It was serendipitous. For a few weeks in mid-spring, my garden is the tidiest it has ever looked, thanks to an application of mulch/compost that gets put down at the beginning of every gardening season. All the winter detritus magically vanishes, leaving spring bulbs, spring-flowering perennials, and the fresh green emerging foliage of summer perennials, set off by their dark brown backdrop, which looks black, though it’s not. This doesn’t last long, nor would I want it to, but I was just admiring it when I turned to my phone and there was a New York Times column by Margaret Roach in praise of mulch.
It’s an interesting column which comes down in favor of the dark, finely shredded product I’ve always used, mainly for looks, but Roach also notes that, because it’s aged, it’s less likely to steal nitrogen from the soil (a controversial issue in horticultural circles). She prefers it for formal beds; so do I, and, given my urban courtyard garden and the surrounding architecture, all my beds are formal. I can’t use shredded leaves as many do; Roach employs these in her vegetable beds.
I won’t repeat the whole article—I heartily recommend a subscription to the Times!—but there is also a good explanation of how mulch can build soil from Roach’s expert, horticultural professor William C. Fonteno, of North Carolina State University.
Here’s one final quote: “Mulch contributes to weed control by blocking the light that some unwanted species need to germinate. It also forms a barrier that prevents weed seeds from getting a foothold.”
Sounds simple, right? But I rarely hear gardeners talking about mulch to control weeds, at least not around here. They’re mixing soap with vinegar, they’re pouring boiling water, they’re laying down cardboard and tarp. They’re not pulling and mulching. I have been doing that for years and have seen significant weed reduction. In addition, my perennials have been able to spread into mulched areas, which doesn’t present the same barrier as cardboard. And isn’t stupid, like vinegar.
Over the years that I’ve been mulching, I have less and less need to do it, as the areas between plants have grown smaller and smaller. I may temporarily admire the dark backdrop my plants now have, but I wouldn’t want it all season long—and I don’t have it. (The hostas shown at top will cover that space completely.) Also over the years: I’ve noticed that the soil where I’ve mulched is easier to get into.
I don’t know if this was the point Roach wanted to make, but the thing I like about mulch is that the more I do it, the less I need to.
The biggest trick of the lot is to let the plants mulch themselves by cutting them down in situ and leaving the stuff in place. Though some plants do this better than others – hostas don’t mulch themselves very well. Always worth trying though, since if you can access made mulch (as above) you can always top up.
For decades now I’ve shredded and transported about twenty yards of Oak leaves annually from our upper yard to a lower garden we’ve developed. I can say that the once heavy, barren clay soil is now a rich, fertile, well planted space that requires less weeding, or water and is close to self sustaining as far as mulching is concerned. It doesn’t happen overnight but I recommend it.
I was a big fan of mulching until I realized it was harboring sow bugs, which appear harmless but are actually jaws on legs that consume everything in their path. There are no easy answers. Diatomaceous earth keeps them away, but living where water is required daily on vegetables, it isn’t realistic to keep refreshing that stuff daily. It’s a war out here!
While I agree with many benefits of adding finely shredded mulch to the garden (it does improve clay soil after 20 years of annual applications), I find that “living or green” mulches are even more beautiful than bark or composted leaves. According to Doug Tallamy, green mulches provide “soft landings” under trees and shrubs for caterpillars and other insect larvae. That said, a freshly mulched hosta garden is beautiful!
I have used the shredded brown mulch for over 25 years and talked to many, many people about the advantage of mulch, including weed suppression. On my city lot, the entire front and long north side were mulched,..no grass, just plants, trees, shrubs and mulch. For the last 10 years I only weeded 3X a season. Once in the late spring, once in mid summer and finally late in the fall. The mulch had to be renewed in spots every year as I added, moved, etc. plants or areas simply became thin due to natural activity. And as you say, the more you mulch, the less you weed.
It’s an absolute must in dry windy areas. Record temperatures and serious drought conditions last summer yet my garden sailed through without extra water. Can mean the difference between life and death.
Well, I am keen on reading such articles and I always compare with other top authors. Strange as it may seem, but you’ll find a really extraordinary opinion on this point on compacom.com. I don’t know which one is true. Read it yourself and make up your mind which side to take.
Elizabeth, Great piece on the value of finely shredded dark mulch. I love the pristine look of a freshly mulched garden bed too and the cedar smell that lingers for a day after it is placed down. I know it has its detractors, but for me and as a member of the volunteer gardeners in the public gardens in the Village of Williamsville, we can’t wait til our DPW spreads a truckload of the dark stuff! It makes the hours we spend in the gardens less arduous as we weed a lot less and our plants do so much better.
Elizabeth, If you can swing it, I suggest a trip to visit Ann W. for the straight scoop on mulch. Used intelligently it is the gardener’s best friend. If a trip across the pond is not in the cards, contact your local Master Gardeners. They will have all the tips you will need to use it wisely in your area and will be happy to sing the many praises of mulch.
Beware, however, the dyed mulch used by so many landscaping companies (and commercial producers, as well), which may consist of any woody material – packing crates, etc.. Hardly a sustainable product.
Here I’m Georgia I’m trying to cover the ground with living mulch as much as I possibly can, but where plants haven’t matured I either mulch with our local pine straw or pine fines. If I didn’t mulch my bed edges I would spend the entire summer weeding. Southern soil produces more weeds per square foot that anywhere I’ve lived. Sometimes I long for a garden in Ohio!
People endlessly debate every issue under the sun as though there is a single truth for every situation. In my garden, sometimes a thick layer of compost mulch has been beneficial. In other times and places, a thin layer of bark mulch made more sense. My strategy depends upon my soil composition, my climate, and whether I’m growing perennials, or woody shrubs or vegetables. The pro and con arguments about vinegar as a weed killer is a prime example of my point. It’s true that vinegar is not a weed killer. But in dry summer regions, vinegar can be a very effective weed suppressant for gravel pathways and driveways. Maybe we should drift away from one-size fits all mentalities.
The two reasons mulch is necessary in the area of North Texas I live are tied for the number 1 reason to use mulch – soil temperature control and weed control. A close second, or maybe a three-way tie for first place reason is to keep the soil as soft and friable as thick clay gumbo soil can possibly be. Somewhat related to soil temperature is soil moisture. It gets SO DARN HOT here, with rain becoming a forgotten benefit of the past, mulch helps soil to retain what little moisture it has. I just don’t understand why anyone wouldn’t add mulch to their beds. Or their lawns for that matter. A thin layer of compost added on top of lawns is very beneficial.
All that, and mulch does help to dress up beds.
Oops, I hit enter before finishing my name! Sorry. I’m not trying to be anonymous.
Sally
When I do it right, a bed of plants gently overlap, negating any need for mulch. When I do it wrong, and I have a little of this, a little of that, and very little overlap, I feel like it not only suppresses the weeds, but it makes it look better, somehow.
Hope you are okay!
Condolences to the families of Buffalo.