'Toupee' Plants Fix Landscaping

By Laurie Casey
The Morton Arboretum

Towering pines or dense hedges come to mind when we think of “evergreens.” But don’t forget the low growers. Evergreen ground covers are versatile plants that can solve hard to mow areas, like slopes and around trees, and provide more interest and thicker cover than turf grass. Think of them as the toupees of the plant world!

Last month we talked about the damage that string trimmers and lawnmowers can do to trees. While The Morton Arboretum recommends making a no-mow zone around a tree with a layer of double-ground mulch, filling in with ground covers can work, too.

You can plant evergreen ground covers now in the fall and enjoy their green hues this winter. We’ll highlight two native ones, Christmas fern and coralbells. They’ve adapted to our climate over centuries, so they are easy to grow and hardy.

Christmas fern, a shade-loving native, thrives under trees. It’s also a perfect companion to spring wildflowers and bulbs because its lance-shaped fronds provide attractive cover for dying bulb leaves. There’s only one possible downside: heavy snow can break the fronds, but even then, it’ll send up new growth in spring.

Coralbells, also called alumroot, is a native that forms 12-inch tall, 2-foot wide mounds of heart shaped leaves. This is a favorite of Doris Taylor, the Arboretum’s Plant Information Specialist. Depending on the cultivar, small red, pink or white bell-shaped flowers hang off a long slender spike in late spring to early summer. “Coralbells require well-drained soil and are shallow rooted, so don’t plant them too deeply,” advises Taylor. She also suggests a 1- to 2-inch layer of mulch to keep plants from frost heaving during the late winter freeze and thaw cycle.

Many people are familiar with common periwinkle and Japanese pachysandra. These ground covers are easy to find at most garden centers and easy to grow. They, along with euonymus wintercreeper and spreading common juniper, handle slopes like expert skiers. Wintercreeper can be pruned if it becomes too aggressive. Spreading common juniper likes full sun, so it doesn’t do well under trees.

Other great evergreen options include Lenten-rose, Siberian-cypress and candytuft. You can find these and more ideas in a free leaflet called “Evergreen Ground Covers.” Visit www.mortonarb.org, and search for the pamphlet by title.  

If you are planting under a tree, be mindful that the new plant will be competing with your tree for water and space for roots. To lessen stress on the tree, don’t dig around too much, advises the Plant Clinic’s Donna Danielson. “These ground covers spread pretty easily,” said Danielson. “Plant them sparsely and let the roots duke it out for themselves.”

Spread wood chips to keep down weeds and retain moisture while ground covers fill in. And don’t forget to water thoroughly periodically, as the tree and new plants will be vying for the same moisture.

Next time you notice a bald spot in your yard or want to protect your tree, keep the grass seed on the shelf. Instead opt for one of these evergreen carpets that will glow green this dreary, gray winter.

Glad You Asked

Q. What ground cover can I use under my pine tree?
A. It’s difficult to grow anything under pines and spruces, due to their dense shade. For these trees, mulch or let pine needles cover the ground.

Q. Will I damage my tree when I plant something underneath?
A. Any time you cut tree roots, you damage the tree. To minimize damage, start small. Plant quart-sized plants rather than gallon-sized ones, recommends Taylor. And move your planting hole rather than cut into a large root, especially if the root is more than 2 inches across. Plant under one side of the tree this year and finish the other side next year.

At the Arboretum
Get the dirt on what to plant for fabulous fall color in “Landscape Plants in Late Fall” 10 a.m.-12:30 p.m. Saturdays Oct. 18-Nov. 1. $75 (discount for members). Registration now open. Call (630) 725-2468.

Laurie Casey is a staff writer for The Morton Arboretum.