Lavender is best left intact over the winter. Prune the plants in spring. (Stock Xchange)
At this time of the year, those of us who grow perennial plants have to make some big decisions — to cut or not to cut when preparing the garden for winter.
There are those who like the tidy look and cut their greens to the ground. Others prefer to let Mother Nature do her thing and wait until spring to clean up the garden.
Perennial maven Tracy DiSabato-Aust, author of the best-selling “The Well-Tended Perennial Garden” (Timber Press), prunes with her eyes as well as the needs of the the flora and fauna. She and I agree, seed pods, dried flowers and stems become magical when frosted by a hoar frost or coated with a dusting of snow, so they are left standing
The seed heads of Echinacea, Heliopsis and Rudbeckia are relished by winter birds such as finches, chickadees, nuthatches and cardinals.
Waiting until Jack Frost arrives with a killing frost will tell you which plants turn to mush and should go and which ones remain green. In the shade garden, Pulmonaria, Heuchera and Heucherella, and some ferns continue to provide color. Hellebores stand up to frigid weather, preparing to flower in late winter or early spring.
Perennial grasses provide height, texture and movement in the winter garden, but should be cut back in late winter or early spring before new growth emerges.
Woody, shrub-like plants, such as lavender, sage, thyme and Santolina, are best left intact over the winter. The time to prune them is when the first bit of green emerges in spring.
Hardy chrysanthemums are also left standing over the winter, as are hardy Salvias. Shearing off the spent blooms will tidy them up. Tests show the stiff stems protect the crowns and help to insulate them.
Tall Sedums, including ‘Matrona’ and ‘Autumn Joy,’ provide outstanding architectural interest right through to spring.
If re-seeding of Phlox paniculata, Aster novi-belgii and others occurs to the point of weediness, cut the offenders to the ground this month.
Plants prone to diseases, such as peonies and monarda, should be cut to the ground in fall so trouble doesn’t overwinter in the soil. The foliage of any plants that suffered from mildew or any other disease should be disposed of in the trash.
“The Well-Tended Perennial Garden” includes an encyclopedia that details the pruning techniques for dozens of plants. If you enjoy growing perennials and want to become skilled in their care, this book is a must-have.
Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question, go to Yardener.com and click on Ask Nancy. You can also read her previous columns at detroitnews.com/homestyle.