Mulch in March

Cherry Butler


A mulch is a soil covering of thick organic matter, such as bark or inorganic membrane, which helps to control weeds, keeps in moisture and retains soil structure.

Why mulch now!?

It looks nice and is better to walk on than bare soil. It also keeps annual weeds at bay (by smothering them) and helps reduce evaporation, keeping valuable moisture in the soil and protecting it from summer sun. Mulching also keeps plants clean (preventing soil from splashing on them in the rain), provides an excellent habitat for soil fauna and can feed the soil (depending upon material). It’s also a great way of recycling and composting and essential for reducing maintenance!

Choice of materials

Think carefully before using weed membrane; it’s an excellent solution for under gravel; large areas awaiting planting like an allotment. But don’t cover your whole garden in it because weed seeds germinate through it and you end up with a bigger problem! Fresh bark and wood chips can rob the soil of nitrogen; it is better to choose products already been composted. Fresh manure can be too strong and burn young stems, so ensure it’s well rotted. Spent mushroom compost contains lime so beware of this around acid-loving plants such as rhododendrons and camellias. Garden compost can spread weed seeds and slugs but we should all be composting kitchen and garden waste and returning to the soil (vis. my November article). All gardens benefit from the addition of organic mulch like manure or garden compost every year, ideally twice a year.

Cathie’s garden army and consultancy

Cathie can spend half a day in your garden identifying plants, advising on planting and design as well as helping you with tasks such as pruning. Lost control? Cathie’s qualified garden army can transform your garden in a day following a consultancy. New for this year, ask Cathie about small and exclusive RHS groups for dedicated students! Email [email protected], visit and follow Cathie’s Gardening School on Facebook, Instagram and Twitter.