Ground cover plants seem to be nature’s gift to gardeners. They promise a colourful and interesting way to fill expanses of the garden while smothering weeds. A few decades ago they were all the rage. Before that it was heathers and conifers which was very much the same thing. Now it is prairie planting. Many ground cover plants deserve a place in the garden and they are useful but I need to be honest with you – they are rarely perfect. As a rule, those that cover the soil quickly also rapidly spread too far and look scruffy and those that grow slowly need a lot of weeding.
After all, if a plant is to fight off weeds and spread over your soil there is a good chance that it wont know where to stop! Ground elder is a wonderful ground cover plant. Of course I jest – or do I? Apart from the flower stems it is low growing so will not harm shrubs and it will grow in sun or shade. I do not have it in my garden and I do not intend to introduce it. But there are two variegated forms and I have a small patch of one. It is almost as invasive as the weedy form but is effective ground cover in the right spot. And because it is dormant in winter it can be planted with spring bulbs.
Having shocked you with the idea of planting ground elder – and I have total sympathy with anyone battling this pernicious weed because I have spent a good proportion of my gardening time trying to eradicate it – I need to mention a few basics and a few examples.
Ground cover is most useful for banks and other areas where weeding is not easy. With the exception of the most invasive plants, no ground cover plant will spread and eliminate existing weeds. So you need to remove all perennial weeds before you plant and you will need to weed the area as the plants spread and cover the soil. Once you have planted your ground cover you cannot use weedkillers to control weeds. You can’t plant ground cover to smother bindweed!
I will briefly mention ‘weed fabrics’. These are spread over the soil, plants are put into holes in it and the fabric is covered with gravel or bark. I hate this and it rarely works well. If the area is not flat the bark moves and exposes the fabric. You cover the soil so you cannot improve it with compost or plant food. Creeping plants cannot root into the soil and spread naturally and you can’t add plants or bulbs. The perennial weeds you have smothered will grow through the planting holes and swamp the plants. It just looks awful. It is fine in a supermarket car park but not in a garden.
So remove the weeds before you start and add organic matter to improve the soil.
Spacing depends on how long you want to wait for the soil to be covered and the vigour of the plants. If using shrubs like cotoneasters and creeping conifers spacing can be about 80cm. For smaller plants like ajuga and Vinca minor 30cm is better.
Some plants grow fast and cover the ground quickly but they die out in the centre after a few years – such as ajuga and lamium. To maintain their good looks they need clipping over once a year and mulching with compost so they can root into this and maintain their good looks.
In most cases it is best to buy small plants and plant them closely to produce effective, dense cover most quickly.
I need to mention ground cover roses. What could be lovelier than a carpet of roses full of fragrant flowers? Unfortunately they rarely grow densely enough to smother weeds and nothing is worse than weeding among ground cover roses (apart from weeding under holly bushes) and I write from experience. The FlowerCarpet ® roses are great and very healthy, though have little scent, but though these are the best for the purpose, they are not ideal ground cover, most being too tall. They are great garden plants though.
My favourite plant for shade is Pachysandra terminalis. It will grow in dense shade and only grows to about 15cm high, spreading slowly. It is not exciting but will live and grow for decades with minimal care.
Lamiums are useful and almost evergreen. Their flowers are very attractive to bees in spring. They thrive in part shade. Heathers can be considered in bright, sunny areas too. They need acid soil apart from the winter heathers which are not fussy about soil pH.
Ajugas are infinitely useful and, being native, are good for wildlife. After flowering, in spring, they send out horizontal stems that root and form dense cover. But they need moisture in summer or they are affected by mildew. Look out for a new series of ajugas in the Feathered Friends ® series which include small leaved and large leaved kinds in novel leaf colours. Add them to your autumn pots and baskets and then move them into the garden in spring.
