72 Basic Perennial Garden PlantinG & Maintenance
Aphids, spider mites, and more
Aphids, spider mites, and spittlebugs are sucking insects that sometimes affect
perennials, although these pests generally don’t do much damage to the plants.
Heliopsis, for one, is often loaded with aphids without any sign of harm, at least
not until early September, when most flowering is finished and the plants are
beginning to decline a bit anyway. If aphid damage becomes evident after
flowering, the entire plant can be cut to the ground. Aphids, spider mites, and
spittlebugs can be washed off with a strong spray of water.
Thrips can damage flower buds or distort petals and stunt growth on perenni-
als such as daylilies (Hemerocallis). Affected plant parts should be pruned off and
destroyed. This might mean shearing down the troubled daylily, but it will
develop new growth in a number of weeks, depending on the moisture it receives.Lily leaf beetles
Lily leaf beetles, first spotted in the United States in the 1990s, have become a
growing problem and are now found in the New England states, New York, and
Washington state. These bright red beetles feed voraciously both as adults and as
larvae on lilies (Lilium spp.) and fritillaries (Fritillaria spp.), occasionally dining
on Solomon’s seal, lily-of-the-valley, and hostas. Regular handpicking of adults,
larvae, and eggs (found on the undersides of leaves) is the recommended form of
control. It isn’t a job for the squeamish, as the young cover themselves in their
own excrement as a deterrent to predators. As adults, their defense mechanism
is to drop to the ground when disturbed, sometimes emitting a little squeak.
Researchers are working on finding a safe and effective biological control for this
troublesome pest.Other pests
Rabbits, raccoons, squirrels, chipmunks, and deer all add to the already challeng-
ing world of perennial gardening. Most of us have problems with at least one if
not several of these beasts.
My best defense against most such garden intruders are my cats, which live
exclusively in the gardens and woods of our property. They are of great benefit
against the small rodent-type pests. I have had little problem even with rabbits,
thanks to the cats, which is incredible considering our home’s country setting. IChicken-wire fencing around an
island bed of perennials can be
used to keep rabbits at bay.