Ground Covers To The Rescue

Barb Mrgich
Adams County Master Gardener

Good ground covers serve several uses for a gardener. Like mulch, ground covers shade the soil. This cools the plant roots in hot weather and also reduces watering needs. The ground covers reduce the amount of sunlight hitting the soil, thus greatly reducing germination of weed seeds. They accomplish all this while looking very attractive and adding to the beauty of your garden.

Unlike mulch, many ground covers flower, and they are mostly permanent. Instead of decom-posing into the soil as mulch does, ground covers expand to cover more territory each year. Ground covers are also a good answer to controlling erosion on steep slopes.

Most ground covers are what we might refer to as aggressive plants. This sounds bad, but in their case, it is a good trait. The more real estate they cover, the less mulch you have to buy each year.

Like all plants, before planting, you need to consider the light, water, and soil requirements of the ground cover. Here’s an example, Pachysandra is a well known ground cover for the shade. Lamium maculatum, commonly called Spotted Dead Nettle, also prefers shade. It has a pretty, variegated leaf which really lights things up, and, depending on the variety you choose, it gets a lovely flower in May that could be white or pink. It requires moist shade with good drainage, where the pachysandra will perform better in drier shade.

If you have a constantly moist shady area, try some native ginger. It makes a lovely ground cover and is host to the pipevine swallowtail butterfly, but it will die out in dry soil.

A versatile native ground cover which prefers damp shade, but will also do very well in the hot sun, is Golden Ragwort (Senecio aureus). Golden Ragwort, a Pennsylvania native, has a fairly large, dark green leaf, and it will spread quickly. In early spring it sends up bright yellow flowers that are very eye-catching for a full month.


Spotted Dead Nettle creates a bright spot in a shady garden

Ground covers can be very useful when you are starting a new bed. If you are putting in young shrubs or perennials, the young shrubs will usually start out small and they may take several years before they become large enough to fill in the bed. In the meantime, you have a lot of bare ground which is just beckoning weeds. The right ground cover will fill in quickly to cover the soil as the shrubs grow. Then it will be slowly pushed aside as they mature.

Some ground covers should not be used because they are invasive. Crown Vetch (Securigera varia) is an example of a ground cover that was used extensively during the 1960's and 70's to hold soil in place on the newly formed banks of major highways. That was before it was deter-mined that it is capable of escaping into the wild to crowd out native plants needed for survival by our native wildlife. You may be surprised to learn that English Ivy is also very invasive and should never be planted! You may think you can keep these invasive plants under control in your yard, but birds and animals carry the seeds to our natural areas where they choke out valuable natives, and you have no control over that!

Creeping Jenny, Lysimachia nummularia, looks lovely spilling its bright yellow leaves from containers, but don’t let it touch the ground. It will quickly take root and is very capable of escaping into the wild where it will smother small plants in its path. The plant is illegal in Massachusetts. As an alternative, there are a number of very pretty sedums which do the ground cover job nicely and are never invasive. Angelina sedum, which is bright yellow, is a great alternative that will take full sun, or a little bit of shade.

Some herbs make lovely ground covers. A favorite of mine is Berggarten sage. It has a lovely blue-green leaf that is a culinary treat. It spreads very slowly while doing a great job of shading out weeds. Flowering, creeping thyme also looks beautiful as a ground cover. It blooms for several weeks in June and July.


Flowering Thyme surrounds stepping stones on a garden path

Ground covers do a better job than mulch at holding soil in place to stop erosion. They are also very good at solving a dangerous mowing situation on a steep slope. Deutzia ‘Nikko` is one great plant for this job. ‘Nikko’ is a variety of deutzia that grows about two feet tall, and has dainty white flowers in spring. It expands when its graceful branches touch the ground and take root.

Another shrub used for this same purpose is Cotoneaster. There are at least two varieties that will stay low to the ground and cover a good bit of territory. Cranberry cotoneaster (C. apiculatus) grows only two to three feet tall but will spread as wide as six feet. It has pink blossoms in summer followed by red berries in fall. Its cousin, Cotoneaster bearberry (C dammeri) will reach about the same size, but will have white flowers in the spring followed by red fruit in late summer and bronzy purple foliage in fall.

There are so many other ground cover choices, far too many to be included in this article. Before choosing a ground cover, do a little research of your own, and make sure you are choosing the right plant for the right place.

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