Consider green, or living, mulch as an alternative to wood mulch
WRITTEN BY STEPHANIE BOUCHARD
There’s something particularly enjoyable about bark mulch in the landscape, said Caleb Davis, landscape designer and owner of Songscape Gardens, a landscape design and build company in Bar Harbor.
“I remember getting great satisfaction out of a nice, very neat, clean garden that’s freshly mulched,” Davis said. But Davis, like many gardeners, has come to appreciate a more richly planted and layered landscape created with green mulch.
Green, or living, mulch is a layer of plants under taller plants, trees, and shrubs taking the place of bark mulch in the landscape. Think hay scented ferns under trees. Like bark mulch, green mulch works to suppress unwanted plants (sometimes called weeds, depending on your perspective) and retain moisture, but it offers additional benefits that increasingly appeal to home gardeners, say Davis and Cathy Rees, cofounder and executive director of Native Gardens of Blue Hill.
From a practical perspective, using a living mulch that’s matched to the landscape conditions means less work for gardeners over time, said Rees. Gardeners plant once instead of having to purchase bags of bark mulch and apply those to their landscapes every year. Once established, green mulch is mostly self-sustaining, needing few, if any, interventions from gardeners.
A living mulch also gives gardeners the opportunity to accomplish one of their favorite things: putting more plants in their gardens. And, depending on the plants chosen, can provide additional interest in the garden, said Davis. Consider, for example, sedges or phlox planted under peonies that bloom when the peonies are not in flower.
“Plants have evolved to grow in community with each other and plants are, for the most part, happier in that type of situation,” Davis said. “You can definitely underplant a tree with perennials and grasses or sedges in a way that’s beneficial to the tree. They’re not going to be competing for resources, but instead actually sort of providing a mutual benefit. That’s what we see in nature.”
Like in the wild, an ornamental garden using a green mulch becomes a multilayered landscape that not only is pleasing to the eye but supportive of life.
“You’re sort of expanding the area of food and habitat available for pollinators and insects,” Rees said, “and then subsequently, food for mammals and birds on up the food chain.”
Planting a green mulch is not as simple as spreading 10 bags of bark mulch around perennials in the garden. Selecting specific plants and combining them appropriately are key to creating a successful living mulch, say Davis and Rees.
“There’s definitely a lot of benefit to understanding the situations in which plants have evolved and using plants accordingly,” Davis said.
Using native plants for a living mulch is a great idea simply because they’ve evolved to thrive in our landscape and in tightly knit communities, which make them ideal as a green mulch as they won’t be subject to fungus or disease. That said, green mulches don’t require the use of native plants, Davis said, so gardeners can explore and experiment.
When selecting plants for green mulch gardeners should match the plants to the site conditions, Rees said. Plant guides, like the one in the resources section of Native Gardens on Blue Hill’s website, provide information about the soil conditions specific plants thrive in.
Home gardeners can also talk to their local garden centers for advice, or hire a professional who has experience in designing landscapes with ecological horticulture principles. There are also a number of good books and online resources. Davis recommends Roy Diblik’s book “The Know Maintenance Perennial Garden” and Thomas Rainer and Claudia West’s book “Planting in a Post-Wild World.” Both are good resources for home gardeners wanting to experiment with living mulches.
