The Homeowners Column

The Homeowners Column

Winter – No Time to Be Dormant In the Garden

Photo of Sandra Mason

Sandra Mason
Extension Educator, Horticulture
slmason@illinois.edu

We usually have a long window of opportunity to do many of our late winter chores. We can pick the right day to suit our comfort level generally now through early March. This year may be an exception, with our early warm weather many plant buds are ready to explode. Don't delay on any dormant season activities. So bundle up and head outside for these items on your "to do" list:

Ornamental grasses swaying in the breeze add interest to the winter garden. In order for them to look good this growing season, however, the dead leaves and stalks should be cut back to about 4 inches before growth resumes. Tie the dead leaves together first. Some of the stalks can be particularly tough to cut. Electric hedge trimmers work well. Cool season grasses such as Feather Red Grass (Calamagrostis acutiflora) green up quickly in spring. The popular Miscanthus cultivars are warm season grasses so you have more time to tackle them.

Prune trees and summer flowering shrubs while still dormant. Many shrubs can be reduced in size by using renewal or heading back methods. Sterilize tools in between each cut with 10% bleach when pruning diseased plants. Summer flowering shrubs such as pink spirea and redtwig dogwood bloom on new wood after mid June. Renewal pruning method is the removal of the oldest stems leaving the younger stems to develop. Spring blooming shrubs such as lilac and forsythia should be pruned after flowering.

When pruning trees, avoid flush cuts or stubs. Be sure to maintain the branch bark ridge which is a roughened bark area where the branch attaches.

Apply dormant oil spray to euonymus to control the insect euonymus scale. Dormant oil sprays will also give partial control of pine needle scale. Temperatures should be above freezing for 24 hours after spraying.

Some scale species such as oystershell scale are not controlled by dormant oil sprays. Get accurate identification of insect to determine control program.

Remember when pruning grape vines the grapes are produced from the buds of one year old canes which are about 1/4 to 1/3 inches in diameter and are reddish brown. When properly pruned, 80 to 90 % of the grape wood is removed every year. Now you know why people can make so many grapevine wreathes.

Grape vines with a main trunk and four canes are often trained to a two-wire trellis. Before pruning, select four strong lateral one-year-old canes (arms) that are close to the trellis and mark with a ribbon or colored tape. The largest and heaviest canes are not good fruit producers.

Tie the four arms to the trellis. Choose four more lateral canes to become the arms for next year. Remove everything else. Prune off the ends of this year's arms so that 10 to 15 buds remain on each of the arms and only two buds are left on the renewal spurs (next year's arms).

Prune red raspberries. Remove all short and weak canes. The large remaining canes are thinned to 4 to 8 inches apart. The canes are cut back to 5-6 feet tall or if no support is provided 3 to 4 feet tall. Last year's productive canes should be removed anytime after harvest or remove them now. Canes are productive only one year and the new growth will produce the next year's harvest. The exception is everbearing raspberries such as 'Heritage' which produce a second crop in the spring on the canes that produced last fall.

A handy publication, Growing Small Fruits in the Home Garden, is available for $5 plus shipping and handling from University of Illinois Extension or check with your local county Extension office. Or download our Landscape Maintenance Calendar .

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