- ABOUT US
by Andrew Keys
What’s all the fuss about invasive plants? In a nutshell, invasives are plants from other parts of the world that break out of gardens and spread maniacally through our local ecosystems, threatening native flora and fauna, because the things that keep them in check where they grow naturally don’t exist here. And because of that, invasives out-compete whole communities of native plants, replacing ecosystems that support an abundance of life with communities that support little more than the invaders themselves. You see, where they’re native, plants have evolved alongside other living things for millions of years, and in that time they’ve intertwined in a web of relationships too vast for us to imagine--bestowing food, shelter, and other basic needs on creatures large and small. When communities of invasive species replace native plant communities, that system falls apart.
To preserve our precious local ecosystems, we must fight back. One surefire way to do that is to plant native plants instead of invasive species, and to replace the invasive species in our gardens with natives.
If there’s one invasive plant my clients always ask about, it’s burning bush (Euonymus alatus). Beloved for fire engine-red fall color, it is also one of our region’s nastiest invaders. Fortunately there’s a treasure trove of native shrubs with equal or better fall color. Fragrant sumac (Rhus aromatica) is first—and, relax, folks--this isn’t your scout leader’s poison sumac. It’s a pretty shrub, perfect for hedging and tough enough to grow anywhere. (If it’s groundcover you’re after, the variety ‘Grow-Low’ works great; otherwise, go with the species.) Another good choice is Virginia sweetspire (Itea virginica), whose range extends just to the Northeast. The cultivar ‘Henry’s Garnet’ is a real treat in fall. But my top pick for native fall color shrub? Blueberries, any and all. Yep, the humble blueberry (Vaccinium species) isn’t just for fruit anymore. It’s an outstanding shrub in the landscape with unbeatable fall color to boot! Berries are beloved by man and wildlife alike, and they come in varying sizes, one of which is sure to suit your garden.
What about shrubs that are colorful year-round? Red- and purple-leaved barberry (Berberis species), popular for their showy foliage, breeds and seeds plain green offspring into the wild across the Northeast. Multiple native alternatives are available in red-leaved cultivars of ninebark (Physocarpus opulifolius) like Diabolo®, Summer Wine®, and Coppertina™. Not only is ninebark native, it’s also thornless, unlike prickly barberry.
Looking to the heavens, a number of maples are invasive species in the northeast, most notoriously Norway maple (Acer platanoides). Fear not, because three native maples will fill the bill: red maple (Acer rubrum), sugar maple (Acer saccharum) and silver maple (Acer saccharinum). If maple just won’t do, sweet gum is an option (Liquidambar styraciflua), and the cultivar ‘Rotundiloba’ comes without the prickly fruit.
Ornamental Miscanthus grasses have gained in popularity, and though varieties that bloom late in the season aren’t a problem, seed of early bloomers often reverts to a parent form, and these plants are invaders. A safer choice is any variety of native switchgrass (Panicum virgatum) or, for smaller spaces, little bluestem (Schizachyrium scoparium). All are tough additions to any garden, and come in shades from blue to red to everyday green.
Last but certainly not least, a devil I battle in my own garden is bishop’s weed (Aegopodium podagraria). I’m baffled to see the showy white-edged variegated form of this invasive plant for sale when infinitely more showy ‘Stairway to Heaven’ Jacob’s ladder is on the market. This selection of native Polemonium reptans makes a tough, exquisite groundcover, and it has blue spring flowers to boot.
Only some states, such as Massachusetts and Connecticut, ban the sale of invasive plants in nurseries, so it pays to know your invaders. Your state should have a list of plants to avoid on the web. For further reading, check out Native Alternatives to Invasive Plants, by C. Colston Burrell. It’s an easy read for amateur gardeners and pros alike.
Andrew Keys is a NOFA Accredited Organic Land Care Professional, whose company, Oakleaf Green Landscape Design, is located in Topsfield, MA.