Attract and Keep Beneficial Insects With an Insectary Garden for Best Pest Control

Yellow dandelion flower with a hoverfly, an important beneficial insect, feeding on it
A hoverfly, and important beneficial insect, is feeding on a dandelion. It's a fly not a bee, though it's hard to tell-- you can tell by its very short antennae, bees have longer ones. Credit: katja from Pixabay

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You may be letting beneficial insects take care of your pest problems. But if you’re having a hard time finding any beneficials, or you have pest problems that are really pushing you to consider extreme measures—and if you like having a garden that takes care of things for you plus gives you nice flowers—there are some things you can do to boost the beneficial insect population in your yard.

Grow an insectary garden—a garden with plants that attract, feed, and house beneficial insects. These can be plants that easily incorporate into your garden or special garden features that do all the work to support these valuable insects. And they can be pretty, too! Here’s what you can do…

Keep the Commute Short for the Bugs

Since most predacious bugs (the beneficial insects) need both pests and flowers to feed on, keep their food sources near each other. If they have to go far between the pests, their nesting sites, and the flowers, they’ll live elsewhere, or not at all. Be sure the best flowers for them are available in your gardens. All in the same landscape, or a close neighbor’s is good.

Create an Insectary Border or Garden

Rather than just planting some good flowers in your landscape, plan a border or bed of flowers that have good sources of nectar and pollen for the beneficials. Also provide habitat for them. See Provide Habitat for the Bees in Your Flower Garden for info, and Grow These Flowers for the Bees, they like mostly the same things.

The border can go along a walkway, at the edge of a lawn, or even instead of a lawn, in or outside of a deer fence. It can be a pretty planting—filled with flowers and grasses, with evergreens that maintain visual structure through the winter.

If you’re having a problem with pests in your vegetable garden mix in some insectary plants to let predatory insects take up residence right alongside the vegetables. See below for ideas.

You can purchase seed blends that are good for an insectary bed. These will help you with the decision-making process. Ask for them at your local nursery, or here are some sources for them online: Johnny’s Seeds, Urban Farmer, and Outside Pride.

But many pretty perennial flowers and annual flowers are perfect for attracting and feeding beneficials, with the benefit of having some cutting flowers to harvest. See some examples in Put Beneficial Insects to Work For You in Your Garden.

Tan and white striped larva on a leaf
Green Lacewing larva cleaning up any remaining aphids on a leaf. Credit: gailhampshire from Cradley, Malvern, U.K, via Wikimedia Commons

Make Your Insectary Fire-Safe

For those living in high fire-risk areas, keep the highest plants less than three times the height of any low branches above them. Use the more water needy plants in the area closest to your house. Use lower water need plants in the outer areas beyond 30 ft. from the house. (It’s important  to keep the area from 0-5 ft. out from structures free of clutter and plant material.) Remove dead material in gardens for fire safety and place it where it can provide habitat for pollinators and predators nearby but in a more fire-safe spot.

Create a Beetle Bank

Predaceous ground beetles seek out and feed on slugs and snails and their eggs, cutworms, and other soil dwelling pests. A beetle bank will provide habitat for them. Yes, it’s an earthen bank for beetles.

A beetle bank is a berm or mound a foot above the surrounding ground that’s planted with native bunch grasses. At least three different grass species is best. It’s elevated because these beetles naturally climb to stay dry. The grasses provide a dry, warm habitat for the insects in winter. In spring and summer the beetles will patrol the grounds for snails, slugs, their eggs, and other soil-dwelling pests, and gobble them up.

Beetle banks can add some visual interest to your yard. It can be pretty with grasses, but you certainly can add some low-growing plants and other perennials to make a pretty asset to your landscape while keeping pests under control.

White daisy with a beetle, a beneficial insect, crawling on it to find nectar and pollen
A beneficial insect, a beetle is searching for nectar and pollen for some of its food needs. Credit: Kai Wenzel on Unsplash

Purchase Spplemental Insects if You Need

You can purchase supplemental insects at various stages of their lives. But this is more appropriate for farm operations. And it may not always be effective.

Put Insectary Plants in Your Vegetable Garden

By interplanting your vegetable garden with good insectary plants you’ll lure in and maintain a beneficial insect population. For example, kale and broccoli are really good at attracting pesky cabbage moths and aphids. But it’s been shown that when the plants are interspersed with helpful flowers, the pest density goes down.

Flowers like sunflowers and echinacea attract many beneficials in the vegetable garden.

And use herbs like dill, cilantro, basil, oregano, thyme, parsley—all are magnets for beneficials.

Plant a Hedgerow

A hedgerow is a planting, like a hedge, of mixed plants, including shrubs and small trees, and ideally natives.

Hedgerows include shrubs to provide permanent year-round habitat for predatory insects. They can also provide a variety of flowers over a season for insects, both pollinators and beneficials, and berries for birds.

Hedgerows provide pollinator and pest control services to orchards and vineyards. And for our homes they can be used to block or enhance views, create microclimates that reduce wind speed, protect against soil erosion, and filter out air-borne dust.

Consider a hedgerow made of a variety of native plants that are deer resistant, drought tolerant, and they can even be fire safe. Surround it with lower growing perennial flowers and self-sowing annual flowers and wildflowers and you’ll create a haven for boosting the beneficial insect population and keeping them there.

The plants in your insectary border and in your beetle bank can be outside of the deer fence and be made of all deer resistant plants.

Remember All the Benefits of an Insectary Garden

With these landscape elements and the plants you can use in them, you’re attracting, feeding, and housing the most helpful insects there are: beneficial insects and pollinators! You’re helping birds, too.

Insects form the base of all terrestrial ecosystems. They feed birds, fish, toads, frogs, snakes, spiders, raccoons, and even bears. They pollinate three quarters of the earth’s plants. Without enough insects, ecosystems will collapse.

So help them and let them do the work they naturally do, and remember their benefits. You reap those benefits when you help them.

For a thorough and enjoyable read about attracting beneficial insects to your landscape and garden Attracting Beneficial Bugs to Your Garden – A Natural Approach to Pest Control, by Jessica Waller is an excellent one!

More Reading About Insects in Your Garden

Feverfew is a nice bouquet filling perennial flower that attracts beneficials

Our Flower Gardens Can Save the Bees shows how our gardens can be very instrumental in boosting populations of all kinds of important pollinators, not just honeybees.

Put Beneficial Insects to work for You in Your Garden–Here’s What They Need From You  Learn about how the beneficial work to rid your garden of pests, and why you can trust them.

Grow These Flowers For the Bees All about the different kinds of bees and the different kinds of flowers that they feed on. And which flowers in your cutting garden are good for the bees.

This Bee-Killing Pesticide May Be in Your Flowers This is an important one. Learn more about what, why, and how they’re used and how they affect insects, including our beneficials, pollinators, and birds.