If you’re looking for companion planting information, you’ve landed on the right page. The information below has been gleaned from many antique books in my collection and from old copies of way too many magazines to even begin to list.
I do not vouch for any or all of these bits of garden pest protection lore but pass them along to you to try.
I do know many gardeners who swear by any and all of these companion planting techniques to protect your garden from pest problems.
To be honest, I do not use any of these techniques myself and I’m unable to find any scientific proof that they work.
Having said that, I do use commercial techniques that are tested and that do work.
If They Work…
Please understand the effects of each of these garden pest protection plants is very localized (i.e. small area) so if you want to stop ants for example from putting aphids on a tree, you’ll have to surround the tree with petunias. A petunia located a few yards away is ineffective.
A bit of pennyroyal in one part of the garden will not deter pests from entering another. Chives in the herb garden may protect those plants next door but not a yard away. The companion plants have to be companions – kissing cousins so to speak – to be effective.
The research on plant hormones I’ve read suggests that if leaves are touching, there may be a transfer of the hormone and the plant will develop some resistance but if you expect something to work without actual physical contact, there’s no scientific proof it works.
But If You Believe In Companion Planting For Garden Pest Protection:
Here are a few of the tradition combinations for you to use and experiment within your own garden.
- Ants (carrying aphids) then plant pennyroyal, spearmint, southernwood, tansy,
- Aphids plant pennyroyal, spearmint, southernwood, tansy, garlic, chives, coriander, anise, nasturtiums, and petunias.
- Asparagus beetles apparently do not like tomatoes
- Borers dislike garlic, tansy, and onion
- Cabbage maggots are stopped if you plant alternating rows of mint, tomato, rosemary, sage.
- Cabbage moths apparently do not like mint, hyssop, rosemary, southernwood, thyme, sage, wormwood, celery, catnip, and nasturtiums.
- Carrot Fly dislikes rosemary, sage, wormwood, salsify, onions, coriander
- Chinch bugs don’t like soybeans so surround your lawn with them. Right.
- Colorado Potato Beetle doesn’t like green beans (me neither), horseradish, dead nettle, and flax.
- Cucumber Beetle is repelled by radish and tansy
- Cutworms are driven to distraction by tansy
- Eelworms are repelled by big stinky marigolds
- Flea beetle wormwood, mint, catnip, tomatoes
- Fruit tree moths of all sorts don’t like southernwood
- Groundhogs castor beans and human urine (human urine only works if you urinate down their holes) although the latter is enhanced by imbibing products made from hops
- Japanese Beetles garlic, larkspur/delphiniums, tansy, rue, geraniums
- Leafhopper petunias and geraniums
- Mexican bean beetle marigold, potatoes, rosemary, summer savory, and petunias
- Mice don’t like mint (mice hate fresh breath)
- Mites are repelled by onion, garlic, and chives
- Moles don’t like spurge, castor plants and castor oil, fritillaria bulbs
- Nematodes stinky marigolds, salvia, dahlia, calendula, asparagus
- Plum curculio is supposedly repelled by garlic – don’t ask me how you get it into the tree but I’ve read this more than once. (maybe all copying from one source)
- Rabbits don’t like onions or the onion family (garlic/chives etc)
- Rose chafer geraniums, petunia and onion family
- Slugs don’t like rosemary, wormwood and that might be the only two plants they won’t’ eat
- Squash bug don’t like tansy and nasturtiums
- Pumpkin beetle doesn’t like nasturtiums (and nasturtiums don’t like it either)
- Tomato hornworm is deterred by borage, marigolds, and basil.
- Whitefly won’t go near nasturtiums, marigolds, nicandra
- Wireworms apparently don’t like mustard and buckwheat.
My Take On Companion Planting
Companion planting is a mixed bag of garden information with some gardeners saying there are effects from these techniques and others equally adamant that there are few if any measurable effects other than wishful thinking.
My own sense of it is that when the hordes of locusts or Japanese beetles come out of the sky, planting a marigold next to a tomato isn’t going to help much under this level of problem.
And for the record, the only thing I’ve read about marigolds (that works) is that the big old-fashioned ones secrete a hormone from their roots that “deters” the root knot nematode. But the fragrance doesn’t do a darn thing.
Not having seen real research other than this, I consider companion planting mostly a waste of time unless it makes you feel better.