Pest Control with Plants

As I talk to folks about my garden, many are surprised to hear that I use plants to control pests to keep the garden organic. My biggest helpers are marigolds, nasturtiums, and rosemary. Some of these repel harmful critters and bugs, while others attract the right kind of bugs.

My research tells me that marigolds repel and offend a host of destructive insects and rabbits too. I've been told mosquitoes don't like them either. This year I started my own from seed because I was disappointed by the lack of choice at the garden center in the past. I selected two varieties for their small size, color, and uniqueness from the typical marigold on the street. I have a few plants spaced throughout my raised beds and added more as a boarder plant near my tomatoes.

Lemon Gem Marigold

Lemon Gem Marigold

Lemon Drop Dwarf Marigold

Nasturtiums are actually edible flowers and are sometimes served in salads. I use the plants primarily to confuse bugs, which are attracted to the nasturtiums. They also work to fight off fight off wooly aphids, whiteflies, squash bugs, and cucumber beetles. The flowers act as a trap for aphids, which is why I tend to leave mine to the bugs instead of eating them! I've been told the bunny rabbits don't like these either. I started mine from seed this year so that I could choose interesting varieties that don't grow too large (since I need space in the raised beds for the veggies!). I likely started my seeds too early outdoors and didn't have much luck with the first set - only two plants survived. But I started more seeds and hope to use the plants as a boarder in new places other than the raised beds since they are quite pretty.

Empress of India nasturtium (from last year)

Cherry Rose Jewel Nasturtium

Rosemary is mainly used as a companion plant to help feed my cabbage, beans, carrots, but it also deters cabbage moths, bean beetles, and carrot flies. I have two large thriving plants that I wintered in my cold frame. I chopped off a huge amount of the growth from over the winter and started several new plants from the clippings. We used the considerable clippings in the kitchen too, of course. The plants will continue to grow and can turn in a large bush in this climate.

rosemary clippings

As I was looking into the specifics of my helpers, I realized that there are other plants in the garden doing the same thing. I've been planting basil along side my tomatoes as a companion plant which feed nutrients to one another. I just learned that the oils in basil repel thrips, flies and mosquitoes. It's a good thing I planted LOTS of basil!

Just yesterday I planted catnip for Mica and Molly and now I'm reading that catnip plants repel just about everything. It can be used to keep away flea beetles, aphids, Japanese beetles, squash bugs, ants, and weevils. AND dried sachets of dried catnip will help deter the annual parade of ants that invade my kitchen. Can't wait to try that!

Dill repels aphids and spider mites, which I have planted near my basil and tomatoes. But now I see that its also ATTRACTS hoverflies and predatory wasps, and its foliage is used as food by swallowtail butterfly caterpillars. I guess we can't win them all.

Lavender is a favorite among many beneficial insects and also repels fleas and moths. It grows in huge beautiful plants, nearly bushes, in our climate. I have a one well established plant fighting its way out from the ivy in our front yard, but I've been struggling to find the right variety to do well in the back. I'll keep trying!

I have a patch of garlic, which I'm hoping I can soon harvest. It deters codling moths, Japanese beetles, root maggots, snails, and carrot root fly. I don't know what these guys are, but they must be bad!