Tuesday, February 21, 2012

When To Prune Your Trees and Shrubs

Late winter and early spring is the best time to prune many of your trees and shrubs. With pruning season nearly upon us here is a pruning schedule for many of the commonly grown trees and shrubs.
· Spring flowering trees and shrubs: Should be pruned shortly after the flowers begin to fade. Removing spent blooms (dead heading) helps to redirect the plants energy into making bigger and plumper blooms for next season, rather than using that energy for seed production. Examples of spring flowering shrubs include: forsythia, flowering quince, lilac, Rhododendron, azalea, beauty bush, mock orange, red bud, flowering dogwood, firethorn, Japanese snowball, magnolia, viburnum, honey suckle, and others.
· Summer flowering trees and shrubs: Prune these in late winter or early spring, before growth appears. Examples include: Rose of Sharon, Snowberry, St. Johnswort, ‘Pee Gee’ Hydrangea, smooth Hydrangeas such as ‘Annabelle’, Buddleia davidii and others.
· Roses: When to prune your roses depends largely on whether it blooms on old or new wood and whether it blooms just once in the season or repeatedly. Generally all roses should be pruned to open the center of the plant to both light and air circulation; Make your cuts at a 45-degree angle, about 1/4 inch above an out facing bud; Also remove any broken, dead, dying or diseased wood as well as any crossing or badly placed branches; Remove sucker growth below the graft; Remove any weak or twiggy branches thinner than a pencil. This type of pruning should be done in late winter or early spring. When your forsythia is blooming you will know it is time to prune your roses.
hybrid tea roses: The ones with the large single blooms that gardeners have grown to both curse and love should be pruned hard in late winter or early spring. Dead head these roses throughout the growing season to encourage additional blooms. Stop pruning about 6 weeks before the first expected hard freeze to give the roses a chance to harden off before winter.
Climbers: For once blooming climbers, prune when the flowers begin to fade. For repeat blooming climbers (that bloom on new wood or both new and old wood) prune in late winter or early spring. (At the same time as you do your general rose maintenance pruning.)
shrub roses: (for once blooming prune when flowers begin to fade for repeat bloomers prune in late winter or early spring and dead head and lightly prune throughout the growing season.)Every rose requires pruning to keep it healthy and to keep it flowering well.
· Deciduous trees: As with roses prune out all dead, diseased and damage branches in late winter or early spring.
Non-Bleeders: Late winter early spring is the best time to prune the majority of deciduous trees. At this time there are fewer insects and diseases to invade the open wounds. Another benefit of early spring pruning is that it stimulates new growth and pruning cuts are quick to heal. It is also much easier to see the shape and inspect the health of the limbs without all of the foliage getting in the way. Trees that you should prune in late winter or early spring include: Aspen, Burning bush, Elder, Ginkgo, Harry Lauder's Walking Stick, Hazelnut, Linden, Mayday, Mountain Ash, Poplar, Willows, Holly, Hawthorn, Honey locust and more.
Bleeders: A group of trees generally not recommended for early spring pruning are known as "bleeders". These are better pruned in summer when they are in full leaf. During late winter and early spring the sap is rising, and will "bleed" from open wounds. This does not harm to the tree but can make for an unsightly and sticky mess. Maple is the most common and famous in this group of trees, which also includes birch, beech, oaks, Walnuts, lindens, and elms.
· Fruit trees:Renovation and maintenance pruning are best done in late winter, while the trees are still dormant. Later on in the season, around mid-June, it is often necessary to remove excess fruit by hand when it is still very small. Fruit thinning reduces limb breakage; increases fruit size, improves colour and quality of remaining fruit, and stimulates flower initiation for next year's crop. Most apple, pear, and peach cultivars should be thinned until the fruit are no closer than 20 cm. Plum and apricot fruits should be far enough apart that they do not touch one another when mature.
· Evergreen trees and shrubs:(prune when actively growing)
Pyramidal Cedars and Junipers may be lightly pruned in early spring to remove any winter-killed tips. By mid-June, it should be apparent that shearing is needed again as the warmer weather produces a rush of growth.
Spruce and Fir produce buds along the branch. New growth should be removed by about half in about the third week of June. This provokes dormant buds to break, creates denser foliage and new buds will be set at the cut.
Pines do not have buds along the stem, new growth occurs once a year from terminal buds only (tips). As these buds (called candles) enlarge in the spring, 1/2 to 2/3 of this growth may be removed each year, before the end of June.
· Vines:
 a.Clematis: are pruned in 3 different ways depending upon its season of bloom and wehether it blooms on old wood or new.

Group 1: This group contains some of the most vigorous clematis. They flower on old wood. Although this group does not require pruning (other than to remove deadwood), you may wish to prune in order to control its size. Any pruning should be completed as soon as flowering has finished.

Group 2: This group contains the early and mid-season large flowered hybrids which usually begin flowering before the end of June. They also flower on old wood. The only pruning usually required in this group is to prune out dead wood in late winter/early spring. To do this prune back to (just above) a plump pair of buds.

Group 3: This group contains late flowering species and hybrids. This group flowers on new wood. Prune this group back hard (approximately 30cm (12") from ground level, cutting just above an old leaf joint) in late winter/early spring.
b. Wisteria: Prune the entire plant back after flowering is finished, thinning it out well and leaving just one or two buds or nodes per branch. In mid-summer give the vine a good hard pruning to maintain desired size and shape. Give it a final pruning in mid-September (or when growth has slowed, due to the onset of cooler temperatures).This time, leave four or five nodes or buds per branch; these will form next year's flowers and branches.
C. Virginia creeper, ivies, hops and grapes (are all pruned in late winter or early spring). Perennial sweet peas are best pruned in late autumn.
· Grasses: Although grasses may be pruned in late autumn many gardeners enjoy the look of grasses in their winter landscape. Grasses left to stand over winter are best pruned in late winter or early spring before new growth begins.

1 comment:

  1. Great tips. Sharing stuff like this is always welcome especially to gardeners and landscaping enthusiasts.