Years ago (many years ago, pre-Muddy Boots) we would get calls in spring asking us to “turn over” the soil in the homeowners’ “planting beds”. “Turning over” soil meant laboriously digging up clods of soil and then pulverizing them with the point of a shovel. The areas to be turned over were patches of bare earth, usually with a smattering of shrubs or perennials planted in them. The resulting appearance was like that of mulch, but without the mulch.
I think the “turning over” of soil was a carryover from farming, where fields were plowed in spring before they were seeded. People seem to like the look of freshly cultivated soil. In the landscape, though, there was no subsequent seeding – the ground would remain bare. Unfortunately, there was no sound horticultural reason for the “turning over” procedure. The only benefit was that brief, pleasant “freshly plowed” appearance.
Here is a picture I took in 2017 of an area under some pine trees that had the soil recently turned over. You don’t see this much anymore. This picture shows a very poor attempt at this arcane habit, by the way. Below is the picture I took later to show how weeds had taken over. Turning over the soil did nothing to eradicate the weeds – in fact, it probably helped spread them.
Mulch does some good things. It helps the soil retain moisture when the weather is hot and dry. (Unfortunately, it helps retain moisture in soggy, wet weather when you want it to dry out.) It keeps weeds down, and the decomposition over the following year or so is beneficial to the soil and plants. The main attribute is that it looks nice – like freshly cultivated soil did years ago.
The downsides of mulch? Shredded mulch decomposes quickly. Leaf mulch decomposes VERY quickly. Also, it slides downhill.
The main downside is that it perpetuates the idea that outdoors should be neat and tidy like the inside of your house, unless you have dogs.
A mulched planting bed requires some effort to keep it looking good. Grass will want to grow into the bed from the lawn. Actually, the grass will want to grow in whether you mulch or not, but you should be aware that mulch will not deter the grass in any way. Proper edging will take care of that problem. Unsurprisingly, most homeowners lack this skill (although it’s not a difficult one to acquire). Surprisingly, few “landscapers” do such a simple thing very well.
In addition, mulch doesn’t magically eliminate the need to pull or spray weeds. Mulch will prevent many weed seeds from germinating, but if you spread mulch over growing or dormant weeds, they will just grow right up through the mulch. Also, new seeds that fall on top of the mulch will germinate. Every single Norway maple and silver maple seed that falls on your immaculate new mulch will sprout into a baby tree. The weeding skill required is minimal. Just pull or spray everything – there is no need to know plants!
There is a movement afoot to replace broad expanses of mulch with ground-covering plants. In exchange for a larger initial investment, you would save by not incurring the expense of re-mulching every year.
A disadvantage to the planting approach is that you would have to be better at weeding. Whereas weed control in mulched beds can be done by less-skilled homeowners and grass-cutters, weed control in beds with ground-covering plants requires some expertise to be able to identify and target the plants that are weeds.
Weeding is easier if you use a small plant palette of three or four varieties. Even easier is the smallest plant palette – the monoculture. Just pull anything that doesn’t look like that one plant!
Broad monocultural expanses of pachysandra, vinca, and wintercreeper (euonymus) have been around for a long time, and these groundcovers look much better than mulch. These monocultures are not without their own problems. Certain insects and fungi can be very serious pests, especially on pachysandra and wintercreeper. Another maintenance issue is keeping the lawn grass from growing into the groundcover. This is especially a problem in sunnier areas where the lawn is more vigorous. It’s a simple maintenance procedure, but it must be done regularly.
The new idea here is to plant a mixture of different plants, rather than a monoculture. Use plants that are low-growing and well adapted to site conditions (sun, moisture, tree roots, etc.). The individual varieties are then free to spread, multiply, and compete against each other for garden real estate.
In shade, consider planting oak sedge (a native woodland grass-like plant), epimedium, sweet woodruff, and creeping phlox. For a neater appearance, give the oak sedge a hard haircut on a warm day February or early March before the new foliage starts to grow. This is the same operation that you do for your ornamental grasses, but it has to be done earlier to beat the much-earlier start of spring growth.
In sun, consider prairie dropseed (a native prairie grass) mixed with a few spreading flowering perennials like Zagreb coreopsis and sedum. Prairie dropseed has soft flower stems that grow to around 30”, above 18” mounded foliage. Sun plants probably should be cut down (again, for appearance reasons, not horticultural ones). Feel free to leave the cut-off dead stuff on the ground – cut if up into smaller pieces if you want.
Don’t worry about precise plant placement. Plant things in small groups and let them grow into and amongst each other. Also, don’t obsess about blowing all the leaves out of the planting areas. Personally, I leave the tree leaves until spring, and then just spread them around with a leaf rake to eliminate the areas of excess accumulation.
1 thought on “The future of mulch, or what to do with barren soil in the landscape”
Thank you, Steve, for sharing your informative blog post on the future of mulch and how to deal with barren soil in the landscape. I found your insights on the benefits of organic mulch, as well as the potential drawbacks of traditional mulch, to be very helpful and thought-provoking. Your suggestion to use compost or other organic materials as a mulch alternative is a great idea, as it not only helps to improve soil quality but also provides nutrients for plants and reduces waste. One question I have is how do you suggest dealing with pest and weed control when using organic mulch?