunias attract hummingbirds and butterflies, which are pollinators, but they may help repel tomato worms, beetles and aphids. They are anecdotally recommended in vegetable gardens, and, another good tomato companion plant.

A Few Tips:


Be aware that if you plant carrots too close and under the eventual canopy of the tomato ‘bush’, there won’t be enough light to get good carrots. Ask me how I know… Since then, I’ve planted on the perimeter with success.

Ants Hate Marigolds

There are a few flowers that are known to deter ants from their area. One of the best known is the marigold. Plant a few of these around the borders of your garden or near plants you want really well protected.

“Be careful with marigolds as they can take over. I had to thin them way back so my veggies could breathe. They reseed really well.” said a commenter on Modern Survival Blog


Don’t forget to ‘harden off’ your tomato plants. Basically you’re getting them accustomed to life outside of a greenhouse or your home.


Plant tomatoes DEEP to promote good root growth. In other words don’t be afraid to bury ~25% of the lower trunk with its leaves and all…

Lets hear your success stories (or otherwise) about your tomato plants (and/or tomato companion planting)…

[ Read: Ways to Tie UP your Tomato Plants ]

[ Read: Ways to keep Weeds Down in your Garden ]


  1. This year I planted nasturtiums around my garden fence as well as marigolds, basil, mint and spearmint planted in pots scattered around the ends and sides of the raised beds. Hopefully this help with the insect problems and they provide a lot of nice color.

    1. Romeo Charlie,
      those are also great pollinators for bee’s. gotta keep the bees happy. i planted some sunflowers on the backside of my garden yesterday, i hope they come up. we have had some hummingbird feeders up for a month now but the bees have been swarming them. i would rather have the bees than the hummingbirds.

      1. Hopefully they will keep my bees happy and producing that wonderful honey for our biscuits.

  2. We plant marigolds in small containers and spread them throughout the garden — for voles.
    Nasturtium seed pods and unopened flowers can be dried and used as a substitute for black pepper. Not a direct substitute but nearenuf.

    1. Thanks for the info on the nasturtium I had no idea it was a black pepper substitute (close is better than none) and I like black pepper. Learn something new everyday.

      1. RC,
        Seems there was a black pepper shortage during WW2…
        Was in a book published by our Co-op Extension.
        I’ve tried dehydrating the open flours and leaves, but they lose their peppery flavor when dried. Great when fresh though. At least in a salad.
        Glad I could pass it along. I’m always interested in things like this.

  3. Love gardening! However during my big learning curve from recent experience, I found I could easily grow some types of heirloom vegetables while others commonly sold in nurseries were disease prone and not very productive, under the best conditions I could give them. Most tomato varieties are wiped out by Tomato Yellow Leaf Curl Virus (TYLCV) while Golden Bantam Sweetcorn and Iron Man Spinach were too easy and super productive. It really pays to know beforehand what varieties are best so I am not wasting my time and effort on any duds.

    Can anyone tell me why my potatoes are always small? I have tried clay-loam soil and compost mixed well with potting mix. I plant according to the planting instructions on seed packets and garden guides. Sorry if this seems a bit dumb as I consider myself a bit inexperienced.

    1. Potatos love calcium, check PH on soil and adjust, too much nitrogen can also cause small or no spuds,
      There is a variety of tomato from Johnnys, called Defiant PMR, isnt heirloom but is excellent grower and producer for tough disease conditions, is really the only one i can get decent production from.

      1. Thanks Kula. I first grew potatoes in Bay of Biscay Limestone clay soil to which I added coco peat (acidic coconut coir) which brings my pH 7.6 soil down to just under pH 7 neutral. That frees up a lot more calcium and some magnesium for plants. Yes the soil is rich in nitrogen without adding fertiliser or manure. I was thinking, it may be that I am not watering them enough or soil dries out too quick, while I am at work.
        One thing I do know is that Kestrel potatoes are the least productive of four varieties I tried, under the same conditions. Thanks for your reply.

        1. Lachlan – The only other thing I would add to Kulafarmer’s comment is to plant your potato pieces about 5″ deep and about 12″ between them. I’ve found that too closely planted equals way more small potatoes. I grow Kennebecs and I water them only if no rain after 4 days …..Kulafarmer is correct IMHO, easy on the nitrogen although I side dress once per season with 16-16-16. (And hill them whenever I see 8″ of plant sticking out of the ground)

        2. Thanks Northern Sarge. I’ve noted this down for next time when I will plant Kennebecs as a try.
          So far I’ve tried Red Pontiac (produced okay), White Star (not very productive but great for fries) and Russet (which I haven’t checked on yet). MI Gardener on Youtube was recommending Kennebec as his go-to potato variety. Cheers.

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