Why it’s good to mulch:
I may well consider myself head gardener whenever I stride out enthusiastically, to ‘get to grips’ with my own green space. However, I’m fully aware that in the hierarchy of my own personal gardening management structure, Mother Nature is most definitely the boss; my boss. She always has been and will be forever more. With this in mind, and as a dutiful and eager student of hers, I look to learn the lessons of gardening and nature, watching closely her every move and action. I am merely a custodian of the green space in which I garden and she reminds me daily of her incredible power and magnificent influence.
One of the most valuable lessons I have learned in the many years I have gardened, both at home and professionally, is the benefit of mulching, the covering of soil with either organic or inorganic matter, which is extremely advantageous to both soil, plants and gardener. And, as always, I’ve taken my cue from ‘the boss’ and nature to emulate this practice in my own garden.
In autumn, especially, and during the course of the gardening year, leaf litter, plant debris, and detritus fall to the ground covering the soil beneath. As the weeks pass into months, and indeed years, this waste matter builds, layer upon layer, serving a number of purposes including protecting the soil from the vagaries of the weather, locking in precious moisture, preventing the establishment of weeds and much more.
Whilst I have a few trees in my own garden, and the odd couple of hundred plants, there isn’t quite enough waste material to optimise the substantial benefits of mulching, so here’s where we, as self-appointed head gardeners, can step in.
Organic mulches:
Organic mulches include well-rotted garden compost, or manure, leaf mould, grass clippings or composted bark which all decompose slowly over time. They are best applied as a thick, 6-10cm layer, in late autumn or early spring when the soil is damp. It’s better to mulch a small area really well than to spread mulch too thinly over a larger area, where its benefits will be largely lost. I’m lucky enough to have space for four ‘Dalek’ style composters, which provide an ample source of mulch. I’ll cover composting very soon in a separate post.
Once the mulch has been applied, it acts as an insulating ‘blanket’ overwinter, protecting the roots of more vulnerable plants, preventing soil erosion during the extreme winter weather and at a time, when are gardens can look pretty sorry for themselves, it’s an attractive, aesthetically pleasing option.
When mulching, especially in spring, keep an eye out for emergent bulbs and perennials, keeping the mulch away from the stems of all plants, shrubs and trees, to prevent stem rot.
An organic mulch provides a valuable food source for earthworms, who will come to the surface and pull the organic matter back down into the depths of the soil. The movement of hungry worms greatly improves soil structure, and the mulch components, once eaten, digested and passed through, add valuable nutrients around the root zones of our plants, whilst providing a further food source for the millions of beneficial micro-organisms, also working busily away in the soil. The resulting top-up of essential nutrients, improved soil structure, and locked in moisture, are invaluable for improved plant growth, meaning less time feeding and watering for busy gardeners.
It's also thought that certain mulches (composted pine and cedar bark), contain compounds which actually repel some pests. And of course, a thick layer of mulch will make it difficult for certain pests to burrow down into the soil to nibble on precious plant roots.
And, the good news keeps coming. During the course of the season, the thickly applied mulch will prevent weed seeds from germinating and growing away, so less weeding, and in the long, hot, dry summers we’ve experienced in recent years, it will regulate the soil temperature down at root level, keeping the root zone cool and moist.
Inorganic mulches:
Inorganic mulches, like pebbles, stones and slate chippings don’t decompose, so don’t provide the nutritional benefits of an organic material, but may still be a worthwhile consideration as they are longer lasting and more durable option. As with their organic counterparts, they also prove beneficial when laid in a 6-10cm layer, locking in moisture, suppressing weeds, preventing soil erosion, regulating soil temperature and deterring some pests.
I love using ornamental pebbles and slate chippings on long-term container plantings, where without them, the soil is more prone to drying out more quickly. Equally, they can be used in borders around permanent plantings, and where the application of regular organic mulches might be time-consuming or troublesome, for example, in an inaccessible spot of the garden. However, do bear in mind that some mulches might look incongruous in the wrong place. Pebbles and slates will look awkward and not practical in a natural, or woodland garden and well-rotted garden compost might not be in keeping with a slick, contemporary garden.
How often should I mulch?
We’ve established that inorganic mulches are a longer-term consideration and that organic mulches will decompose over time. I try to top up my organic mulch every spring, and sometimes, if I have spare, well-rotted garden compost or grass clippings during hot, dry spells spare, I may top up some areas during the season. In this situation, it’s imperative to water the soil before applying the mulch to ensure you’re not locking in dryness.
So, if you're looking for a gardening job over this coming weekend, why not pop mulching at the top of your list?
If you’ve enjoyed this article, or have any questions about mulching, or any aspect of gardening, shout out in the comments below.
Thanks for reading!
I can’t say I paid much attention to mulch pre the internet gardening communities but I’ll be forever grateful for following suit. My clay and ridiculously heavily shale laden soil has benefitted tremendously in fact I was thinking about it when planting out yesterday and the well mulched areas were a pleasure to work and I made mental notes as to where to focus mainly in the coming seasons. I’ll be sparing on my ‘hill’ though; it’s ideal for alpines and low growing acid loving plants and since it takes the full force of the coastal wind that works pretty well. I must say I am ludicrously happy when I can use my own compost and leaf mould. What a terrific sense of satisfaction that brings.
I’m a complete fan of mulching and you explain the benefits so clearly in this article. The soil in my garden is heavy clay. When we arrived, 36 years ago, the garden hadn’t been cultivated so the prospect of creating a place where plants to could thrive seemed bleak. However, my gardening passion grew despite this and as it developed so did my attention to the soil which is, after all, the key to a good, healthy garden. After annual mulching with home made and bought in organic matter I now have a living, healthy, friable home for plants and an army of worms and the millions of micro organisms you refer to. I add mulch to newly planted acquisitions and will happily extol its virtues to anyone who cares to listen - cue some glazed expressions! 😁. I believe I’ve heard you suggest that it’s good practice to, ‘Spend a pound on the soil and a penny on the plant.’ An excellent maxim for gardening success I think.