Roll Out The Carpet
Any plant that stops sunlight getting to the soil will slow weed growth, says Adrienne Wild
Not only do ground-hugging plants do the best job of keeping weeds at bay – especially in areas where lawn isn’t an option – but they’ll help stabilise the soil on a slope. There are plenty of suitable plants to choose from, but before you rush out to buy those labelled ‘ground cover’ at the garden centre, you need to assess your site and soil. Plants that will thrive in the dry shade beneath trees won’t take well to a damp patch or a hot spot – you need the right plant for the right place. Lady’s mantle or alchemilla is a tough plant and ‘made’ for problem areas. It is droughtresistant and tolerates all soil types, including chalk, and can be grown in full sun or partial shade. Another positive is that this attractive herbaceous plant is very promiscuous and self-seeds everywhere, spreading rapidly throughout the garden to produce ground-hugging clumps of light-green foliage and frothy sprays of tiny green/yellow summer flowers that don’t give weeds a look-in!
St John’s wort or Hypericum calycinum spreads via underground stems (rhizomes), sending up new plants that allow an untamed specimen the chance to run amok through borders. It is, however, still worth considering if you want to cover a slope that’s tricky to mow or any other area that needs to be protected from erosion. The variety ‘Hidcote’ is the most popular, producing a semi-evergreen mound, which from June to September almost disappears under a cloak of large saucershaped, golden-yellow flowers.
For long-lasting summer colour you can’t beat, go for hardy geraniums. The variety ‘Johnson’s Blue’ is one of the best weed suppressors as it produces dense clumps with finely divided leaves and violet-blue flowers up to 5cm across from midsummer until the frosts. It will do a good job in well-draining soil in sun or partial shade, and if you cut it hard back immediately after flowering, it will regrow and produce some late blooms. In the autumn, the foliage also takes on brilliant orange and red tones, extending the plants seasonal interest even further.
Another plant that will make a statement is bergenia or elephant’s ears, which is valued for its bold, architectural foliage, which often turns shades of maroon, crimson and bronze in winter. The enormous leaves play second fiddle, though, when clusters of tiny pale pink, white, ruby red or dark purple bell-shaped blooms emerge on spikes up to 30cm tall in April and May. Bergenias appreciate good soil, growing happily in shade or sun as long as the soil is not too dry. Plant them 30-45cm apart and plants will soon cover every spare inch of ground, keeping weeds at bay.
Also known as coral bells, heucheras begin blooming in early June and don’t stop until the end of August. It’s the foliage, however, that makes heuchera a winner. Purple, black, red, orange, brown, silver, chartreuse... you name it, you can most likely find a heuchera in that colour. Dark-leaved varieties look especially good with silver-leaved plants like artemisia, blue fescue grasses and ground-hugging Lysimachia nummularia ‘Aurea’, which has, as the name implies, golden leaves that creep across the soil.
Bugle or Ajuga reptans is an easy-going ground cover favourite that’s fairly quick to establish into a dense evergreen mat, spreading aggressively by runners and creeping into every nook and cranny. It will grow in sun or partial shade and is not fussy about soil so long as the drainage is good. The plants flower in early summer, producing rabbitproof blooms on short spikes that are often blue to purple and rising about 25cm or so above foliage. The leaves can be attractively blotched coppery, which is sometimes described in plant catalogues as ‘chocolate brown’, or purplish as well as green.
The dead-nettles Lamium ‘White Nancy’ and ‘Beacon Silver’ have the shiniest silvery leaves, so are especially useful for lightening up shady spots. Mulching around these sprawling plants in spring will encourage them to fix loose stems into the soil with tiny roots – with the result that they create a tight-knit, ground-hugging mat that will also help trap moisture in the soil.