Blanket the Ground With Groundcovers

For some reason groundcovers have been rattling around in my head for several weeks.

Maybe it’s because neighbor Nancy seems to be forever planting them and yet with all her planting they never seem to cover the ground. Her plantings are spotty, and it’s as if each plant is a specimen on its own instead of being a groundcover. So while each of her plants is marketed as a potential groundcover they are really isolated plants covering small pieces of ground.

Then there’s my property. I have areas where I’ve purposefully added plants with the sole purpose of covering the ground. Maybe nothing else would grow there, maybe other plants can push up through the cover but choke out the weeds or maybe it’s lawn. Yes, our lawns are in every sense of the word a groundcover.

There are groundcovers that work really well in wooded areas. There are groundcovers that will do well in nearly pure sand (seaside Artemisia among them) and regrettably there are groundcovers that can be terribly invasive and for many it’s the pure nature of some groundcovers that lend them toward invasiveness. There are also groundcovers that feel wonderful under foot and groundcovers that have incredible colors, scents and yes, even fruits. There are evergreen groundcovers as well, so these plants can be both prostrate shrubs like the creeping junipers and many of the low bush blueberries that will only grow 8 to 10 inches tall.

The key idea in choosing a groundcover is to know your soil, light and exposure and be clear about your expectations. Will your groundcover need to be constantly maintained? Will it want to creep and sneak from where you planted it as it seeks to cover more ground? What’s the plant’s reputation? Is it reliably hardy, salt tolerant and long lived? Are there known disease or insect problems? Your landscape designer may like and suggest this or that, but does he or she have real life experience with what they are specifying for your landscape or are their designs just book learned?

A number of years ago a “new” plant came on the scene that was touted as the dream plant of groundcovers. Houttuynia cordata was suddenly the rage and everyone was planting it. Also known as the chameleon plant, it tolerated shade, spread easily, was very winter hardy and was available at every garden center. It was a horticultural marketing miracle — that turned into a disaster.

Reports started showing up several years after many gardeners planted the chameleon plant. It became rampant in most gardens, and gardeners from New York to Ohio, Illinois, Missouri, Virginia, Michigan, Massachusetts (Cape Cod in particular) were giving it a rating of 1 out of 5 stars. The common theme in the comments on the Missouri Botanical Garden’s plant database was “DO NOT PLANT IT!” So, do your homework.

Then there are experiences like the one I’ve had with Lamium. This plant is a well-known and reliable groundcover available in several varieties. In 2007 I bought a couple of plants of Lamium “Anne Greenway,” which is a common Lamium you can find at many garden centers. I wanted to use it in a fairly shaded area at the bottom of a stone wall on the shaded side of some tall lilacs. The silver and green foliage with attractive pink flowers filled in nicely and over the years it ventured beyond where I had intended it to grow.

The plant was easy to thin and control but it had to be “managed” on an annual basis to restrain its “mildly” wandering habit. It seems to be the nature of many of the herbaceous groundcovers. Late every spring we’d edge the planting and dig where necessary with the cut and surplus pieces going to the compost area. Well, some rooted, fell in love with their new digs and began to spread. Lamium now covers an area of about 100 square feet, but in this isolated utility area of the property it’s just fine. It covers the ground well, and I ignore it. But, somewhat mysteriously, it’s also shown up in a few other spots in the woodland garden 150 feet away. No big thing, just be aware.

And of course I love to see gardens and paths where thyme is used as an edger between the pavers and along walkways. I’ve tried a number of times to get several varieties of thyme to grow along my flagstone path, but it never worked. Interestingly though, I’ve driven country roads upstate where thyme covers acre after acre of flatland where the soil is poor and dry and the thyme thrives. That should give you a strong hint. And the sight of acres of thyme in bloom is pretty remarkable. Sunny, hot, dry and thriving.

Like the idea of groundcover among and between your walkway or pavers. Keep in mind that these objects can get very hot in the summer, making your groundcover choices somewhat limited. There is help, though, at a website you might want to look at before you do your shopping: stepables.com.

I was hiking on an abandoned farm that hadn’t been cultivated in nearly half a century. There was a farm pond that was fed by a natural spring about 1,000 feet away. Where the spring stream met the pond there was a difference in elevation of about five feet, and at some point the farmer lined the surrounding area with stones, creating an unintended rockery. Among many of these stones I found a wonderful little cottage pink (Dianthus plumarius) and I wanted some in my garden. Well, you can’t always get what you want, but if you try real hard …

I went back a number of times and finally caught the plant when the seed was ripe and collected some. It germinated easily, but it took me close to five years to find a place on my property where it took hold. It’s now, finally, a groundcover under a paper birch. It needs pretty perfect drainage, as I learned from several failed plantings, so it’s not planted into the native soil but in amended soil that drains quickly and set in a bed above the ground in a trough surrounded by cobbles.

You may not think of Dianthus, or pinks, as a groundcover, but the gray/green shoots create a mat, which sends 10-inch stems up that are covered with delightfully scented flowers. It’s easily grown from seed sown indoors in February, and once it finds the right home it will probably outlast you. The plants I found at the farm must have been originally planted ages ago.

And in the shade? What groundcovers can be safely planted in the shade? I’ve got two that might interest you. Neither of my choices is Pachysandra but despite its plebeian reputation and its questionable status as being invasive, it’s not. It’s a ground cover! One of my picks is Polygonatum odoratum “Variegatum” and the other is Salvia kayamae, or the Japanese yellow sage.

If you remember Martin Viette’s nursery in Old Brookville, they had a well-established propagation block of the Polygonatum (dwarf variety) growing in their woodland. Each spring root sections would be dug, potted and sold. This dwarf, false Solomon’s seal is certainly a spreader, but in the wooded garden or at the woods edge this plant can be an attractive groundcover growing up to 18 inches tall. It flowers early so it’s an early pollinator plant and along with its hanging white flower and variegated foliage it has no insect or disease issues that I’ve seen in two decades. It doesn’t wander and jump around, but it does spread and may need some annual management.

The Japanese sage was an unexpected surprise. I’d bought one plant from Plant Delights in 2018. It grew to nearly 15 inches tall and as wide and seemed to enjoy the shady spot in the woodland under the hemlocks but at the lawn edge. It began flowering in September and continued into October. The next year it came back but was taller and it got knocked down by a passing deer. Much to my surprise and delight the stem sent roots to the ground at every leaf node and the following year my single sage was now dozens of them as offspring rootings from the fallen parent.

The plant or plants now cover an area of about 100 square feet in and among the dwarf false Solomon’s Seal so there is the early foliage and flowering from those plants followed by the sage and its fragrant yellow blooms in the early fall. Mother Nature took hold and did a great design and integration. Thanks MONA.

There are some incredible opportunities here for the gardener that’s curious and yet careful. From the dunes to the walkways and paths to the woods, there are groundcovers to delight you all. Keep growing.