People who like to pull weeds are a rarity. Pulling out weeds can be a happy enterprise for one who’s been ill, indoors or otherwise deprived of that pleasure, but usually most people dislike that chore. Weed prevention is the best bet overall.
One way to prevent weeds is to use an effective ground cover, preventing weed seeds from germinating. Sunlight on weed seed resting on soil plus water spurs germination, so the object of using a ground cover is to block out sunlight. That’s fairly easy in the vegetable garden, interplanting vines such as sweet potatoes, winter squash or melons with upright vegetable crops, but using cover crops in ornamental beds is more difficult because there are many choices.
There are ornamental sweet potato vines available, those looking almost black and others a vivid green. Some herbs could be used for ground cover. Oregano and sweet marjoram, species hardy to at least USDA zone 6, are dependable perennial vining plants, with vines growing to about 18 inches long. Mint and other balms are perennial ground covers, but they’re difficult to stop where you want them to stop. There’s at least one Achillea that spreads to cover ground, but even though it’s very drought tolerant, its effectiveness as a ground cover is limited because of its wispy leaves.
Sweet woodruff is an interesting herb for shady locations. Leaves and flowers of this ground-hugging herb are lightly scented, and are used by some to flavor May wine.
Anju Lucas, of the perennials department at Edwards Greenhouse, suggested some ground covers for full sun exposure: Zauschneria garrettii (Orange Carpet), Crystal River veronica and Nepeta Little Trudy catmint all hardy here, drought tolerant, attractive to hummingbirds and butterflies and not attractive to deer. The Zauschneria, also tolerant of part shade, features orange flowers mid-summer to fall and is evergreen in some locations. Crystal River veronica (speedwell) sports bright, intense blue blossoms from late spring to summer. Nepeta Little Trudy catmint blooms dark lavender or light purple, set against silvery green foliage.
Ground covers for shade sites that Lucas suggests are Monardella macrantha (Scarlet Monardella), Campanula Blue Waterfall (Serbian bellflower), Lamium aureum, Jack Frost brunnera and Clematis fargesioides. The Monardella will also tolerate full sun. Its blossoms are vertical shafts, appearing in mid to late spring. It is hardy to zone 7, so I’d place it in a fairly protected area.
The Campanula is hardy to zone 4 and can withstand full sun exposure. It blooms blue star-like flowers throughout the summer. This ground cover also has a cascading habit, so would be especially attractive on a hill. Chartreuse arrowhead-shaped leaves of the Lamium aureum brighten dark shady places, and this ground cover blooms on and off from spring into fall. The Jack Frost brunnera also brightens dark corners with leaves frosted white, and in early spring sends up tiny sky blue flowers on stems. I have this in my shade garden, but it has not stretched out to act as a ground cover.
Clematis, usually planted to climb, can be used as a ground cover, but some varieties don’t produce leaves sufficiently thick to block sun from soil. Sapphire Indigo Clematis (blooms from June to autumn) and C. Praecox jouiniana are said by some experts to be the best varieties for ground cover, although Lucas recommends C. fargesioides (Summer snow). She likes it partly because it has a light fragrance.
Other vines that can be used as ground cover include climbing hydrangea (grows very well in this area), wild ginger, or even Virginia Creeper, whether you want it or not.
Send garden questions to email@example.com or Gardening, The Statesman, P.O. Box 40, Boise, ID 83707.