How to Cut Back Perennials
Cutting back perennials some time after they die back after a hard frost is important to keep your perennials looking good.
By Veronica Lorson Fowler
The Iowa Gardener
Sure, you could never cut back your perennials and they'd come back, but frankly, your garden would look like hell. All that dead stuff would just stick around all growing season long.
Also, one theory is that leaving too much perennial foliage (especially if it's had problems) over the winter allows diseases and pests to overwinter.
So I encourage you to cut back your perennials!
• Some gardeners like to do this in fall, once a hard frost has killed the tops of the perennials. Others like to wait until spring. It's really a matter of personal preference--and when you have the time.
• There's no need to cut back everything in fall. Me, I cut back the perennials that don't look good through the winter, such as peonies, daylilies, hostas, and irises. But I leave perennials whose tops dry nicely. Those I leave standing to enjoy looking at in the winter. These include ornamental grasses, sedums, and purple coneflower (the goldfinches love them!)
• To cut back a perennial, simply cut it off an inch or two above ground level with a pair of hand-held garden shears.
• To save time and blisters, I personally prefer to use an electric hedge trimmer to cut back larger stands of perennials. It costs just $30 but saves much time and many blisters. I use it in the spring, too, when cutting back those tough ornamental grasses.