It is rare that we lose a hardy garden plant because of the severity of the season. Our climate allows us a wider range of planting options than most of the world. Even when we do get snow, it comes and goes quickly, revealing lush green lawns the moment the snow melts away, while much of the U.S. stays frozen for the better part of winter.
Our lawns go through a period of rest and recuperation in winter. If you use a slow-release fertilizer in autumn, it will be enough to sustain your grass lawns until spring growth begins. The ideal organic product will have an effect on the soil, which is the key to healthy plants of any kind. Avoid walking on the lawn as much as possible during winter months, especially if frozen or covered in frost. Rake up winter yard debris on mild, dry days.
This is an ideal time of year to rejuvenate deciduous shrubs. The simplest method for shrubs that produce a thicket of stems from ground level is to cut away all shoots to about 12 inches. On a spirea, you will be cutting off just below the spent flower heads. If a deciduous plant like mock orange (Philadelphus spp.) has been slow to flower, cut all stems back by half to encourage vigorous spring growth.
Prune summer flowering shrubs, especially those that have been slow to perform and have few blooms. Pruning now can coax them to make new shoots and flower buds. Cut away the oldest wood, as well as any weak, diseased, damaged or poorly situated branches for an open shape. For light pruning, you can wait until the end of winter. If a plant needs radical pruning, do it as early in winter as possible.
Lilac, hydrangea and other tall, multi-stemmed shrubs that have grown too dense will benefit by cutting back as much as one-third of the longest branches for two or three years in succession. I personally recommend a yearly habit of pruning out one-third of the oldest shoots. This way you keep the shrub to a manageable size from year to year. There will always be some older, flowering stems as well as new growth for plant vigor.
Check potted plants once again. Although we think that winter is a long, drawn-out affair, these few months go by more quickly than we think possible. A plant that is ignored for a month or more may be dying from extreme winter conditions. Monitor water needs and check for freezing conditions. Moisture in the soil of a potted container can expand and crack the bowl, not to mention the danger of freezing the roots of potted plants.
Stimulating growth
Annual deadheading is normally the only pruning you need to do on heaths, heathers and lavenders. This will keep the plants compact, vigorous and heavy flowering. Without pruning, these plants have a tendency to spread open and go bare in the center. Use garden shears to cut away the spent flower heads and about ¾ to 1¼ inch of the previous season’s growth. This will also stimulate dense new, spring growth.
Both the large shrub junipers and the creeping forms of coniferous ground cover can be pruned now. Spring growth will quickly cover the pruning cuts. Prune these plants rather than shearing them. Shearing a needled evergreen produces a dense outer layer of new growth that shades the inner wood and can result in die-back. Junipers are hardy plants that look best when pruned along the plants natural lines. Cut out branches that grow into walkways or other plants.
The easiest way to prune lanky evergreens is to take hold of the end of a branch that has grown too long. Follow it into the shrub and cut it off at a point where a healthy branch forks off and is growing in the direction you want the plant to grow. Think about how you prune roses above a bud to force the direction of growth. By removing only the leggiest branches in this manner, you should only have to prune junipers every few years.
I ran across a great idea on the Internet that I would like to try this year. If you use wooden or bamboo stakes in the garden, stand them in a bucket of wood preservative for a day. This treatment will prepare the stakes ahead of time and help them last longer once inserted into garden soil.
Gardeners are always coming up with new ideas, even in the midst of winter.
Robb Rosser is a WSU-certified Master Gardener. Reach him at Write2Robb@aol.com.
