Replacements for Ivy
Shade Loving Groundcovers to Replace Invasive English Ivy
by Betsy Washington
English Ivy is invasive in most parts of the country and especially so along the east coast where it is often a noxious weed. Ivy spreads aggressively by runners and will quickly smother other plants. It will also readily climb any tree in sight, and once it has climbed into sunlight, it produces clusters of fleshy black seeds that are dispersed far and wide by birds. It has caused millions of dollars in damage to our parks and natural areas by decreasing biodiversity and smothering shrubs and trees.
If you are considering removing ivy from your own garden as part of Invasive Plant Removal effort, I recommend starting with a small, manageable area. Begin by cutting any vines growing up trees, and removing vines near the base – this will prevent the production of fruit and protect your trees. Pulling ivy is hard work, as the roots spread far and wide. You can also smother vines with heavy sheets of plastic or newspaper. As a last resort, you can use a broadleaf herbicide, but remember that all herbicides are toxic to other plants and to wildlife (including you!) so never spray near the lake and always wear protective clothing. It is safer and more effective to paint the ends of the cut vine with glyphosate (Roundup) or to treat the ivy when new leaves are emerging in spring, since the waxy coating on mature leaves resists treatment. You may need to repeat the removal process several times before you get rid of all of the ivy. Be sure to remove and destroy all pieces of cut vine, as it will root and spread if left lying on the ground. These techniques work equally well with other invasive vines such as Porcelainberry vine, and Japanese Honeysuckle.
Once you have cleared an area, I recommend following nature’s example by planting several tough, spreading groundcovers to add diversity. First spread a layer of composted leaf mulch over the area; it is often available free at many local municipalities. This will help prevent erosion and allow dry soil hold water and nutrients and to give new plants a chance. In large areas where a vigorous groundcover is needed, try a couple of our native ferns. The Hay-scented fern, Dennsteadtia punctilobula has a delicate appearance that belies its rugged nature. It spreads quickly by underground runners to form large, dense colonies, that crowd out weeds, even in dry shade. It is best suited for areas where it has room to spread and won’t crowd out other plants. New York fern, Thelypteris nove-boracensis, is another good choice. It also spreads into large mats via creeping runners making an excellent groundcover even in dry shade, and it is less aggressive than the hay-scented fern and better suited to smaller areas. Both these ferns are deciduous, so if you want an evergreen groundcover, try our native Christmas fern, Polystichum acrostichoides. It is a clump former so does not spread into colonies, but is well adapted to covering steep, wooded slopes where other plants would fail. It is easy to dig up and divide every few years to increase your plantings. Try placing several clumps of our Wild Ginger, Asarum canadense, with its large, rounded leaves, in front of the ferns. The bold foliage contrasts wonderfully with the lacy fern fronds and the wild ginger will spread into large ground hugging colonies. If you are hankering for flowers, try adding one of our native phloxes to the mix. Wild Blue Phlox, Phlox divaricata, has fragrant blue flowers for weeks in April and May and spreads easily to from large clumps. It is easy to divide and spread around to create large carpets of fragrant blue flowers in spring and it also performs well in dry shade. The White Wood Aster, Eurybia divaricata, is another excellent groundcover, that spreads freely into large colonies and is covered in small white flowers in late summer through fall, brightening a shady garden. You can check out many of these plants in the RPA Demonstration garden.
If you would like to replace your lawn in a small, shaded area, you might consider planting the native Pennsylvania Sedge, Carex pensylvanica. It is evergreen, with fine grass like leaves to 9" tall, and spreads into a tough and lovely sedge lawn that never needs mowing. It is adapted to moist or dry shade. Edge your sedge lawn with the lovely Allegheny Spurge, Pachysandra procumbens, with handsome lobed and mottled leaves and pink tinged white feathery flowers in spring. It is much more attractive than the ubiquitous Japanese Pachysandra, but does not spread as quickly. The bold foliage would make a handsome frame and contrast to the fine sedge.
If your area is damp and shady, the lovely Ostrich fern, Matteuccia struthiopteris, would make a lush groundcover with its large, graceful fronds. Try mixing it with Golden Ragwort with gold flowers in spring and heart-shaped leaves. Both will spread into large ground-covering drifts that will crowd out weeds. The lovely blue flowers of Virginia Bluebells, Mertensia virginica, would add the perfect finishing touch.
Other non-native perennials come to mind and are tough enough for the job, but are well behaved in the garden. Lenten roses or hybrid Hellebores bloom for months in late winter and once they are established, they will seed around forming colonies. Hostas are also tough and easy to divide and spread around, creating a lush woodland groundcover. They come in a dazzling array of sizes, colors. Epimediums also make splendid groundcovers. There are many selections to choose from with evergreen or deciduous foliage and dainty, spurred flowers. All of these would consort well with the native groundcovers listed above.
With a little work, perhaps your former eyesore will become a destination, instead of a maintenance nightmare. Try adding a mulched or stepping stone path that wanders through your new plantings and you may be pleasantly surprised at how great the area looks in a few years time. You might even find yourself thinking of adding a birdbath or bench so that you can linger and enjoy your new garden!