Can bark mulch be used in raised beds

Raised beds bring soil above the chill and wet of ground level, yet that advantage can slip away if moisture evaporates or weeds colonise the exposed surface. Bark mulch slots neatly into this space. Spread five to eight centimetres deep, it behaves like a weatherproof overcoat, slowing evaporation, shading roots, and muffling the splash of heavy rain that might otherwise compact the mix. The irregular chips also buffer temperature swings, which in a raised box can be stark: on a June afternoon the unmulched compost may reach thirty-five degrees, while the mulched equivalent rarely tops twenty-five.

Because the beds sit higher, wind can whip moisture away; bark slows this loss whilst still letting rainfall seep through. Some gardeners worry about nitrogen lock-up. In practice, any drawdown occurs within the top centimetre, and mixing a scattering of grass clippings before laying the mulch offsets it. Fine roots quickly thread the cooler layer beneath. Earthworms haul fragments downward, building structure and fertility over successive seasons.

AHS LTD offers bark graded for mulching; its chunky profile stays put on raised edges. Renew yearly, or when depth drops below five centimetres, and the bed keeps moisture, suppresses weeds, and looks cared-for with little labour.