Released August 26, 2008
URBANA, Ill. -- Your garden's "bones" may provide visual interest and variety from December through March, said a University of Illinois Extension horticulture educator.
"Does your garden have good 'bones'?" said Martha Smith. "This is a winter-design buzzword. Which plants offer a sense of permanence and structure in your garden during the winter? With the big show of flowers out of the way, your garden is reduced to its purest form.
"The skeletons of woody plants provide interesting designs against a winter sky."
During the fall season, many gardeners begin their winter preparation ritual--enjoying fall foliage colors but dreading the inevitable raking to come. Neighbors seem to compete with each other, raking every last leaf off their lawns and then attacking garden beds.
"With blower or special rubberized leaf garden rake in hand, they begin the assault," Smith said. "They pull out the annuals and snip back perennials, leaving a barren 'moonscape' to look at all through the winter.
"In our landscape beds, why not take a lesson from nature where leaves remain where they fall and many plants offer wonderful winter attributes?"
These features are the "bones" of the garden.
The silhouettes of evergreens and the skeletons of woody plants contrast with the blinding white of a snowy January day. Between these "bones," seed heads, berries, and bark can provide the subtle variety that the color-starved eye in January pounces on, she said.
"After a snowfall, interesting mounds and shapes appear as snow covers Blue Fescue (Festuca cinerea) or Purple Dome aster (Aster novae-angliae 'Purple Dome') or any plant in the garden," she said.
To ensure better footing, stone walkways should be cleared of leaves. "But the rest can stay where they fall in a garden bed," Smith recommended. "The only items to cut back are those with known insect or disease problems, or plants that re-seed in areas where they are not invited such as Northern Sea Oats (Chasmanthium latifolium), Blackberry Lily (Bleamcanda chinensis), Black Eyed Susan (Rudbeckia hirt var. sulvantii 'Goldsturm), Tovara (Persicaria virginiana var. filliformis 'Painter's Palette), and Purple Cone-Flower (Echinaceas puruprea) to name a few.
"If you want these plants to mingle with their neighbors, leave them up to re-seed and provide food for the birds."
Ornamental grasses are beautiful in the winter. Miscanthus species such as "Gracillimus," "Morning Light," "Malepartus," "Blondo," and "Purpurascens" are just a few that stand guard over gardens in the winter.
"Sedum spectabile seed heads offer a beautiful burnt sienna to winter borders," said Smith. "Sometimes autumn winds knock over the heavy flower heads and force many gardeners to cut them back in the fall.
"Leave them if you can. You will enjoy the view in January."
While cutting everything back in the garden is a tool for control, Smith wonders if it is best for the plant.
"For certain plants like peonies, there is a benefit--removing old foliage reduces future disease problems," she said. "But for many perennials, advantages outweigh disadvantages. By not cutting back, fallen leaves can hold on better and insulate plants during bitter cold days and nights. This natural mulching prevents desiccation from strong, cold winter winds that otherwise would pull moisture from the ground and perennial roots.
"Snow is an excellent insulator but if it doesn't have something to accumulate over it, it keeps on blowing in the wind. Leaves and old plant debris will hold the snow. When the spring thaw arrives, all this moisture will be around your plants rather than melting down the drain."
But, she added, large, plate-sized sycamore or tough oak leaves can smother plant material. Some gardeners run them through a shredder or collect them in their lawn mower bags and return this mulch to the garden beds.
"The problems arise in the spring when these large leaves block air movement to the soil surface," she said. "If you leave these leaves on, make sure you are out in the early spring to stir them up. This allows air to reach the soil."
Spring clean-up will involve cutting back perennials and removing heavy accumulations of leaves and winter debris.
"You eventually have to do the work," Smith said. "But these tasks are often easier in the spring since plant remains are brittle and usually rake off easily."
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http://www.aces.uiuc.edu/news/stories/news4485.html
Contacts: Martha Smith, (309) 836-2363
Bob Sampson, (217) 244-0225, rsampson@uiuc.edu
