The plants that will need pruning this winter through early March are woody ornamentals and summer flowering trees and shrubs. Examples of summer flowering plants would be crape myrtle, abelia and althea.
Prune spring flowering plants such as azaleas, forsythia and dogwood soon after they bloom.
Even though florist hydrangea and gardenias are considered summer flowering, wait until they finish their peak bloom time before you trim them.
Naturally, if you see dead plant material, you can prune that off any time.
When it comes to pruning, many gardeners fear they will hurt the plant.
Pruning removes diseased wood and can rejuvenate overgrown shrubs.
Proper tools are a key to successful pruning. For the most part, try to steer away from gas-powered or electric sheers. Hand-operated sheers work best as long as you keep them sharp.
With hand pruners, you really get what you pay for, so buy the best quality you can afford. The scissor pruners are the most useful. The anvil types are not as good. They tend to crush limbs rather than cut them.
Use lopping shears to prune small trees or shrubs with diameters up to 1.5 inches. For plants with branches more than 2 inches thick, use a pruning saw.
There are two pruning methods: heading and thinning. Heading is when you shear across the plant nonselectively. This method is normally used on boxwoods or dwarf yaupon holly to give them that formal look. Use heading sparingly, especially on larger, leaved shrubs, because it causes excess canopy growth.
Thinning is a more useful cut and gives plants a more natural appearance. Use thinning cuts to prune out sections of the plant to allow more light and air inside. The increased air reduces diseases and insects such as spider mites. And wasps are less likely to build nests in your shrubs.
How you prune determines the shape of your plant. If you leave buds on the outside it causes plants to grow outward and spread. If you leave buds on the inside it causes the plant to fill out from within. When pruning, try to leave the bottom of the plant wider than the top so that it forms a pyramid shape. If you don’t, you will cause a canopy effect, and not much light will get to the bottom and your plant will slowly lose foliage down there. This is probably the biggest pruning mistake I see in the landscape.
Make your cuts at a slant and a fraction above the bud. The slant will allow water to roll off the newly cut surface. Don’t use pruning paints. They are unnecessary and may actually slow the healing of the cuts.