Pruning Dormant Plants:
How to Prune Your Garden Plants in the Winter
By Dr. Leonard Perry, Extension Professor,
University of Vermont
Eager to get back in the garden? If you have trees and shrubs, those "warmer"
days of winter are a good time to prune many of them while they are still
The rule of thumb is to prune those woody landscape plants that bloom on
current season's wood while dormant. Those that bloom on the previous
season's wood, prune after they bloom in late spring on early summer.
Examples of those that you should prune after bloom are lilacs, forsythia,
rhododendrons, and early viburnums. Prune these right after they bloom, as
they will then start forming flower buds for the following year.
This is one answer to a question I often get, "Why didn't my shrubs bloom this
year?" Pruning these during summer or fall will cut off next year's flowers. I
often see this with forsythia, which grow rampant and gardeners "shape" during
the growing season. Of course broken branches can be pruned off now in winter.
So all the rest you can prune now while still dormant and resting for winter.
Some of the common shrubs you prune while dormant include glossy abelia,
barberries, blue mist (Caryopteris), summersweet, smokebush, spirea,
cotoneasters, and late viburnums (such as blackhaw and American cranberry
Depending on how high you want these to grow, you can prune them back to as
much as above the first pair of buds above the soil.
A drastic version of cutting back shrubs in winter is known as "renewal"
pruning. This involves cutting a shrub back to about six inches above the
ground, and only is suitable for some plants. This is a good practice for these
shrubs if they didn't bloom as in the past, or look overgrown with weak and
Renewal pruning invigorates these shrubs, as drastic as it sounds and looks.
Candidates for this include glossy abelia, barberry, blue mist, forsythia,
honeysuckle, ninebark, shrubby cinquefoil (Potentilla), hibiscus, lilac, spirea,
If you can't bear to cut these shrubs totally back, or don't want the sight of an
empty spot in the garden or landscape while they regrow, cut back in stages
over a three year period.
With this plan, only cut back to the ground about one third of the oldest stems
each year. Some rampant growers, such as forsythia and ninebark, you may
want to continue renewal pruning each year. Some gardeners practice this
regularly even with shrubs such as lilacs, in order to keep them lower.
Cutting to the Ground or "Coppicing"
A variation of renewal pruning is known as "coppicing". This cutting to the
ground during winter stimulates vigorous new growth each year. In the case of
shrubby dogwoods and some shrub willows, it can stimulate more brilliant stem
The sacrifice, though, is cutting off flowers and fruits. If you want these, then
only coppice every other year. If butterfly bush survives in your area, this too
can be coppiced. A favorite large tree to coppice is the Princess tree
(Paulownia), creating tall bushy plants with large leaves each year.
A type of winter pruning of trees, seen more in Europe than America, is called
"pollarding". This involves cutting trees back to the same point each year to
control growth and shape. The result is a knobby fist where shoots grow from
each year, a rather odd appearance if you are not used to this. Purple
smokebush is one small tree you might try this with. I have seen it quite
commonly on street
Don't Prune "Bleeders" in the Winter, Like Maple
A group of trees generally not pruned in winter are known as "bleeders". These
should be pruned in summer after they leaf out if possible. During late winter
and early spring the sap is rising, and will "bleed" from open wounds. This
does little harm to the tree except perhaps providing a site for disease infection,
even though we equate this to our own bleeding.
Maple is the most common and famous in this group of trees, which also
includes birch, beech, oaks, lindens, and elms.
Trees that you should prune in winter or late winter include apples, flowering
crab apples, mountain ash, hawthorn, and honey locust. These may get bacterial
and other diseases (stem canker in the case of the latter) if pruned in summer.
The Advantages of Winter Pruning
Pruning in late winter is good in the sense that diseases are not active then to
invade the open wounds. When the plants resume growth in the spring shortly
after pruning, the wounds will heal rapidly.
Pruning in winter, especially if severe pruning, will stimulate the plant to
replace leaves and shoots first, perhaps at the expense of flowering, so is a fact to
keep in mind if flowering is important.
Keep in mind too that a tree or shrub, even after pruning, will grow back to its
natural shape. If you want a certain shape in the landscape, it is easier and saves
much pruning to choose a plant with that shape naturally.
There are many online resources and books on pruning, including when and diagrams
showing how, including The Homeowner's Complete Tree and Shrub Handbook by