Different pruning methods needed for different plants
Pruning is simply the removal of plant parts. Anyone can prune, but not everyone prunes properly. In order to prune properly, you need to understand how plants respond to pruning.
When a pruning cut is made on a stem or major limb, new growth will develop just a few inches below the cut. This is because of a hormone that is produced in the terminal bud (the bud at the end of a branch or twig). The hormone prevents buds directly below it from growing.
So when you routinely shear plants, a lot of dense, new growth will be produced near the outer portions of the plant. This will result in less light reaching the interior portions of the plant, foliage within the canopy becomes sparse and the plant appears stemmy or hollow. thinning plants
Thinning is generally a better method of pruning most shrubs. Thinning is cutting selected branches back to a lateral branch, a lateral bud or the main trunk. Thinning encourages new growth within the interior portions of the plant, reduces size and provides a fuller, more attractive plant.
Keep in mind the desired results when pruning. If you plant a row of shrubs that will serve as a hedge to screen a view, begin pruning them the same year that you plant. Many times people wait several years before pruning a newly planted hedge.
This can result in little growth at the base of the plants, which means a privacy hedge that can be seen through. Because of the fact that new growth on plants only occurs a few inches below the cut, you should begin pruning early to encourage a compact growth habit.
Pruning time varies among plants. Ornamental plants that are not grown for their showy flowers, such as holly, boxwood, privet and red-tip photina can be pruned during the late winter, spring or summer months. Avoid pruning during the fall or early winter because the new growth produced as a result of pruning will be subject to cold injury.
As a general rule, plants that flower before May, like azaleas, Bradford pear, forsythia, pyracantha, spirea and climbing roses should be pruned shortly after they bloom. It is best to avoid pruning plants in this category later than July because they set flower buds in the fall.
Plants that bloom after May are considered summer-flowering and can be pruned just prior to spring growth in late February or early March. A few plants that fall into this category are crape myrtle, gardenia, bush roses, abelia and hydrangea. An exception to this rule is the Oakleaf hydrangea, summer-flowering shrub that forms flower buds the previous season.
Some homeowners make the mistake of planting large-growing shrubs along the foundation of the home which eventually become overgrown. When this occurs, you may need to prune severely (called renewal pruning) to bring the plants within bounds. Renewal pruning means cutting the plants back 6 to 12 inches above ground level. In this instance, timing is more important then technique . The best time to prune severely is when spring growth begins – mid-February to mid-March. Renewal pruning should result in abundant new growth by mid-summer. Most broadleaf shrubs (such as azaleas, camellias, privet, abelia, nandina, cleyera and crape myrtle) respond well to renewal pruning. Boxwoods, however, recover slowly and may even die when severely pruned . Also avoid severely pruning junipers, pines, cypress, cedar, arborvitae and other narrow-leaf evergreens because it may cause them to die.