Spent my day stretching then prepping to work in the garden. Yes, work in the garden. The ground is still frozen but after careful inventory and a quick walkabout I found a couple of shrubs that needed some primping before the big burst of spring beauty and beautiful green skirts. Most of our shrubs and trees will benefit from an annual pruning. But you should refrain from pruning some of the flowering ones. Spring bloomers set flower buds the previous fall and pruning early would mean the loss of some of the flower buds. If you don't mind losing some blooms then an exception to this rule would be to prune while you can see the shape of your shrub or tree, but before the leaves appear.

Here is a list of some common trees/shrubs and vines:

Caragana, Deutzia, Forsythia, Flowering Almond, Lilac, Purpleleaf Sandcherry, Rhododendron pruned immediately after flowering.
In the case of Lilac and Rhododendron, if you don't need to prune for shape at the very least remove the spent flowers and prevent the plant from setting seed. This will make them more floriferous next year.

Birch/Maple should be trimmed while in full leaf or they will bleed.

Late Fall Early Spring, While Dormant
Summer flowering shrubs should be pruned in early spring before growth begins, then pruned again to remove spent flowers. These include Roses, Spireas, Potentilla, Butterfly Bush, Blue Mist Shrub and Hydrangea.

Deciduous trees except birch and maple
Pyramidal Cedars and Junipers light pruning to remove winter kill
Blue Mist Shrub (Caryopteris clandonensis)
Butterfly Bush (Buddleia Davidii)
Flowering Dogwood (Cornus florida)
Honeysuckle (Lonicera fragrantissiam)
Hydrangea, Peegee (Hydrangea paniculata ‘Grandiflora’)
Potentilla (Potentilla fruticosa)
Redbud (Cercis canadensis)
Spirea (except Bridal Wreath) (Spirea japonica))
Wisteria (Wistera species)

Most flowering vines – Clematis, Honeysuckle, Silverlace Vine, etc. – are extremely vigorous and should be pruned in early spring. Some Clematis, Nelly Moser and Duchess of Edinburgh are examples that flower on old wood, then flower again on new growth. If the vine is overgrown, you may have to forgo early blossom in some years.

Mid June
Pyramidal Cedars and Junipers another light pruning. Spreading evergreens sheared or thinned by removing individual branches. Make cut under overhanging branch and pruning will not be seen.

Spruce and Fir. New growth should be removed by about half in the third week of June. This provokes dormant buds to break, creates denser foliage and new buds will be set at the cut. Cut leader at this time. Do not cut below the lowest bud or the leader will die back.

Pines do not have buds along the stem, only on the tips. Enlarged buds are called "candles". Half of the candle growth should be removed each year, before the end of June.

Late Spring/Summer, After Bloom

Azalea (Rhododendron species)
Beautybush (Kolkwitzia amabilis)
Bridal Wreath Spirea (Spirea x vanhouttei)
Flowering Crabapple (Malus species and cultivars)
Forsythia (forsythia x intermedia)
Hawthorn (Crataegus species and cultivars)
Hydrangea, Bigleaf (Hydrangea macrophylla)
Lilac (Syringa vulgaris)
Magnolia (Magnolia species and cultivars)
Mockorange (Philadelphus coronarius)
Mountain Laurel (Kalmia latifolia)
Rhododendron (Rhododendron species)
Serviceberry (Amelanchier x grandiflora)
Slender Deutzia (deutzia gracilis)
Weigela (Weigela florida)

Bittersweet Vine and shrubs with attractive fruit or berries, some roses, cranberries, etc., offer no best time for pruning. If pruning is required, then do so after flowering, or make use of the decorative berries indoors by cutting the fruited branches – Holly berries at Christmas, for example. Spindly Mahonia with bare lower stems should be cut right down in spring.

High Temperature:
Actual: 5°C partly sunny Wind W20km/h P.O.P.0%
Average: 3°C
Record: 17°C in 1987

Low Temperature:
Actual: -9°C partly cloudy Wind WNW22km/h P.O.P.0%
Average: -6°C
Record: -21°C in 1984