Should I remove old mulch before adding new bark

Each spring gardeners face the same dilemma: is it wise to scrape away last year’s mulch before spreading fresh bark, or does that waste time and nourishment?

If the existing layer has matted into a quilt more than eight centimetres deep, removal or at least raking helps oxygen reach the soil and prevents stems from staying damp. It also exposes grubs and weed seeds, giving birds a banquet before the covering arrives.

Where the old mulch has thinned to only two or three centimetres, however, it is better to leave it in place. Those half-rotten fragments are already halfway to becoming humus, and burying them under a fresh blanket accelerates decomposition while suppressing weeds. Scratch the surface with a fork to break any crust, then top up to the recommended five-to-seven-centimetre depth.

Whichever route you choose, match the new material to the age of the bed. Young plantings appreciate a shred that knits with last year’s crumbs; mature shrubs accept coarser nuggets that linger longer. AHS LTD supplies both grades, so you can tailor the mix without combing stockists. Aim to refresh the surface in winter or early spring, before weeds wake and while moisture still clings to the earth.