Starting a new native garden from scratch can feel overwhelming, especially that blank page. Fortunately, there is one technique that will get you designing immediately, ease maintenance, and imitate patterns seen in nature: the groundcover matrix. I use a matrix in almost every garden I design and I hope to inspire you to do the same.
Native plants often move around our gardens over time. A patch of blue mistflower (Conoclinium coelestinum) might evaporate from one bed and materialize in another over the span of a few years. Some plants will fade away and others will volunteer from seeds dropped by birds. If native plants move around as it suits them, why does it matter where we first plant them?
Well consider the first few years of a native garden. When you start with bare soil, it will take some time for the garden to fill in and begin resembling a low meadow or shady verge. If you plant in a geometric pattern, the garden will not only look intentional to friends and neighbors, you’ll also have an easier time recognizing new growth in the spring and distinguishing it from undesirable weeds.
Your Hardest Worker
Native plants have distinct jobs in a wildlife garden, and groundcover plants work harder than any other group. While the term groundcover sometimes lumps together any plants that creep across the ground, in the native gardening context these plants must be relatively low-growing and semi-evergreen so they can defend the ground from weeds in early spring. They generally bloom early as well, which provides forage for the first bees of the year. Perhaps most important to the gardener, these plants apply root pressure to taller, later-season plants, causing them to grow deeper and stand stronger. This is why dense meadows stand straight and tall.
Laying Out the Matrix
When I design a matrix, it looks a lot like a checkerboard. I divide the garden into one foot squares and make every other plant a groundcover species.
If you’re doing the math at home, you may realize that I’m calling for a lot of plants (one per square foot of garden). While this may seem like a lot, and potentially cost a lot, consider how closely native plants grow in the wild. Two plants can grow quite happily with only a centimeter between them. The density I suggest is a good compromise, as your plants will not start too far apart and can fill in the rest of the way over the next few years. As the ground becomes fully enclosed, new weeds will drop close to zero.
What About Massing?
Experienced gardeners of any style may notice an omission so far, that of massing. In contrast to a matrix, mass planting is the practice of planting a large number of one species together, so that visitors can easily spot large clumps of similar plants, which gives a sense of order. To me, this technique has major drawbacks for the native gardener.
Imagine a five-square-foot area planted entirely with aromatic aster (Symphyotrichum oblongifolium). In late summer we would see a huge mass of purple flowers blanketing that area, alive with bees and butterflies. But in March through May, the ground might be completely bare with only a few remnant stems or the first asters poking up through the dirt.
Those late summer asters would also lay flat on the ground, as no competing plants had forced them to grow tall and strong. The garden would lack a connection to its wild counterpart, as plants rarely grow in a monoculture in the wild. This in turn would bring in a heavy crop of winter weeds unless mulch was applied, a chore that must be repeated each year, forever. I have seen this style of planting fail again and again.
Filling in the Windows
Fortunately, the matrix offers all of the benefits of massing without any of the downsides. In the windows between the groundcover plants, I place my seasonal interest and filler plants. Seasonal interest plants are those that most gardeners think about first: taller plants that create large numbers of flowers in the summer. Fillers are also later blooming, and they tend to appear and disappear over time, as I mentioned earlier with blue mistflower.
If you want the same effect as a mass planting, consider a pop, which I define as three or more of the same plant in adjacent one-foot-square windows. This is great for plants like butterfly weed (Asclepias tuberosa), which, in natural environments, tends to pop up in small clumps among other plants.
Groundcover Species
Here are some groundcover plants for sun and shade to get you started.
Sun-loving:
- Golden alexanders (Zizia aurea)
- Sundrops (Oenothera fruticosa)
- Virginia strawberry (Fragaria virginiana)
- Plantainleaf pussytoes (Antennaria plantaginifolia)
Shade-loving:
- Golden ragwort (Packera aurea)
- White wood aster (Eurybia divaricata)
Jimmy Rogers is an avid Laurel gardener and owner of Laurel-based Vibrant Gardening LLC. Send your native gardening questions to him: nativegardenguy@gmail.com.