How to prune evergreen trees and shrubs. Growth habits of pines, spruces and other evergreen shrubs are discussed including identifying 'candles' on pine trees.
Pruning Evergreen Shrubs and Trees
Evergreen shrubs and trees need more careful pruning than deciduous shrubs, however as a general rule they rarely need more than a little, if any, pruning on an annual basis. Again, like Pruning Deciduous Shrubs, there are two types of evergreen shrubs and trees to consider. The first type can be pruned almost any time of the year. The new leaves grow on new wood and they can regenerate this new wood from old wood. These plants are the ones that are used in hedges and ornamental garden designs, including topiary. Boxwood and holly are two such 'clippable' evergreens. Do not prune these shrubs late in the year as that will encourage new tender growth that can be damaged in northern winters.
Pines and spruces are slightly different in that they do not regenerate easily from old wood. Many pines produce 'candles' during the year that are the new growth for the following year. The candles can be recognized by looking at the tips of the pines. Look for small radiating stubs forming during the year. These are the pieces that grow the following year and produce more candles for the subsequent year. This new growth should be can be trimmed back early in the season so that the new candles can form. Do not completely remove the candles or the new growth. Do not prune these trees beyond that point either.
Other evergreens such as spruces work in a different way by not producing candles, so they can be trimmed at any time in the growing season. Again though, you should take care not to cut into old wood. Timing the pruning with these shrubs can vary, but if you do it too early in the growth cycle, you will find that you have stimulated more new growth and need to re-trim later in the season. Obviously if you need a neatly trimmed hedge then you will be trimming several times a year anyway, but for those of us who prefer to trim just once in the year, timing is the key to neatness. Your specific climate and shrub will dictate the optimal time to prune them.
As with any shrub it is important to look at the overall shape of the shrub. Many will adopt a beautiful natural shape that needs little or no pruning. Look at the label that comes with the evergreen to determine the final height and growth rate. Slow growing items require less pruning, and will take many years to attain its final height. Consider what height you want the item to reach. An evergreen that has a normal growth rate and attains a mature height of ten feet should not be used in a hedge, or under a window, where you want to keep it to four feet. You will always be fighting with the shrub to keep it at an abnormal size.
Find out how to Prune Deciduous Shrubs
Learn more about Landscape Trees
©Text and photograph by Kate Copsey, May, 2006. Reproduction without permission prohibited.
