Mulch, much like much maligned compost, is often mentioned in the gardening world but seldom explained. It’s easy to think that mulch is something or other to be put onto the soil unlike compost which is something or other to be dug into the soil. In this month’s article I will be explaining what mulch is, where you can put it and what it is for. Hopefully, you will no longer wrestle with the overwhelming choice of garden centre mulches when all you really want is to buy a bag and get home again a.s.a.p.  The Oxford Dictionary definition of mulch, “a mixture of wet straw, leaves etc” is tantalisingly close but frustratingly vague and it is that confusion that I hope to clear up here.

What is mulch? Mulch is any of the following :- Gravel and shingle, tumbled glass chippings, stone chippings, grass clippings, mulch matting, chipped car tyres, wood or bark chips, straw, leaves, compost, Leca or manure. There are others too but I expect you have got the picture by now. Leca looks a bit like burnt popcorn but is in fact expanded clay granules. Leca helps to stop evaporation from the soil surface but does not retain moisture itself, important in a garden containing drought loving plants.

Where should I use mulch? Use plant based mulch in the flower bed to protect plants that are not fully frost hardy, in the veg garden to protect plants such as rhubarb or berries.  Plant based mulch is also useful for suppressing weeds and retaining soil moisture around the base of trees and shrubs. Use non plant based mulch for decorative effect and in areas such as rock gardens or alpine gardens. Coarse chips suit larger plants, fine chips suit smaller plants.  

What is mulch for? The point of mulch is to either provide a decorative effect, such as around low growing alpines, or to help with weed control, retention of moisture, reduction of soil compaction, frost protection and regulation of soil temperature.

As usual, there are subtleties that you can investigate if you really want to master mulch and all that it undoubtedly has to offer the garden. For more information you can refer to the index in most gardening books or web sites. Happy mulching.