By Lindsay Bond Totten
Scripps Howard News Service
Forget that old saw about perennials being flowers you plant just once, then stand back and enjoy. A perennial garden performs best when it's regularly tended.
Dividing, deadheading, weeding, mulching, fertilizing and staking are just some of the necessary chores, not to mention replacing specimens that have failed.
Most gardeners, especially those just starting out with perennials, assume that each variety is preprogrammed. Russian sage, for instance, will always grow to three feet tall. Peonies bloom for two weeks in May. Fall asters need staking.
That's just the way it is, they believe. For a shorter plant, one that blooms later, or a specimen that doesn't need staking, a gardener must choose something else.
Yet, within limits, many perennial plants can be manipulated. All it requires is a deft hand, a sharp pair of pruners or hedge shears and a little nerve.
Training can:
- Keep plants shorter and, in some cases, eliminate the need for stakes altogether (staking seems to be most gardeners' least favorite task);
- Coax more blooms from plants;
- Extend the season by forcing some varieties to bloom later than they normally would;
- Encourage many varieties to repeat bloom; and
- Adjust the heights and habits of many plants to make the garden look fuller and neater.
Training goes beyond deadheading. The removal of spent blossoms (and sometimes their stalks) is a weekly task that tidies the garden.
Peonies, for instance, are plants that demand deadheading. Cut the blossoms off as they fade to keep the petals from damaging the leaves and prevent seed pods from forming.
As I deadhead my peonies, I trim harder than I have to, taking off as much as a third of the foliage and shaping each plant.
Reducing their height after they bloom makes peonies more sturdy. I can remove their stakes--metal peony hoops, in this case--and reuse them somewhere else in the garden. The shorter, bushier plants will stand straight and look better for the rest of the season without support.
Training them in this way won't get peonies to re-bloom in the same season, but I haven't noticed any adverse effects on the following year's display.
Training is done by pinching, pruning or shearing plants during their active growth phase, but before they bloom. Most trainable are vigorous varieties, such as phlox, that have lots of stems and foliage and that normally bloom from midsummer through early autumn.
Pinching is the gentlest form of training: removing a couple of inches of growth from the tips of the stems when the plants are still young.
Phlox plants pinched when they're a foot tall will reach almost the same height as unpinched plants and bloom about the same time. But they'll be bushier, with more flowers.
Most summer- and fall-blooming perennials can be pinched with good results: phlox, Russian sage, daisies, boltonia, asters, balloon flower, lobelia, coneflower, turtlehead, beebalm, false sunflower and joepye weed.
Pruning and shearing are more heavy-handed and will have various effects on plants, depending on the timing and how much of the top growth is removed.
In general, the closer a plant is to blooming, the more pruning will delay its display. A phlox plant, trimmed by half in early June, for instance, may miss its normal bloom time by several weeks. The stems will be short and the flowers a little smaller than usual.
A fall-blooming aster is hardly slowed up by similar treatment. To reduce staking of asters and other autumn beauties, prune or shear once in June and again a month later. Bloom time will be delayed by no more than a week or two.
With experimentation, a gardener can orchestrate when and at what height certain perennials perform. Separate clumps of false sunflower or lobelia, for instance, can be pruned at intervals to extend the peak blooming season.
Achieve a layered effect by shearing some plants and leaving others at their regular height. This technique works especially well with beebalm, where the bushy growth of sheared clumps helps cover up the bare stems of the leggy plants behind them.
Don't hesitate to take control of your plants to get the most pleasure possible from your perennial border. The worst that's likely to happen is that a plant fails to bloom. Rarely does pruning kill a plant, and one that is weakened can generally be revived with fertilizer.
Photograph courtesy of arttoday.com
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