Too Much Mulch - Tightening Up Your Garden Design

In my college days, I spent a summer working for a suburban landscaping company. I probably split my time equally between commercial projects (read: boiling hot parking lots), residences (where backyard pools taunted me while I worked), and the company's remote nursery facility (which was nice, because the hour drive each way was on the clock).

I admit it's taken me a while to shake the style of planting we practiced, which when I look around now, I see is pretty much the norm for most homeowners: individual plants isolated, often arranged in rows, surrounded by a sea of wood mulch.

Close your eyes and picture a bank parking lot. Along the edges, there's probably some three-foot high shrubs six feet apart with a stretch of black or red mulch in between. Maybe in the front, the bank sprang for some bedding annuals, spaced exactly one foot apart. And maybe if it's in Montgomery County, PA, I planted those shrubs way back when. Look around your neighborhood, and you'll see something similar in many people's yards.

I mean, I get it. Mulch is a lot cheaper than plants, doesn't take much labor to spread, keeps the weeds down, and looks fairly tidy, at least for a while.

But when you find gardens that really move you, you'll start to notice something: Look how little mulch you're seeing. The plants are massed together, and there's very little visible mulch and no visible bare soil.

Aromatic aster and coral bells in a compact mass at Mt. Cuba Center.

Not only is this more aesthetically pleasing - you want eyes to be drawn to the plants not the mulch - but it's better for the plants and the wildlife that depends on them. It allows the plants, when chosen and sited well, to form mutually beneficial plant communities. And by preventing sunlight from reaching the ground, you keep the soil from overheating and drying out and prevent weeds from germinating (mulch itself performs this function, but not as well - I've seen plants referred to as "green mulch" by some writers and designers).

When I look around our yard at some of the plants we've installed since we moved in, I cringe at how far apart I planted some of them. It was just how I was used to doing things, but it doesn't give the pleasing effect of a naturalistic plant community. And truth be told, a lot of plant labels even specify too much separation. You can research spacing online, and if you see a range, it's not a terrible idea to err on the low side of it. In our garden, we're transplanting some plants that are too far apart, and filling in some of the gaps with new plants, but it's been a challenge to go from "here's a cool full-sun plant, it would look nice here in this sunny spot" to a more thoughtful approach. At one point, I planted three little bluestem grasses. I separated them by the distance specified on the label, and put them in an orderly line. After a few years, they look like they're in formation. This spring, I'll be dividing the clumps and replanting them into an amorphously shaped mass.

Frankly, when you bring home an expensive trunk full of plants from a garden center or native plant sale, it can be bit depressing at first when you realize how little garden space they'll actually take up. But you're much better off using them to form a compact, well-thought out mass of plants than to spread them too far out to fill your garden bed.

And you still need some mulch, especially when you're establishing new plants that haven't fully filled out yet. But if you resist the easy temptation of building out a mulch bed with a few plants and instead aim for a thriving plant community, your garden will look better and be much more functional. 

Top photo by Jesus Rodriguez: https://www.flickr.com/photos/jmrodri/8123760212/