Nursery Companion Plants for Beneficials
Plants that provide food and shelter for pest-eating insects
are valuable in any kind of garden. Beneficials are invited to your home and
given lots of food and shelter. Even when the pests are not readily available,
supplemental food can be obtained from these other plants. They also can offer
nourishment to the nonpredatory stages of these insects.
Most plants can shelter beneficials, but some practically
have neon signs welcoming the beneficials to your garden. The best flowers
are small and abundant, like yarrow, coneflowers, thyme, and catnip. These
flowers have easily-accessible sources of nectar and pollen that many beneficials
need to supplement their diet when pests are scarce.
To attract and keep the widest variety of beneficials, make sure something suitable is in bloom throughout the growing season for a constant supply of food. Mix the attractant plants amongst the plants you are trying to protect, so that the predators and parasites will always be close to your crops and ready to attack when pests appear. If you find egg cases on pest bodies, you've got a sign that the system is working.
Other things you can do to attract and protect the beneficial
insects include providing "bug baths" - shallow dishes of water
filled with small rocks for perches; including groundcovers, mulches, and
stepping-stone paths in your garden plans to give hiding places for rove and
ground beetles; planting a variety of plant species with different heights
and shapes to provide the best shelters for a wide variety of predators; installing
a fence or hedge as a windbreak to reduce dust which can cause beneficials
to dehydrate quickly.
Best Beneficial Plants
Daisy Family (Compositae) These blooms are excellent
sources of both pollen and nectar and attract a wide variety of beneficial
insects, inclduing parasitic wasps, hover flies, green lacewings, assissin
bugs, and ladybugs. Annuals included in this family are cosmos, calliopsis,
marigolds, sunflowers, China asters, and dahlias. Perennials include coreopsis,
tansy, golden marguerite, perennial sunflowers, goldenrods, coneflowers, asters,
Mint Family (Labiatae) The aromatic foliage and clusters of small flowers can attract bees, hover flies, and other beneficials. Annuals would include basil and sweet marjoram. Perennials include thyme, mint, sage, lavender, hyssop, wild marjoram, catmints, Russian sage, and monarda.
Carrot Family (Umbelliferae) These plants have small flowers grouped into large unbrella-shaped clusters. They attract ladybugs, hover flies, parasitic wasps, spiders, lacewings, and other beneficial insects. Some of the favorite annuals include dill, caraway, and fennel. Queen-Anne's lace and the perennial angelicas are also good attractants.
Other attractive flowers for beneficials would include asclepias
and alliums. You might also try some of the green manures like buckwheat,
sweet clover, and white clover. There are also some weeds
that are good for beneficials. While you might not want to plant these, you
might leave a couple undisturbed in an unused corner of the garden. These
include, lamb's-quarters, dandelion, goldenrod, pigweed, knotweed, and wild