9 Flowers To Grow From Seed That Attract Beneficial Insects To The Garden

Several annual and perennial flowers, easily grown from seed, attract what many gardeners call beneficial insects: bugs that act as predators to repel other insect pests that attack our crops and flowers. These flowers will bring beneficial insects to your garden using nectar to lure in the helpful insect predators, such as ladybugs, hoverflies, and lacewings, all of which eat the larvae of aphids (plant-sucking insects that can do real damage in the summer garden). Plants that attract these predator insects include a glorious assortment of colorful, long-blooming flowers, including marigolds, nasturtiums, zinnias, cosmos, calendula, borage, sunflowers, sweet peas, cornflowers, and sweet alyssum.

Planting annuals from seed, either in the fall or in the spring, is an easy way to add more diverse plant life to your flower and vegetable garden. You can also plant some flowers from seed that will turn into clumping perennials, including yarrow, dianthus, echinacea, and coreopsis. Check seed packets for proper timing and planting instructions. I love planting annuals in my vegetable garden, either sowing seeds between rows or in containers. I also sow flower seeds among perennials in my cottage-style garden to increase variety. Many annuals produce seeds that can be gathered in late summer to plant in spring. Below are some of my favorite varieties that will help you attract beneficial bugs.

Many gardeners plant marigolds near their tomato plants to help them thrive. I learned this trick from my father, who learned it from his father (an Italian immigrant and avid gardener). Marigolds (Tagetes spp.) contain compounds with pungent odors that repel pests like aphids and whiteflies. They also attract hoverflies, ladybugs, and parasitic wasps: tiny, non-aggressive wasps that lay eggs in the bodies of other pests, including leafhoppers and destructive beetles, eventually killing them. Marigold seeds can be gathered after the flowers go to seed. Plant them in spring, in seedling trays indoors, or outside after the last frost.

Sweet alyssum (Lobularia maritima) is a sturdy plant that produces fragrant, delicate-looking flowers in a range of colors from white to purple. It can be grown easily from seed and will often reseed itself in the garden but is not considered invasive unless you live in California. It's great for the vegetable garden because the plants form dense mats that help deter weeds from growing. Sweet alyssum flowers attract hoverflies, which are natural predators of aphids, a garden pest that attacks nightshade vegetables like tomatoes, peppers, potatoes, and eggplant.

Cornflowers (Centaurea cyanus) bloom in shades of blue, pink, and purple from late spring through summer. These nectar-rich flowers attract ladybugs, lacewings, and flower flies. Flower flies (syrphids) prey on aphids and other insects that suck on green plants. Cornflowers (also called bachelor buttons) are best planted from seed in the fall. They often reseed themselves, sending up new plants that are easy to pull up and move around as desired. Their ability to attract beneficial insects makes them a good addition to the vegetable garden. Still, don't plant these in Georgia or West Virginia, where they're considered invasive.

Sunflowers (Helianthus annuus) come in a range of sizes and colors, and the nutritious seeds provide a feast for birds and other wildlife. The large flowers attract many pollinators, as well as beneficial insects, including lacewings and ladybugs, making them useful for controlling vegetable garden pests. Be careful when sowing the seeds because they tend to attract birds and squirrels. Starting them in seedling trays and transplanting them into the garden can help prevent the seeds from being eaten by hungry critters, at least until autumn.

Sweet peas (Lathyrus odoratus) are colorful, sprightly flowers with a pleasing, sweet fragrance. They love to scramble up a fence or trellis, seeking the sun. The relationship of sweet peas to beneficial insects is slightly different from other flowers suggested here. The perfumed nectar of sweet peas attracts aphids, which can damage the plants, but the aphids, being so numerous, then attract hoverflies and ladybugs, which eat the aphids. These insects then hang around to eat more aphids on other plants. In this way, sweet peas are a sort of literal "honeytrap" for aphids and their natural predators. 

Cosmos (Cosmos spp.) have tall stalks, delicate spiky leaves, and colorful daisy-like flowers. These sun-loving annuals are magnets for parasitic wasps, hoverflies, and lacewings. They can be grown in rows, fitting neatly between vegetable crops. It's best to plant seeds indoors in spring to give them a good start before transplanting. I've also grown them by directly sowing them in the garden after the last frost. They come in gorgeous pastel and bright colors, with single or double petals: my favorite varieties are 'Rose Bon Bon,' 'Apricot Lemonade,' and 'Sea Shells.' Remember, they can be invasive in West Virginia.

Pot marigolds (Calendula officinalis) are daisy-like, edible flowers in sunny shades of yellow, orange, and pale pink. A plant with medicinal properties, it also attracts beneficial insects like ladybugs, hoverflies, and lacewings to the vegetable garden. In addition, these flowers exude a sticky liquid that traps aphids and thrips, holding them until other insects can finish them off. They're easy to grow: I collect the chunky crescent-shaped seeds at the end of the season, saving them to plant the following year. I sow calendula seeds every few weeks, beginning in late spring, to keep the blooms coming all season.

Colorful nasturtiums (Tropaeolum majus) are easy to grow from seed in spring. The flowers are edible, making them a suitable addition to the vegetable garden. These long-blooming annuals also attract useful insects, including lacewings, hoverflies, and ladybugs, that deter pests like aphids. Like calendula, nasturtiums are a "trap flower" that lures harmful insects away from nearby food crops, including squash bugs and leafhoppers. Plant nasturtium seeds in spring in containers, where their cascading vines of useful flowers will light up the garden. There are many single-color varieties, as well as multi-colored mixes like 'Aloha,' 'Purple Emperor,' and 'Alaska.'

Yarrow (Achillea) is a hardy, clump-forming perennial that is easily divided for replanting. The flat flower heads (known as umbels) attract many beneficial insects, including hoverflies, ladybugs, damselflies, parasitic wasps, and beetles that feed on garden pests. Yarrow can be grown by sowing seeds in the garden in the fall or spring when all danger of frost has passed. This attractive, long-blooming flower is perfect for cottage gardens and comes in many colors. Some of my favorite cultivars are 'Moonshine' (yellow), 'Apricot Delight' (peach and pink), and 'Pomegranate' (deep cherry red).