When it comes to choosing the ideal plants to line your garden, you want to be a good host to your friendly neighborhood beneficial insects—think: ladybugs, lacewings, and ground beetles. To get the energy they need to search for their prey or to reproduce, many of these critters need nectar for carbohydrates and pollen for protein, and certain flowers are much better sources of both. You'll also want to select plants that will serve as shelter to help those beneficial insects thrive. Making the right plant choices means these happy insects will return the favor by pollinating your fruit and vegetable garden, increasing your yields. The following plants are all good picks, but be sure to check their invasive potential where you live, as a few of them may become weedy in certain climates.
This beautiful blue wildflower has extrafloral nectaries, which means the plant's leaves release nectar even when the flowers are not blooming. Research in Germany has found that Bachelor Button nectar has a very high sugar content of 75 percent. This nectar is highly attractive to flower flies, ladybugs, lacewings, and beneficial wasps. Sow seeds directly in the garden in fall or early spring and these plants usually reseed energetically.
Designing With Annuals And Perennials is super easy with this low-growing annual that makes a lovely white, highly fragrant edging for flower beds or a fast-growing, beneficials-attracting, weed-smothering ground-cover to interplant in vegetable beds. Numerous studies have confirmed that Sweet Alyssum is highly attractive to aphid-eating flower flies. You can start with seeds or buy bedding plants for earlier flowering.
This annual herb has bright blue clusters of edible, cucumber-flavored flowers. Studies in Switzerland have shown borage to be exceptionally attractive to beneficial bugs with an average of over 100 beneficials found in just 1-square-yard of borage. In addition, common green lacewings have a very strong preference to lay their eggs on borage. Look for it on garden center seed racks and mail order seed catalogs.
This 6- to 8-feet tall native perennial has a unique feature that makes it a star in beneficial borders. The leaves wrap all the way around the stems, forming a deep cup that collects dew and rainwater. Beneficial insects and small birds can easily use the leaves as landing pads, and then drink from the cups. Cup plant is an outstanding ornamental with large attractive leaves and clusters of yellow flowers in mid to late summer that are highly attractive to many insects. To start seeds, sow in fall or store in damp sand in the refrigerator for 6 to 8 weeks before planting in spring.
This summer-blooming perennial has fuzzy violet flower spikes on 2- to 3-feet high plants with licorice-scented leaves. These nectar-rich flowers are very attractive to both butterflies and pest-eating beneficial insects.
This long-blooming perennial produces bright yellow 2-inch daisies that are highly attractive to five key beneficials: ladybugs, lacewings, flower flies, tachinid flies and mini-wasps. It was the only plant out of 170 species to score this well in a three-year study at botanical gardens in Colorado and Wyoming. Golden marguerite thrives in poor soils—so you don't even have to do one of the 10 Easy Soil Tests before planting—and grows 2- to 3-feet high and wide. Deadhead to promote rebloom and divide plants every two to three years.
Long-lasting fennel flowers are extremely attractive to all nectar-feeding beneficial insects and the feathery green or purple foliage looks wonderful in spring and early summer. Fennel is a host plant for the caterpillars of the Anise Swallowtail butterfly. The seeds and leaves are also eaten by humans and are excellent in salads or spaghetti sauce. These plants grow to be about 5-feet high.
Native mountain mint plants, and many other members of the mint family, are excellent choices for beneficial borders. They have broad clusters of small white flowers surrounded by unique, showy white bracts and it makes beautiful dried flowers. Mountain mints grow to about 2- to 3-feet tall.
Related: Why Mint Runs Wild
Willows are especially valuable because they produce pollen so early in the spring when many beneficials are just emerging. Pussy willows are easy to grow and fun to cut to use in a No-Rules Flower Arrangement. Most garden centers will carry them in spring or you can root cuttings from a neighbors' shrub in water.
All clump-forming grasses provide excellent summer shelter and overwintering sites for ground beetles, ladybugs and other beneficials. Studies in England found more than 1,500 predators per square yard in grass-covered "beetle banks" planted in arable fields.
Corn tassels produce large amounts of pollen that is a nutritious protein source for many beneficials. And while we usually don't think of corn as ornamental, it's actually very striking when planted in flower beds. Think of it as a very fast-growing, tall ornamental grass. If you want an extra bit of beauty, try Japonica corn which has green, white and pink variegated leaves.
Other options for border pest control include:
Basil, Bee Phacelia, Birds Eyes, Blue Lace Flower, California Poppy, Candytuft, Chervil, Coriander, Corn Poppy, Cosmos, Dill, Lobelia, Meadow Foam, Mexican Sunflower, Pincushion Flower, Signet Marigolds, Sunflowers, Sweet Marjoram, Tidy Tips.
Asters, angelicas, Basket of Gold, Bishop's Weed, blanketflowers, Blue Cardinal Flower, Bog Rosemary, Catmints, Carpet Bugleweeds, cinquefoils, Comfrey, coneflowers, Coral Vine, coreopsis, Crimson Thyme, crocus, Evening Primrose, Feverfew, Garlic Chives, Goldenrod, Jerusalem Artichoke, Lavender, Lavender Globe Lily, Lovage, lupines, milkweeds, Mountain Sandwort, peonies, Pincushion Flower, Poppy Mallow, Queen Anne's Lace, Rocky Mountain Penstemon, Sea Lavender, Sea Pink, stonecrops, Fernleaf Tansy, Teasel Thrift, Toothpick Ammi, Wild Bergamot, Wood Betony, yarrow, Patrinia.
Trees + Shrubs
Boxwood, Forsythia, Firethorn, Potentilla, Ceanothus, Four-winged Saltbrush, Euonymous, Texas Sage.
Blue Wildrye, Deer Grass, Orchard Grass, Tufted Hairgrass, Velvet Grass.