Tackling those trouble spots with ground cover

By Melanie Mathieson
Gardening Guru

Do you have an area in your yard which, because of terrain, or other reasons, isn’t a prime gardening location or lacks a “finished look” because of the bare earth or weedy areas showing? Maybe you have steep slopes or banks that although can support grass, which is unsafe to mow and maintain in these areas, needs a plant cover that will prevent erosion and is easy to maintain. Or do you have areas under your large shade trees that seem to only grow good crops of moss and the odd weed? If you have answered yes to any of these gardening situations, you may want to consider perennial plants classified as ground covers, to deal with these problem areas.
The advantages of ground covers are that they cover bare ground and often grow where no other plant will survive. There are literally thousands of plants from around the world that are considered ground covers. A respectful amount of these plants will grow in the growing zone of the Rainy River District (Zone 4).
The suitability of a plant to use as a ground cover is determined by its growing habits, not necessarily by size or by height. Typically, ground covers sprawl, spread, run, or colonize by reseeding. Some ground covers will only grow in full sun, while others do very well in areas of full shade and/or poor soil quality. You can find many species that will grow in moist to very moist conditions as well as those that tolerate drought-like conditions. Ground covers come in a wide range of sizes, colors and textures, adding interest, beauty, and uniformity to the garden. Make your plant selections carefully, so that the plants are suited to your climate, HYPERLINK “http://www.thegardenhelper.com/hardiness.htm” \o “Plant hardiness zone maps” \t “_blank” plant hardiness, water availability, HYPERLINK “http://www.thegardenhelper.com/acidsoil.html” \o “How to test and adjust your soil acidity” \t “_blank” soil pH and light exposure.
Once established, ground cover plants usually require little or no maintenance, usually some bone meal sprinkled over it in the spring and fall is all they need. Some ground covers look neater with an occasional pruning or mowing. Normally, however, the only necessary pruning will be to remove damaged foliage or disproportionate, straggling branches, or just to keep the plant confined to its allotted area. Gardening Guru Tip: With ground covers like ajuga (bugleweed) and lambs ears I like to cut off the flower spikes a soon as they emerge in order to direct the energy back into the plant so it will spread faster.
Ground covers are planted in the same manner as other perennials or shrubs. Generally, they should be planted in the spring or early summer to allow them time to become established before winter. As in other areas of the garden, you will want to “stage” your ground covers so that the lower growing types are in the foreground, with the taller shrubby varieties as the backdrop. You can plant low growing annuals in the spaces between your permanent ground covers as a temporary “fill in” until the perennials become established. The attributes of groundcover species in general, make them very useful for several purposes, including weed and erosion control. But be warned many of the species of plants recommended as ground covers can be considered invasive in regular perennial gardens. That is the characteristic that make these plants perfect for filling in quite quickly in problem areas.
The first step in HYPERLINK “http://www.thegardenhelper.com/plantingsite.html” \o “Prepare your planting site” \t “_blank” preparing the new area is to rid the soil of all the HYPERLINK “http://www.thegardenhelper.com/weeds.html” \o “Control weeds in your garden” \t “_blank” weeds and debris. Till the soil first, and then mix in organic matter, such as HYPERLINK “http://www.thegardenhelper.com/compost.html” \o “Turn your garden waste into food for your plants” \t “_blank” compost, peat moss, or manure into the top eight inches of the soil. Usually, you will plant your ground covers about a foot apart, but if you need a quick cover up, you can plant them closer together. As the groundcovers fill in, you can dig up some of the established plants and plant them in the bare areas or in a new area.
Water your ground covers regularly for the first year to ensure their survival and to help them become established. Apply a thick layer of mulch to control weeds, conserve moisture, and moderate the soil temperature. It may require a year or more for your ground cover to become established and begin to spread, depending on the type of plant and the conditions. Once they become established, ground covers will usually maintain themselves with a minimum of watering and care.
The true success to groundcovers is to select the plant that is appropriate for your need. Once you determine the growing conditions of your problem area, you can narrow the list down to just the suitable groundcovers. From here I suggest that you take the time to research your favourites in the available literature. This will help you to determine the best plant for your conditions and cut down on disappointment if the wrong plant is chosen. Below is an example some great groundcovers that grow well in the Rainy River District. Note there are many more plants that will grow in Zone 4 and are suitable as groundcovers. The internet or a good gardening reference book can assist with the research.
Ajuga (Bugleweed): Full to partial shade; evergreen
Bergenia: Full sun to partial shade; evergreen; blooms very early spring; grows just about anywhere.
Day Lilies: Although not usually listed as a groundcover species I have found through experience that day lily species can make suitable groundcover plants in full sun locations. Once they become established and start multiplying they form a dense mat of roots, making them great for areas needing slope stabilization. Blooms from mid to late summer; endless varieties available.
Ferns: Full to partial shade; moist and fertile soils; great for woodland gardens.
Goutweed (Snow on the Mountain): Full to partial shade; drought tolerant; very invasive; can be pruned back when it gets spindly in late summer.
Heuchera (alum root, coral bells): sun to deep shade; available in many varieties of leaf colour and leaf shape; like rich soil; some varieties considered ever-blooming.
Hosta: Many varieties available; Hostas look great in mass plantings; full to partial shade.
Iris: Although not usually listed as a groundcover species I have found through experience that bearded iris and Siberian iris species can make suitable groundcover plants in full sun locations. Once the irises become established and start multiplying they form a dense mat of corms and roots. This makes them great for areas needing slope stabilization. Blooms from spring to mid-summer.
Lady’s Mantle: full sun to partial shade; blooms from spring to mid-summer; well drained soils.
Lamium: Considered invasive in the perennial garden which makes it a great plant for problem areas; full sun to deep shape; different varieties ranging from silvery green to yellow green; likes most soils types; blooms in late spring until early summer.
Oriental Poppies: also not considered a typical ground cover but they are pest, drought and heat tolerant; multiply fairly quickly; bloom for 2-4weeks; deep tap roots make them ideal for slope stabilization. Note: The annual varieties of poppies can also work as they are prolific at reseeding which allows them come back year after year. This is why most people mistake them as perennials.
Phlox (creeping variety) – easily established; blooms in spring; many colours available; full sun; well drained soils.
Pulmonaria (lungwort): Full to partial shade; blooms in spring; a few varieties available for Zone 4 with a variety of colours, leaf shapes and patterns available; likes moist soils; good in woodland garden settings.
Saxifraga: Full sun to deep shade; moist soils; good in woodland garden settings; hard to find in local nurseries but a few varieties can be located in the region; fills in between rocks really well.
Sea Thrift: Full sun; moist and fertile soils; large volume of pink or white flowers lasting at least a month.
Sedum: many varieties available; full sun to shade depending on variety; many heights also available.
Snow in Summer: Full sun; drought tolerant; dusty green leaves with white blossoms; really pretty once established.
Wild Ginger: Full to partial shade; well drained soils; subtle and unique flowers; great for woodland gardens; I have this in my Thunder Bay garden and love its foliage.
Viola: this refers to the perennial violet varieties now available for our zone; full sun, moist soils; flower and leaf colours vary; I have in my Thunder Bay garden and look great growing at the base of tree trunks and in rock gardens. NOTE: The annual varieties of pansies and violets (Johnny jump-ups) can also work as they are prolific at reseeding which allows them come back year after year. This is why most people mistake them as perennials.