Companion planting natural pest control

 Companion planting is an organic and natural pest control method that can be used instead of pesticides. Companion planting lets the plants, insects, animals and birds do what comes natural, prey on pests or in some cases simply deter them (It's a natural insecticide)

How does companion planting pest control work.

Companion planting is simply one plant helping another to grow. Growing certain plants close together creates a habitat for beneficial insects that feed on, or deter pests. Close planting can also crowd out weeds and some plants help keep the soil healthy. 


  • Blackfly Aphids eat Broad beans.
  • Ladybirds eat Blackfly aphids.
  • Marigolds attract Ladybirds that eat the Blackfly aphids that would eat the beans.  

Companion planting is that simple.... A natural and organic method of pest control.  More examples and information in this article, including (as shown in the picture) nasturtiums helping protect cabbages from caterpillars. 

Companion planting is an organic and natural pest control method that can be used instead of pesticides that wipe-out every living thing they touch with resultant damage to the environment. Companion planting lets the plants, insects, animals and birds do what comes natural, prey on pests or in some cases simply deter them (natural insecticide).

Ladybird eating Blackfly aphids
Ladybird eating Blackfly aphids
nasturtiums and cabbage companion planting
nasturtiums and cabbage companion planting

 It can be fun it will be rewarding, the food tastes better and it is satisfying knowing you are harvesting safer fruit and vegetables that aren't full of pesticides and herbicides.

Growing the different species of plants I have listed below close together creates habitat for beneficial insects and animals (frogs eat slugs), and deters problem pests and enriches the soil.


Companion planting isn't new, it can be traced back to ancient Roman times and probably all the way back to 2000 BC (that's Before Chemicals) when cottagers, gardeners and farmers used companion planting to deter pests and protect the harvest. And now the Eco worriers have arrived companion planting is back in fashion..... They probably think they invented it.


It all started to go wrong (that's wrong for gardeners) but right for chemical man, when we started to separate crops thus taking the natural predators of pests out of the equation and creating fields and gardens dependent on pesticides or herbicides.

The manufacturers and sellers who are dependent on plant pests ruining harvests, will tell you that companion planting is complicated and doesn't work.

How do I know companion planting does work to control garden pests

I use it, and can assure you companion planting does deter garden pests.

Companion planting isn't complicated and it does work. 

Want to try companion planting for yourself? Try these two experiments; 

  1. Plant marigolds next to your tomato plants this season and see how they deter whitefly. 
  2. Mix nasturtiums with cabbages to help protect cabbages from caterpillars. 

How can I know companion planting works when there's very little scientific proof. Most of the knowledge has been passed down from gardener to gardener over the years and in my case it's been a bit of trial and error as well.  An article I read recently titled "what not to plant together" advised against growing Sunflowers near to anything.  However. I know  that they do amazingly well when planted near corn and actually increase the yield, they can also purify and detoxify soil,     don't ask me how or why,     I don't know,      I just know they do.

common pests I know from experience, that can be stopped or at least deterred by companion planting.

Here are the three examples of common pests that I know for certain from my own experience, can be stopped or at least deterred by companion planting;

  1. CaterpillarsBrassicas are a main food source for caterpillars, they can eat the leaves back to the veins over a couple of days if left unchecked. Planting nasturtiums among them will attract the butterflies to lay most of their eggs in the nasturtiums leaving the cabbages, cauliflowers, sprouts and broccoli for you to eat.
  2. Aphids and greenfly. Marigolds are among the most important companion plants to help control aphids, blackfly and greenfly.  Marigolds work by attracting beneficial insects, like ladybirds and hoverflies, which then feed on the aphids and greenfly.  Marigolds work particularly well in protecting tomatoes. The pungent smells of French marigolds deters whitefly from your tomato plants.  Another benefit of companion planting is certain plants are very effective at attracting bees for pollination.  Marigolds are one of them. 
  3. Carrot fly. Companion plants with a strong scent, like spring onions, chives and garlic planted among  rows of carrots will help keep the carrot fly at bay. 

 I have listed more companion plants and effects below, some are tested, some should work. However, with a bit of practice and trial and error will do something for your garden, and it won't be just adding a bit of colour. 

List of companion plants and their effect

  • Basil for asparagus, peppers, petunias, oregano, also repels mosquitoes. (plant it near to ponds to repel mosquitoes)
  • Borage  works with cucumbers, grapevines, tomatoes, squash, and strawberries.
  • Carrots good companion plants with beans, brussels sprout, cabbage, radish, peas, tomatoes, lettuce, peppers, and leeks. Chives and onions  Rosemary and sage,  helps repel the carrot fly.
  • Catnip Is good planted with eggplant to repel the flea beetles, ants, aphids, cockroaches, Japanese beetles, squash bugs and weevils.
  • Chamomile with cabbage, cucumber and onions.
  • Chives are planted with apple trees, brassicas, carrots, roses, and tomatoes, preventing scab on apple trees and keep aphids and black spot of roses.
  • Chrysanthemum, is a natural insecticide, killing cockroaches, aphids, spider mites, ants and flies.
  • Clover A great green manure plant for lawns, fixing nitrogen into the soil.  Also, attracts many bees and other beneficial insects to the garden, read more about clover
  • Comfrey adds calcium, phosphorous and potassium to the soil, read how to make comfrey fertiliser
  • Coriander  great for repelling aphids and spider mites and attract beneficial insects to your garden.
  • Cucumber Grow with beans, cabbage, dill, eggplant, lettuce, nasturtium, peas, radish, sunflowers, tomato, corn, and onions.
  • Nasturtium  attracts beneficial predators of the cucumber beetle.
  • Dill grows well with cabbage, cucumbers, lettuce, onions, and sweet corn and repels pumpkin bugs.
  • Flax repels the potato beetle. 
  • Garlic  grown near roses repels repel aphids and eliminate black spot.  It will also repel other insects such as Japanese beetles, borers, spider mites, ants and carrot root flies. 
  • Geranium  deter cabbage worms and red spider mites. 
  • Hot peppers in the greenhouse with cucumbers, eggplant, okra, squash, Swiss chard, and tomatoes.
  • Larkspur  will attract some beetles that eat the plant and die.
  • Lavender  attracts many beneficial insects, including bees and is a natural repellent used to keep mosquitoes, ticks and fleas away. 
  • Lettuce Gets along with just about everything, especially beans, beets, brassicas, carrot, onion family, radish and strawberries.
  • Lemon Balm  repels many insects.
  • lucerne attracts beneficial insects including Assassin bugs, Big Eyed bugs, Damsels and Lady Beetles.
  • Marigolds, (but not hybrid varieties) Are great companions, emitting a substance that deters root damaging nematodes, so are really good companions in the veggie garden.  Marigolds also repels the asparagus beetles and tomato worm
  • Mint  grown in containers, deter ants, aphids, cabbage moths, fleas, flea beetles. Parsley doesn't like mint.
  • Nasturtiums  very good companion plant with most vegetables, including cabbages, cauliflower, kale, kohlrabi, radishes, cucumbers and zucchini.  Nasturtiums repel cucumber beetles, wooly aphids, whiteflies, striped pumpkin beetle. They attract lots of beneficial predatory insects.
  • Onions planted with carrots help reduce carrot fly. Also, beneficial with beetroot, brassicas, dill, leeks, strawberries and tomatoes  
  • Oregano grows well with almost everything. It repels the cucumber beetle and cabbage butterfly. 
  • Parsley grows well with asparagus, carrots, chives, dill, onions, roses and, tomatoes. It attracts  beneficial insects. 
  • Peas are companions to beans, carrots, celery, chicory, eggplant, lettuce, parsley, peppers, potato, radish, salvias, spinach, strawberries and, tomatoes. Peas add nitrogen to garden soil.
  • Potatoes grow well with cabbages, carrots, celery, corn, flax, horseradish, marigold, peas, petunia, onion, and marigold. 
  • Pumpkins do well grown with corn, eggplant, marigold, nasturtium, onion family and radishes.
  • Radish  with beans, carrots, chervil, collars, cucumber, grapes, lettuce, melon family, nasturtium, onion family, peas, squash.
  • Rocket is a companion plant for bush beans, beets, carrots, celery, cucumber, dill, lettuce, mint, nasturtium, onion, potato, rosemary, spinach, and thyme. 
  • Rosemary deters bean beetles, cabbage moths and carrot flies. 
  • Sage with rosemary, cabbage, and carrots, it repels cabbage moth, carrot fly, flea beetles and slugs.
  • Squash Companions are beans, corn, cucumbers, melons and pumpkins.  Marigolds and nasturtiums also help deter squash pests.
  • Strawberry will benefit from growing with beans, onions, spinach.
  • Summer Savory Is good with beans and onions, also deters cabbage moths and black aphids.
  • Sunflowers  can help with aphid problems attracting them and keeping them off your other plants. 
  • Tarragon. The scent and taste is disliked by many pests, nearly all vegetables grow well with tarragon.
  • Thyme makes a good companion with cabbage, deterring the cabbage worms.
  • Tomatoes can be planted with asparagus, basil, bean, bee balm, carrot, celery, chive, cucumber, garlic, lettuce, marigold, mint, nasturtium, onion, parsley, pepper, pot marigold, but not potatoes since they can both get blight and contaminate each other.
  • Wormwood  makes a natural insecticide and deters most insects. 


 I haven't tried all the companion plants and effects I have listed, because climate, sun, shade and soil type may limit the plants you can grow in your own garden, so you may want to check some of them out in more detail

I have probably missed a lot of your favourite companions plants, please let me know if you have a tried and tested plant we should know about, or any I have got wrong.  Thanks  mike

Companion planting really is that simple! Try it. 

Try the old tried and tested, Corn, Squash and Bean combination in a small corner of your  garden 

How companion planting works for the wider environment too.

Take a walk in a local wood or a field that has been left to nature, even a disused petrol forecourt, runway or old factory gradually turning back to green. To see natural harmony at work There are bugs that feed the birds, small mammals managing ground growth, and larger mammals including badgers and foxes managing the smaller ones.

Every garden needs birds and wild animals. In addition to being a pleasure to watch, the birds eat greenfly and caterpillars from your plants, badgers frogs and hedgehogs eat slugs and snails.

As the farming countryside becomes more and more hostile to wildlife, our gardens are becoming an increasingly important habitat for wildlife.

This is the environment that can be created in your garden. Making it harmonious for the birds and the bees and other insects and animals and providing free pest control for your plants.

This doesn't mean you have to let your garden become over grown with weeds. They need to be controlled, some are beneficial, but all weeds should be removed before they go to seed. Companion planting can also be used to control weeds by planting non-competing plants closely together to crowd out weed pests.

Companion planting for garden pest control and being Eco friendly need not mean going to extremes. It doesn't mean turning into Eco Worriers.

It does mean caring about our environment, but it also means having a garden we and our family and visitors can enjoy, with patios and decking, etc. or what would be the point.

More about sustainable gardening on my webpage sustainable eco gardening

Bug eat bug - controlling pests with other insects


Read this BBC report on a company set up by Brazilian scientists Diogo Rodrigues Carvalho and Heraldo Negri de Oliveira that is at the forefront of the growing global biological pest control industry - it produces bugs that kill other creepy crawlies, thereby removing the need for chemical pesticides.


Fuelled by growing demand from Brazil's vast agricultural sector, Bug has developed a way to mass produce a tiny wasp called trichogramma that eats caterpillars and other pest insects.


Biological pest control