Beneficial Borders: An Organic Solution to Garden Pests
By Sonya Welter
“Feed and the pests will come,” seems to be every gardener’s motto.
We may never see a pest but as soon as we plant the first tomato or pepper the swarms seem to appear.
But a unique concept of feeding and nurturing nature’s insect task force will bring even the novice gardener relief.
The concept is simple provide shelter, water, and food for beneficial insects and let nature take its course. So try a beneficial insect border around your garden and see how nature works without chemicals. Who knows you may decide to do a whole beneficial insect garden to reward nature’s insect task force.
SWEET ALYSSUM (Lobularia maritima)
This annual is low growing and produces white flowers that can form a border in a flowerbed or can act as a fast-growing ground cover that vegetables can be planted into. Many studies have shown that sweet alyssum is highly appealing to aphid eating hover flies.
CUP PLANT (Silbium perfoliatum)
This perennial grows to 6-8 feet and possesses a unique feature that makes it a star in any border garden. This plant’s leaves wrap around the stem to form a deep “cup.” These cups collect dew and rainwater while creating a “landing pad” for beneficial insects and small birds that can use them while drinking. The large leaves and clusters of yellow flowers that appear from mid-to-late summer also make this plant a showstopper but is only hardy in USDA Plant Hardiness Zone 3 or 4.
Corn
While this plant in a border bed may seem odd and out of place one only has to look at the beauty of this plant. The corn tassels shooting up in the air produce large amounts of pollen while adding textural interest to your border. This pollen also attracts ladybugs, pirate bugs and many gardening friends that will help themselves to numerous garden pests.
Ornamental Grasses
These clump-forming plants planted in mass provide exceptional shelter from the summer heat and over wintering sites for ground beetles, ladybugs, and other beneficial insects. Several studies done in England found that as many as 1,500 predators existed per square yard covered in ornamental grasses. This plant creates cheap “hotels” for the insects you want to keep and visual interest for any border garden.
PUSSY WILLOWS (Salix)
All willows are early pollen producers, which is very valuable to beneficial insects just emerging in the spring. This plant is a knockout in the spring, which can be cut and forced for indoor enjoyment. Willows are extremely easy to grow and simply take a cutting placed in the ground to start.
BACHELOR’S BUTTONS OR CORNFLOWER (Centaurea cyanus)
These annual plants add a beautiful blue color component to any border garden. They also possess a unique habit that is called extrafloral nectaries. This means that even when the plant is not flowering the leaves are producing nectar. German research has shown that Bachelor’s buttons nectar is 75 percent sugar, which hover flies, ladybugs, lacewings, and beneficial wasps love. To start in your border garden sow seeds in the fall or early spring and do not worry about replanting next year they are prolific reseeders.
BORAGE (Borago officinalis)
This annual herb produces bright blue flower clusters that are edible and have a refreshing cucumber taste. But humans are not the only ones that like this herb. A study in Switzerland discovered that borage is an excellent attractant to good bugs. It has been found that more than 100 beneficial insects where found in 1 square yard of borage. Also common green lacewings favor borage as a place to lay their eggs.
GOLDEN MARGUERITE (Anthemis tinctoria)
This perennial produces long lasting bright yellow daisy like flowers that can span 2-inches. It is highly attractive to ladybugs, hover flies, tachinid flies, lacewings, and miniwasps. During a 3year study done at botanical gardens in Colorado and Wyoming golden marguerite beat 170 species as far as the best beneficial insect attractant. This plant is hardy in Zones 3 to 7 and thrives in poor soil. It grows 2 to 3 feet high and wide. This plant will need to be deadheaded to encourage reblooming and will need to be divided every 2 to 3 years.
MOUNTAIN MINTS (Pycnanthemum Virginianum and P. muticum)
Members of the mint family are excellent for beneficial borders especially the native mountain mints. The short-toothed mountain mint (P.muticum) produces broad clusters of small white flowers that are surrounded by unusual, showy white bracts. The flowers of this plant can also be dried for indoor decorations. Mountain mints grow 2 to 3 feet in height and are hardy in Zones 4 to 7.
FENNEL (Foeniculum vulgare)
Fennel graces many human plates with its delicious flavor but beneficial insects also enjoy it. The flowers of the fennel plant are long-lasting and provide a source of nectar for beneficial insects while the foliage creates spring and summer visual interest. Anise swallowtail butterflies lay their eggs on fennel, which creates a host plant for its caterpillars. This perennial plant grows 5 feet in height and can be planted in Zones 5-9.
May 22nd, 2010 at 7:06 pm
I believe the cup plant’s genus is Silphium
May 27th, 2010 at 12:44 pm
Cup Plant’s genus name is indeed Silphium.
Also, Reggie, I didn’t write this. I think my byline must’ve accidentally gotten tacked onto somebody’s else’s article.