Persistent weeds are difficult to eradicate just by digging, and shallow-rooted shrubs do not like the ground beneath them being disturbed. But applying a layer of mulch in spring is a good eco-friendly way of tackling weeds. It is a particularly useful method if the roots of the weeds have become entwined with the shrub's root system, so that weeding would damage the shrub.
Use organic materials such as bark mulch or wood chips, which decompose slowly. Spread them in a layer a couple inches thick, making sure the mulch does not touch the stems of the shrub. Bark mulch draws nitrogen out of the ground and deposits tannic acid, so it is unsuitable for newly planted shrubs, but it will not harm established shrubs. If a nitrogen deficiency occurs (noticeable yellowing of the leaves and stagnating growth), the imbalance can be corrected with fertilizer.
Mulch with grass cuttings only if you are sure they are weed-free, and leave them to wilt first or they will attract snails.
An organic mulch will eventually decompose and need replenishing, and it does not always completely suppress weeds. But there are other materials that can be used. A layer of newspaper or black polythene sheeting is one alternative; the unattractive appearance can be masked with a layer of bark mulch. Special mulch matting made of hemp or flax is also available, or gravel can be used. They all work in the same way. Any weeds that have already grown that are covered by the mulch are deprived of both light and air and eventually die, while weed seeds do not have the chance to germinate.
Alternatively, plant shade-loving groundcover plants with decorative foliage beneath shrubs – such as purple-leaved varieties of bugle (Ajuga reptans) or various types of variegated white dead-nettle (Lamium album). Weeds will no longer be able to thrive once these plants have carpeted the ground between the shrubs.
The Reader’s Digest Association, Inc./GID
Organic materials, such as wood chips, can efficiently suppress weed growth.
