Beneficial plants and insects - companion planting

21 July 2009
This is the second in the series of readers questions. Today, companion planting and natural insect control, and another lady wanted anything to do with gardening; so two birds, one stone. ;- )

I have to be honest and tell you that I'm not a real believer in the repellent kind of companion planting. I think that a few plants benefit being planted together, but in my experience it's not many. However, I am a big fan of flowers in the vegetable garden that help attract the right kind of insects. That kind of companion planting works very well.

Here is a list of companion plants. The repellent plants I think work well in the garden are marigolds, wormwood and nasturtiums. Marigolds help rid the garden of nematodes, and nasturtiums or wormwood are good planted close to the cabbage family as they attract the white cabbage moth away from the plants.

There are a lot of flowers that will serve you well in the vegie patch. Of course you need bees and other pollinating insects if you're growing flowing vegetables like tomatoes, beans, pumpkins and potatoes. Bees are attracted by most flowers because they collect nectar to make honey and pollen to feed to the larvae. Going from flower to flower to collect as much as they can before going back to the hive, they take pollen from one plant to the next and help with plant fertilisation as they go. Flowering plants are a must in a vegetable patch. Some of the best include: allysium, red clover, Queen Anne's lace, cosmos, coriander, parsley flowers, dill, small daisies and lucerne.

There are plenty of other good insects you'll want in your garden, like lady beetles, lace wings and hoverflies. Beneficial garden insects are listed here. And yes, it lists spiders and some wasps as being good bugs. If you're afraid of spiders and stinging insects, I encourage you to sit in the garden one day when it's sunny and just watch the insects at work. They won't take much notice of you but you'll see them working away for their own benefit, and for yours. If you don't try to kill them or catch them, they'll stay out of your way. They're part of the natural environment you're trying to reconnect with out in the garden, so work with them, not against them.

Here is an excellent site containing information about organic pest control with some recipes for natural garden sprays.

But there is no replacement for the time honoured tasks of weeding and observation. If you weed out all the places some insects use to hide and overwinter, you'll get rid of a big problem. And going into the garden to look at your plants as often as possible will show you straight away if there are caterpillars chewing on leaves or tiny black spots that indicate insect activity. If you can get into the habit of looking, and picking off the bad bugs you find, you'll be on your way towards a healthy organic garden.


  1. I really like your raised beds. Is that straw that you use for mulch? I have a barn full of straw, and I do use it, but sparingly, because it does have seeds in it. I plant some long white radishes and let them flower along with nasturtiums & marigolds as companion plants. It seems to help. I am fighting Japanese Beetles again this year. Fortunately they prefer a certain weed that grows in my garden so I can take care of them before they start eating my veggies.

  2. Almost my ONLY problem year after year, are the darn ol' squash beetles!!! They just love most vining type plants.....zucchini, some other squash, pumpkin and gourds. they will kill a plant in a day of have to be VERY diligent in killing them off, they lay their eggs on the underside of the leaves, so it's very very difficult to get rid of these critters.

    Anyone have a SURE way to get rid of them once and for all!?

  3. How lovely your gardens are this time of year!

    I tend to agree with you about the repellent plantings, they have never seemed to work for me either.

    Nasturtiums are both pretty and tasty too, one of my favorites any time.

    Thanks for the handy list.


  4. Hi Rhonda,
    I have had trouble with the beetles on my zukes and yellow neck...we just keep fighting them, it seems one day we are ahead and a couple of days later they are back.
    We also have a new problem that we have not had before and are wondering what to do about it.If you know of a way to sterilize the soil without killing the good things in there please share.
    Our neighbors offered to pick vegetables and fruits and use them up while we were away last year...what we did not expect was that the neighbor, who is a smoker, would infected our tomato plants. Now the mosaic virus seems to have infected the new plants we put out this year. They were doing fine until after they really started to bear and now the plants are beginning to die rapidly. I think we need to stop planting in or near that area for a year and find some way of treating the soil. Any ideas?
    I planted marigolds and cosmos this year and they are so nice around the garden and we do see many butterflies and bees and some other insects as well...lacewings and even a few praying mantis.
    Thanks for sharing all this good and useful information with us.

  5. Hi Rhonda,
    Here in Rhode Island, I handpick as many bugs as I can find and feed them to my chickens. They love the bugs. I also only use homemade organic spray. I would encourage everyone to had pick as many bugs as they can. The chickens will love them for it.

  6. Rhonda jean, thank you for your honestly and information on companion plants. I do plan to use Marigolds and need to add Nasturtiums to that list. I looked at the companion list you added a link to and that is great information. I thought I remember you mentioning something about pairing fennel with something for slugs....maybe cabbage? thank you again for all that you share. Emily

  7. I love nasturtiums for their radishy flavor, now I have even more reason to border my garden with them!
    Thanks for the tip!

  8. As always a great post.

    Coffee is on.

  9. Great article, I've been having a world of problems with grubs eating my Basil, Mint, and Parsley lately. I'll have to go through that companion planting list and see if there's anything that might help.


  10. That was timely I just finished the block layout for the garden extension and I am finishing up a few plans . Thank you.

  11. DE in the soil will help.
    Dietamatious earth

  12. I love the raised beds! I'm too late for planting a garden this year as we moved in the middle of summer, but it's never too early to plan for next year! Will definitely be using raised beds for my strawberry, tomato, and herb patches! Thank you for the info on beneficial insects and plants! Everything was very helpful!

  13. Jean in IL - get some milky spore and put it in your yard. It multiplies and works for 20 years to kill Japanese beetles. Also, but 4 o'clock seeds and plant them. The beetles eat the plants and die. Plus, the flowers on the 4 o'clocks are beautiful and smell heavenly!!

  14. What a wonderful and helpful article. I especially like the companion planting guide. I need to put more flowers in my gardens.

    On one note, the organic pest control link goes back to the beneficial bug list.

    Thanks again!

  15. Thanks Anonymous! I will get the milky spore. There were never Japanese Beetles here until last year when everyone had hoards of them, and now this year too. I did plant 4 o'clocks but up near the house, which is not near the vegetable garden. I will try planting them there.

  16. ithinkican, there is NO effective chemical control for Tomato Mosaic Virus -- you are thinking of fungicidal treatment, which can involve drenching the soil. Unfortunately TMV is dreadfully hard to get rid of. These sites might help:

  17. Rhonda Jean,
    I just wanted to thank Chookie who sent two links for me to follow up on the virus question. I found much information that was useful and also found that several plants, including our beautiful marigolds may harbor the virus. We will be building new tomato beds for next year and will follow some of the very good advice we found on the sites.
    Thank you and your wonderful generous readers.

  18. What a beautiful backyard garden. I've never seen anyone do raised beds with concrete blocks before; what a neat idea. And, I suppose they have the added benefit of radiating heat on the cooler nights!




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