The Plant Professionals: Pruning- how, when and why?

 

For some gardeners a sharp pair of pruners or secateurs is a powerful tool for shaping, thinning and removing any broken, diseased or crossed branches in shrubs. For a novice gardener, there is often hesitation and anxiety. How do you decide what needs to be removed? 

 

First , assess whether your goals can be accomplished by pruning at all. If you have a very large and overgrown shrub that is blocking your windows or scraping the car along the driveway, often the solution will be removal and replacement, rather than simple pruning. Pruning lightly stimulates new growth, can cause unnatural growth called “witches broom”,  and pruning also can result in bare and even sharp branch ends if you are pruning deeply into a shrub with no interior foliage. Take  photos  from a couple of angles and share with a professional or your county extension agent to be sure of what species the shrub or tree is, whether it can tolerate a hard pruning ,and whether that pruning will leave you with a useful and attractive specimen after a year or two of recovery. 

 

If your shrubs are simply growing out of the original tidy shape, or if you would like them to remain a few inches shorter than current height, that can usually be accomplished with periodic skilled pruning. 

 

Many decorative deciduous shrubs are planted for their beautiful flowers. Depending on the species and variety, pruning should be done either in the winter when no foliage is present or soon after blooming in spring or summer, so as not to cut off the buds that will become the next seasons flowers. Winter dormancy is often the recommended time for non-flowering shrubs. In winter dormancy you are also less likely to transfer insects and diseases between plants, but clean your pruning tools with alcohol between plants and at the end of the pruning project. 

 

These days, many shrubs in garden centers and nurseries are bred to remain compact and require minimal pruning. Perfect for a low maintenance garden, but not helpful if you are trying to plant a screening hedge between neighbors. Always read the tag and then take that quick extra step of pulling out your smart phone and researching to be sure the shrubs you are considering are hardy in our zone 5 and will be a size and shape you are looking for. It doesn’t happen often but sometimes the large “big box” retailers get stock in that isn’t hardy this far north. 

 

If you have boxwoods, note that they do best when hand pruned, as the heat from the power hedge clippers seems to damage the edges and leave dead leaves visible. Most of the conifers such as pine and spruce should not be pruned, as they have one central leader that cannot be removed without forever altering the shape . Among the junipers and the yews, different varieties have different need and tolerance for pruning, but most evergreens will never regain their form if pruned back hard. . Get some advice from a professional or a more experienced friend before taking pruners, loppers or a saw to any evergreen. 

 

If you will be pruning for the first time, but will be pruning again over time, invest in a pair of well-made bypass pruners that fit your hand comfortably. There is less crushing of plant tissue, and used properly you are only damaging the part you are pruning off. Anvil pruners crush tissue on both sides of the cut, so the cut is not as clean and there is more likelihood of a wound that can get infected. 

 

Kathy Valentine enjoys gardening and her family at her Watertown Township home. Her Michigan State University Horticulture degree was a beginning for a life of learning about and working with plants. Kathy is senior partner at The Plant Professionals located at 16886 Turner St, Lansing, MI 48906.  

 

It is an interior and exterior  landscape design , installation and service firm  also offering green walls and plants and flowers for events. She may be reached at 

517-327-1059.