Growing Tomatoes with Companion Plants

19 Nov

growing tomatoes

Basil and tomatoes both flourish when
they are grown together

Most of us value good companions in life; but not everyone realizes that plants also appreciate good companions. For some it will be a revelation to discover that like humans, plants also need companions that will shelter them, support them, and help them survive by providing nutrients, often attracting insects that will pollinate their companions, and even chase away bugs that might be detrimental.

Companion planting is nothing new; people have been doing it for centuries. But for a long time a lot of people weren’t doing it, probably because of a surge in chemical fertilizers and insect sprays which were the norm worldwide during the 20th century.

As an increasing number of people embrace the need to “go green”, companion planting is gaining popularity again, and very fast.

So when you’re growing tomatoes, which vegetables, herbs, flowers and weeds do they prefer to be planted with?

The Tomato’s Favourite Companions

Basil is regarded as one of the tomato plant’s best companions. An amazing herb that deters aphids, flies, mosquitoes, whitefly and other pests, it may also be used to make a spray that will get rid of fungus, mildew and scale. Many people also maintain that the flavour of basil is absorbed by the tomatoes that grow near it.

When growing tomatoes, here are some of the other plants that the tomato thrives with:

  • Asparagus, which tomato plants are able to protect from the asparagus beetle by producing solanine, a type of glycoalkaloid poison found in plants of the nightshade family (including tomatoes). Tomatoes also minimise the weeds that may stunt the growth of asparagus. And in reciprocation, a chemical found in asparagus protects tomatoes from nematodes.
  • Carrots, which stunt the growth of some plants, like cabbages, potatoes, broccoli and cauliflower, but thrive with tomatoes.
  • Celery that has an antiseptic agent and gets rid of micro-organisms. One theory is that if you grow celery in a circle, the loosely interwoven roots will attract earthworms and soil microbes.
  • Garlic bulbs planted between tomato plants protects them from red spider. See also Onion family.
  • Marigolds that release thiopene, which is a proven nematode repellent, into the soil.
  • Nasturtiums, a hugely successful “trap” crop for whitefly, aphids and red spider.
  • Onion family vegetables, including chives that act as a strong deterrent against insects (including aphids) and mildew.
  • Parsley, which has an uncanny ability to boost the growth of tomatoes.
  • Stinging nettles that add nitrogen to the soil and are proven to improve the quality of tomatoes growing nearby.
  • Yarrow, recognized as an excellent fertiliser.

It is also worth noting that roses and tomatoes are good companion plants, largely because tomatoes are able to protect roses against developing black spot.

Plants that tomatoes don’t like to be planted with or close to are:

  • Apricot trees, because excretions from the roots of tomatoes tend to inhibit their growth.
  • Brassicas, including broccoli, cabbage of all sorts, cauliflower, and kohlrabi. An exception is collards that benefit from being planted with tomato plants because the tomatoes seem to dispel flea beetles that are a major collard pest.
  • Corn, because the fruit-worm that attacks tomatoes is exactly the same as the earworm that attacks corn.
  • Fennel that stunts the growth of tomatoes (and most other vegetables).
  • Kohlrabi that also has a detrimental effect on the growth of tomatoes.
  • Potatoes, because perhaps oddly, they make them more susceptible to potato blight.

When growing tomatoes, also be aware that not all the tomatoes favourite companions will grow happily with other “companions”. For instance, while sage and cucumber are both great companion plants, they don’t thrive together at all!

Check out our book How To Grow Juicy Tasty Tomatoes for more information about growing tomatoes.