Selecting GroundCover plants

Groundcover plants make a close and dense layer of vegetation over the soil surface, preventing weeds from becoming estab­lished. Initially, weed-free ground is essen­tial, as the plants will take a couple of seasons to cover the ground fully and will not suppress established perennial weeds, such as couch.

Groundcover plants include shrubby species, such as Rubus tricolor and Hyperi­cum calycinum, which remain green all winter, and herbaceous plants, such as hostas and geraniums. The annual maintenance is slightly different for the two groups.

Herbaceous plants should have the dead tops removed after they have died down. This should be carried out in late autumn or over the winter. Any woody weeds, such as brambles, should be dug out at the same time; any regrowth should be painted with Tumbleweed gel in early summer. Any bare patches, eg where plants have died, should be replanted at the same time, using surplus plants from another area. Despite leaving the ground surface bare and uncovered over winter and spring, the flush of growth in the spring is usually sufficient to kill any weeds which germinate over winter.

Woody groundcover plants will benefit from a periodic trim. With most, this should be carried out in early spring and the plants will quickly re-cover the ground. It does not need to be an annual operation. Plants like heathers will benefit from the old flower heads being removed after flowering, ie in the autumn for the summer flowering ones, and in late spring for the winter flowering heathers. Some woody groundcover plants also tend to spread outside the confines of the allotted space and will need regular cutting. This is particularly so with vigorous plants like Rubus tricolor which makes long growths to 2m (6′/2ft) in a season and will tip layer the ends of the shoots.

Some groundcover plants, eg Hypericum calycinum and hemerocallis, will spread by underground root suckers. The perimeter of the area may need to be dug once a year to prevent spread.

Groundcover will benefit from the occa­sional feed, but apart from herbaceous ones, should not need mulching once established, as the natural leaf litter is usually left in situ. Most forms of groundcover will last ten to fifteen years before needing to be replanted or divided.