A walkway of irregularly shaped stepping stones led to a side door of the house I grew up in. Between and around those stones grew woolly thyme that bloomed and attracted bees all summer. When I stepped on it, crushing the leaves, it released a wonderful fragrance.

What I remember most (besides the bees, which always frightened me), is the resiliency of that thyme. No matter how many people trampled it, the fragrant plants never looked beaten or worn down.
           
I’ve always been interested in groundcovers for their different textures, colors, forms, and—let’s face it—their utility. There’s nothing like the dense, glossy leaves of European ginger to keep the weeds out. And, who can resist the delicate flowers of Epimedium nodding in the breeze or the way the wind ripples over its heart-shaped leaves? For years, professionals have been telling us to replace all or part of our lawns with moss or a variety of native plants and groundcovers.
           
Ground-covering perennials can help replace a lawn, fill in spaces in a pathway, hold the soil on a slope, absorb excess water under a faucet, or spill over the bricks in a patio. Some companies make planting “walkable” ground covers easy for even a novice gardener, offering plants whose tags tell you how much traffic a plant will bear, the amount of sun and/or shade tolerance it has, and how to grow it.
           
For lightly-trafficked areas, you might choose Roman Chamomile (Chamaemelum nobile) instead of grass to form a lawn. When walked on, the chamomile exudes a wonderful fragrance. It will also thrive in well-drained soil in spaces between patio stones. This is not a particularly tough plant, so make sure it gets planted away from main traffic areas.
           
Another group of plants for light traffic areas is the sedums. Individual plants are tough and indestructible. They need very little water and even less attention. They like good drainage and hot, sunny sites. Under these conditions they spread rapidly. If walked on more than a few times each week, they begin to look unkempt. Look for varieties of Sedum hispanicum, for Sedum acre or for Sedum spurium ‘John Creech’. Miniature stonecrop (Sedum requieni) is the exception. It can take the heaviest foot traffic.
           
For areas in which you walk once or twice a day, you might want to try ajuga (“bugleweed”). It does well in sun or shade and comes in an amazing array of colors and variegation. Apiga ‘chocolate chip’ is a small, tight groundcover with leaves that resemble chocolate chips in color.
           
Creeping Jenny or Lysimachia will also do well in areas with moderate traffic. It likes moist areas with partial shade, but will tolerate harsher growing conditions. It has leaves the size of a nickel and spreads by runners. Lysimachia nummularia ‘Aurea’ has gold foliage. Lysimachia japonica ‘Minutissima’ has super tight evergreen foliage. Unfortunately, this one is a slow grower. Other creeping groundcovers that do well in areas of moderate traffic include Mazus reptans “Alba” or Purple, a bright green, low-growing mat that spreads quickly, as well as many of the speedwells (Veronica species) and Labrador violets.
           
For areas of heavy traffic, thyme is a great survivor. It tolerates being walked on several times a day and has a wide range of leaf colors, including golden, variegated, and different shades of green. Flower color varies from white to pale pink to deep purple. Look for white or red creeping thyme, woolly thyme, miniature thyme or Thymus x citriodosus ‘Doone Valley’, a type with green and gold variegated leaves that develop a hint of red in winter.

Irish moss, Sagina subulata ‘Irish Moss’, which forms a dense carpet, also bears heavy traffic.
           
To get started with stepable groundcovers, follow these suggestions:

• Pick the right plant for the right spot. Make choices based on how much sun/shade you have, how moist your soil is, and how much foot traffic you will have.
• Calculate the number of plants to buy by measuring the size of your planting area (or the spaces between your stones or pavers) and dividing it by the spacing recommended for the species you’ve chosen to plant.
• If you have tight spaces you can divide the plants to fit them.
• Plant at the same depth as the soil line in the pot.
• Water well after planting; continue to water on a regular schedule until plants are established.
• Once your plants have become established, keep them contained by mowing or edging.  
        

By Margaret Hagen, UNH Cooperative Extension Agricultural Educator

For more information call the UNH Cooperative Extension's Family, Home & Garden Center's Info-line (toll free) at 1-877-398-4769 or send us an email. Volunteers are available to answer your questions Monday through Friday 9:00am to 2:00 p.m.

4/7/06