How long does bark mulch suppress weeds

One of the main reasons gardeners turn to bark mulch is to keep weeds under control, but how long does it really last? When applied correctly, bark mulch can suppress unwanted growth for many months, often close to a year, before it begins to break down significantly. The thickness of the layer is crucial here. A covering of five to seven centimetres is usually enough to block out light, which is what most weed seeds need in order to germinate.

Over time, the mulch will naturally decompose, thinning out and allowing gaps where weeds can begin to reappear. In most gardens, topping up once a year is sufficient to maintain its weed-suppressing qualities, though areas that experience heavy rain or strong winds may need attention sooner.

It’s worth noting that bark mulch works best against annual weeds. Persistent perennial weeds with strong root systems may still push through, though in smaller numbers. The overall effect is a significant reduction in weeding time and effort, leaving beds looking neat and plants less crowded. For those seeking reliable supplies, AHS LTD offers a range of bark products well suited to maintaining weed-free borders season after season.