Companion planting flowers in the vegetable garden

By Dorothy Dobbie

Nasturtium.

Tansy.

There are several reasons to plant flowers in the vegetable garden, and the reason may dictate what to plant. Flowers in the vegetable garden are a pleasure to look at and many produce chemicals that most bugs hate. Others act as attractive lures to pollinators and other beneficial insects.

Mexican marigolds (Tagetes patula), for example, repel cabbage worms, aphids, whiteflies, slugs, and certain nematodes. This stubby little yellow and orange plant, deters harmful nematodes in the soil, but to benefit you need at least one season for roots to do the work needed under the surface.

Mexican marigolds are reported to keep rabbits out of the garden! Rabbits also stay away from daffodils, cleome, monarda, and snapdragons. A border of sweet alyssum may just be enough to keep them out of the cabbage patch. As a rule, plants that have tough leaves, a strong odour, furry or prickly stems or a milky sap are avoided by deer and rabbits both.

However, there is always the gourmet critter out there that ignores the rules and of course, if they are hungry enough, they will eat anything they can.

The list of lovely flowering annuals that deter insects of all kinds is quite long and includes chrysanthemum, catnip, geranium, and nasturtiums.

Cabbage worms are a bane to most gardeners. You probably know them best as little white butterflies with a couple of black spots on each wing. They go after all the brassica plants including broccoli and cauliflower. Nasturtiums act as a trap that attracts the butterflies to lay their eggs there instead of on the cabbages. Try planting thyme, tansy, or marigolds to keep cabbage worms at bay. Yarrow will attract good bugs that can do some of the fighting for you. Parasitic wasps, for example, lay their eggs in the larvae of cabbage butterflies and destroy them from the inside out.

Daffodils.

Cosmos.

Geraniums.

Yarrow.

Good bugs include not only parasitic wasps, but ladybugs, lacewings, soldier beetles (mainly in the east), damsel flies, and dragonflies to name just some of our garden friends. Big eyed bugs occur widely in Canada and are great insect predators. There are about 800 species of ground beetles in Canada, many of which eat slugs. Amaranth plants (love lies bleeding) will attract ground beetles.

Carrot family plants are attractive to parasitic wasps and include Queen Anne’s lace and cilantro.

Asters attract predator insects such as ladybug and soldier beetles, as do goldenrods and zinnia. Soldier beetles love aphids. As larvae, they feed on other harmful insect eggs.

Blanket flower (Gaillardia), cosmos, yarrow, sunflower, verbena bonariensis, lantana, lilac vervain, and tansy all attract beneficial insects. Pretty cosmos and bachelor buttons will attract pollinators, parasitic wasps, bees, and butterflies to the garden.

There are also some worms you may or may not want to attract. I personally don’t mind a few tomato hornworms because I love their sphinx moths that look like hummingbirds among my flowers at dusk, but if you are a serious tomato grower, they may be the bane of your existence. Try planting borage with your tomato plants. This herb bears the prettiest little star-shaped flowers that are often used as garnish on gourmet plates. Basil is another useful deterrent and good old marigold is another ally.

Finally, you need to know how to battle the dreaded potato bug, the striped menace to all members of the nightshade family, including petunias, peppers, and tomatoes. Catnip, cilantro, tansy and marigolds are all good deterrents.

If you live anywhere in the vicinity of canola crops, be prepared for annual infestations of flea beetles which will attack a wide range of garden vegetables and other flowers. Nasturtiums can act as an attractant to lure flea beetles away from your prize plants and they adore cleome (sadly for cleome lovers) as well as stocks, alyssum, and anemone. Mint, catnip, and basil are unattractive to this nimble little black devil, which is named flea beetle for its ability to jump.

Snapdragon.

Cleome.

Sunflower.

Monarda.

Blanket flower.

Borage.

Other benefits to having flowers in the veggie plot? They can help keep weeds down. Sweet peas and lupines are leguminous and can help capture nitrogen in the soil in a form that vegetables and other plants can use. Flowers such as chamomile act as “nurse” plants and can encourage the development of oil content while helping to improve pest resistance and increase yield. Chamomile is an insect deterrent, an antibacterial and makes a health-giving tea.

Finally, growing lovely flowers, especially annuals, in the veggie garden is a great place to collect morning bouquets to brighten your days indoors or adorn an outdoor eating area.