Dos and don’ts of mulching

It’s March, so let’s talk about mulch madness.

There’s a tiny bit of controversy among some gardeners about whether to cover the soil with wood products, fueled by the thinking that chopped leaves are a more sustainable choice. For the most part, the leaves can come right from your yard (or your neighbor’s), eliminating the carbon footprint of processing scrap wood products into shredded bark, chips or fines, shipping to garden centers, and your driving there and back.

Bulk mulches come in various colors, depending on what they are, such as pine, mixed woods or cedar. (C) Photo ejkrouse/depositphotos.com

It’s just something to think about. Chopped leaves decompose faster than chips or shredded bark, but each improves soil health, conserves moisture and moderates soil temperature in the root zone. I agree the wood mulches provide a refined, finished look.

Mulches labeled as pine fines or shredded bark tend to decompose more quickly, also. Chip mulches work well around trees and shrubs, but make flowerbeds look clunky. Chip mulches may float away during heavy rains. You can buy mulch in bags or bulk. And no, wood mulch does not attract termites.

A light raking of wood mulch in spring gives it a fresh look. Mulch does not have to be applied every year.

Not in My Yard

That would be stone or rock mulches. When I moved into my house, there was a 4-foot deep and 40-foot wide bed of gravel mulch across the front. That first summer, wheelbarrow-by-wheelbarrow, I carted the gravel across the street to my neighbor’s driveway. She was grateful to have some of the low spots in her gravel drive filled in. I was grateful to have a place to dump the gravel.

You can’t just dig the gravel into the soil like you can wood mulches. It has to be moved to plant anything. Stone mulches tend to retain heat, which can scorch plants.

I also dislike the mulches made from ground up skids and dyed a grotesque orange-red. The skid mulches take forever to decompose, so they are not all that great for soil improvement. And they are ugly. In general, I’m not a big fan of dyed mulches, mostly because they don’t look natural.

Landscape cloth is another product banned from my landscape. When I bought this house, that cloth was everywhere. It is a waste of money and does little to stop weeds, which will seed atop the landscape cloth, sprout and grow.

Volcano mulching is bad for trees. The mulch keeps the bark moist, opening up the tree to insects and disease. (C) Photo Jo Ellen Meyers Sharp

Practices to Avoid

When mulch is piled up against the trunks of trees, it’s called a volcano. Don’t be fooled by this practice, even though you’ve seen landscape maintenance crews mulch high around trees. It’s a bad practice. The mulch retains moisture against the bark, opening it up to insects and disease.

Mulch that’s too thick – anything over about 2 to 3 inches deep – is not good, either. This practice draws some of the surface roots of trees or shrubs into that mulch mound.

Don’t be skimpy with how large the mulched area should be under a tree. Some advise mulch should go to the tree’s drip line, but for many of us, that would be the entire yard. Try to strike a decent proportion of mulched area to tree size. Many times, the area is too small and even when planted, looks like a tight chocker rather than a lovely necklace jeweled with plants.