By Kate Wall
Bare soil in gardens is prone to drying out, erosion, increased temperatures and increased weed germination. This is usually prevented by adding mulch to the garden to act as a blanket on the soil. An alternative to mulch is to use ground cover plants. These low growing plants will cover the bare soil and protect it in the same way that mulch will – but have the added benefit of being living.
Ground cover plants are usually selected for their ability to remain low growing and to spread to fill the space available. Many ground covers spread by trailing stems which take root as they touch the ground, effectively making them a collection of many individual plants. Others are sprawling plants with only one central root system.
Ground cover plants are particularly useful in areas where a full but not crowded looking garden is desired. The low growing plants add interest and fullness but do not crowd the vertical space in the garden.
An effective ground cover can greatly reduce maintenance in a garden. These plants act as living mulch which does not need to be regularly replenished. This living mulch, if it is dense enough will be a very effective way to keep weeds down.
Ground cover plants can be any plant which covers the bare soil between other plants in a garden. This can be low ground hugging plants like the native violet or a sprawling shrub like a prostrate grevillea. In the case of sprawling shrubs, the plants may be as tall as knee height, but their prostrate nature means that the plant is wider than it is tall and is therefore able to give significant protection to the soil below it.
Ground cover plants can be used in areas of full sun, through to full shade. In areas too shady for lawns to grow, ground covers such as native violets, dichondra and Liriopes make an excellent lawn alternative. Isabella® Liriope muscari 'LIRF' PBR is an excellant 'mow once per year' lawn alternative and will handle up to 90% shade.
Many ground covers will be very effective in part shade, carpeting the ground between larger plants with lush green leaves and even flowers. The acapypha “red hot cats tails” does just this with an abundance of furry red flowers. The star jasmines are typically climbers but can make exceptionally effective ground covers in sun or shade. Flat Mat™ Trachelospermum asiaticum ‘FT01’ PBR is a good choice as it does not get leggy as the common form can and therefore needs much less pruning to keep it as a neat ground cover. Flat Mat™ can be grown on steep slopes or embankments, in sun or shade, and will form a dense cover which protects the bank from erosion. It will also be dense enough to suppress weeds, which is useful in hard to access locations. Shooting Star™ Trachelospermum asiaticum ‘SJ01’ PBR is another jasmine ideally suited for use as a ground cover, with the added feature of variegated foliage. The perfumed flowers of the jasmines add to their appeal as both a climber and a ground cover.
When using a creeper or vine as a ground cover, it is important to be aware of its potential to climb when it reaches taller plants. If it does it has the ability to smother other plants and may not be such a good choice for a ground cover plant. The common syngoniums are notorious for doing this. The varieties with attractive coloured leaves are less aggressive and make better choices for a ground cover in a shady garden. Alternatively use a plant which does not have the ability to climb. A dense planting of a low growing plant such as Little Phil™ Philodendron species ‘PHIL01’ PBR can make for a lush green ground cover in shady gardens without climbing larger plants.
Low growing creeping plants are also a good choice for ground covers. There are many succulents which do this providing soil protecting with a wide range of small fleshy leaves in a variety of shapes and colours. The native pigface, Aussie Rambler™ Carpobrotus glaucescens ‘CAR10’ PBR is a dense low growing plant which not only forms a dense ground cover but with the added bonus of masses of huge pink flowers. Succulents make excellent ground covers in dry or coastal areas due to their low water needs. Their fleshy leaves help conserve moisture in the soil for use by other plants growing nearby.
Other drought tolerant and free flowering native ground covers include Purple Fusion™ Scaevola humilis ‘PFS100’ PBR with masses of purple fan shaped flowers and Yareena™ Myoporum parvifolium ‘PARV01’ PBR with an abundance of white flowers. Both are highly suited to many different garden styles, including cottage, native, rockery and formal gardens as well as mass planting for landscaping.
Prostrate forms of hardy shrubs can also provide good ground covers. O So Fine™ Gardenia augusta ‘KEN04’ PBR is a very dense low growing gardenia, providing a weed suppressing ground cover with masses of highly perfumed gardenia flowers. Purple Pixie™ Loropetalum chinense ‘PEACK’ PBR is a dwarf shrub with a weeping form that lends itself beautifully to mass planting as a ground cover. The rich red/purple foliage can be used to provide vibrant foliage colour in the garden year round, and is complimented by showy pink flowers in spring.
Dwarf and prostrate forms of many natives also provide excellent ground cover options. Gold Cluster™ Grevillea juniperina ‘H22’ PBR and Royal Rambler™ Grevillea ‘RR01’ PBR are two particularly low growing grevilleas which form dense ground covers quickly without needing pruning to keep them low. An abundance of flowers in yellow and red add extra interest. Cherry Cluster™ Grevillea rhyolitica x juniperina ‘ TWD01’ PBR is a slightly taller grevillea, growing to 50cm, which can also be used as a dense ground cover. It has masses of very showy red flowers from Autumn to spring and makes a very hardy low growing plant.
Another prostrate native plant which offers a very different look as a ground cover is Free Fall™ Casuarina glauca prostrate ‘CAS01’ PBR. It is ideally suited to steep slopes or cascading over retaining walls and provides excellent erosion protection with its fine cascading needle like foliage.
Choosing a ground cover plant which adds interest to your garden is a wonderful way of reducing maintenance and increasing the fullness and diversity of your garden, and with so many wonderful plants available there are good choices available to provide ground covers for any garden situation.