We’ve long known that monocultures are susceptible to insect and disease problems, which are often controlled by chemicals. A polyculture (a fancy word for growing a variety of plants in a garden space), on the other hand, is much easier to manage. Plan now to have a diverse balance of plants that will help keep next year’s garden easy to maintain, healthy and – an added bonus – beautiful! 

Step One: Plant Lots of Flowers

Flowers attract pollinators. And many of those pollinators help control the cabbageworms, aphids, tomato hornworms, and other plant eaters that you’d prefer not to have in your garden. For example, common wasps are carnivores that feed on other insects. Parasitoid wasps, especially, make great garden allies!

(L to R) Sweet alyssum, Thai basil, and anise hyssop are beautiful in the garden and attract many pollinators. Syrphid flies (shown on left) are particularly useful as their larvae eat aphids. 

Most herbs do double duty in the garden. (L to R) Lemon balm, cilantro, and dill provide  flavorful leaves for your meals while also attracting parasitoids, such as tachinid flies and tiny wasps that lay eggs in various caterpillars.

Step Two: Mix it Up

Plant flowers in your vegetable beds, and vegetables in your flower beds and borders. Not only will this liven up your garden, it will encourage a diverse biological community: pollinators of many kinds, predator insects, spiders, seed eating birds, and of course plant feeders such as aphids and caterpillars. If you tolerate some early plant damage, beneficial insects will usually come to the rescue.

(L to R) Marigolds are a time-honored vegetable companion; lettuce and sweet alyssum make a good pairing, as alyssum attracts syrphid fly larvae, which prey on aphids that are often found on lettuce; nasturtiums are tasty and beautiful, and can cover the ground between taller plants and shrubs.

(L to R) Garden spiders like to weave their webs between tall plants such as pole beans or sunflowers; kale makes an attractive green accent in the flower garden; Swiss chard leaves are striking wherever they are planted.

Step Three: Remember that Predators Need to Eat

What this means is that you don’t necessarily want to reach for the spray, even if it’s organic, every time you see an aphid or caterpillar. Give the beetle, syrphid fly, and lacewing larvae a chance to find their prey insects. Allow the parasitoid wasps an opportunity to lay their eggs  in tomato hornworms, cabbageworms, or other voracious caterpillars. The eggs will then pupate, giving rise to the next generation of the wasps which will, in turn, help keep future pests under control.

If you see these on your garden plants, you’re in luck! (L to R) These parasitic wasp pupae will hatch and emerge as adults, , which will infect more caterpillars; lady beetle larvae, which look nothing like the adults, eat a lot of aphids; a braconid wasp has laid its eggs in this tomato hornworm. When the eggs hatch inside the caterpillar they pupate (as shown here) and emerge as adult wasps, causing the hornworm to weaken and die.