Persistent weeds, such as ground elder (Aegopodium podagraria), couch grass (Elytrigia repens), stinging nettles (Urtica dioica) and brambles (Rubus spp.), are often widespread under shrubs and trees. They become tangled up in the root systems, making them very difficult to eradicate. They will compete with shrubs and trees for nutrients so must be removed.
One of the best ways to tackle weeds is the most old-fashioned; simply pull them out, preferably on a dry sunny day in spring, when any remains left lying around will wilt quickly. An easier and less time-consuming option is to mulch. Applying a layer of mulch in spring is a good eco-friendly way of tackling weeds; the lack of light and air simply kills them. Below are three ways for dealing with weeds under shrubs and trees.
Try a bark mulch or wood chips, which decompose slowly. Spread them in a layer a few inches thick, making sure the mulch does not touch the trunk or stems. You can mulch with grass cuttings if you are sure they are weed-free, but leave them to wilt first or they will attract snails.
Suppress weeds with layers of newspaper, weighed down with soil or grass clippings or opaque polythene sheeting weighed down with stones. You can also hide these under a layer of bark. You can buy special mulch matting made of hemp or flax, or use a layer of gravel.
Alternatively, plant shade-loving ground cover plants. Good choices are purple-leaved varieties of bugle (Ajuga reptans) or variegated white dead-nettle (Lamium album). Weeds will no longer thrive once these plants have carpeted the ground beneath shrubs and trees. Only do this around plants that are a few years old.