January 7th, 2006
So, it’s the middle of winter and temperatures have suddenly reached a balmy level. As a gardener, you’re itching to get out and piddle around in the yard. But what’s to do this time of year?
Turn to your trees and shrubs – they could probably use some attention while they rest comfortably in winter dormancy. Here are some winter pruning pointers:
Non-flowering hardwood trees and shrubs should be pruned at this time of year to improve the plant’s structure. Making cuts in the dormant season also reduces the chance of transmitting disease, discourages excessive sap flow and avoids the problem of possible pest infestation. Conifers can be trimmed any time, but are best pruned during the dormant season, as sap and resin flow are minimized from the cut branches.
Flowering trees and shrubs, with a few exceptions, should also be pruned during the dormant season for the same reasons stated above. However, do NOT yet prune trees and shrubs that flower in early spring – you’ll be cutting off the buds that will open in a few months. Spring-flowering trees and shrubs should instead be pruned immediately after flowering. A good rule of thumb is that you should prune in the season opposite of flowering, i.e. flower in spring = prune in fall, and flower in summer = prune in winter.
Ornamental grasses that die during the winter should be given a ‘flat-top haircut’ about 3″-4″ above ground at the end of winter, before new growth starts to emerge. Evergreen grasses should be left alone.
Of course, dead branches and canes can be removed any time of the year, especially those obviously suffering from insect and/or disease damage. If you suspect disease, be sure to disinfect your pruning tools with a germ-killing spray like Lysol before and after cutting plants. Do not put diseased or insect-infested cuttings in your compost pile.