I love pruning. It is one of my most favourite horticultural services that I offer to my clients. But to many people, it is a daunting task. I have had a number of clients who were afraid to touch their shrubs and trees. In many instances, people either just don't prune at all, or do it very badly, both to the detriment of the plant. Of course, I would opt for people not touching trees at all if they really are not sure of what they're doing because damaging cuts cannot be reversed. I would much rather come in to prune an overgrown shrub that still has branches intact to choose from than try to reshape one that has been misshapen by bad decisions.
Why prune? In nature, pruning is second-handedly performed by nibbling animals or by climate activity such as wind, ice, and heavy snow, but neither of these are actions performed intentionally to improve the aesthetics or health of the tree. This winter, all six of my newly planted New Jersey Tea shrubs have been eaten to the ground by rabbits. Well, the purpose of native plants is to support wildlife after all. I fully expect the shrubs to regrow and with any luck the rodent pruning will actually help plant vigour and encourage more shoots for a fuller shrub. This is also one reason why we intentionally prune our landscape specimens. Rabbits very often 'snip' the stems off much like secateurs, so very often it's a nice clean cut and trees will respond positively to this, though the cut is not always in a desired position. Animals that tear, crush, uproot and de-bark, including people, expose trees and shrubs to risks of disease and pests because the wound simply does not seal properly. This creates misshapen limbs and trunks, it promotes erratic growing patterns and extends the length of time during which opportunistic diseases and vectors can enter the tree's circulatory system. While functional pruning doesn't happen naturally in the environment, it is a useful and recommended practice for specimens in our gardens to promote and extend beauty and can save us money in the long run.
Every visit I make to a client's garden, I quickly assess the shrubs and the trees most prominently planted. In the spring, I prune out dead, diseased, and damaged branches. This can be done at any time throughout the season however the more you can identify early in the season, the healthier the tree will grow. I also assess for crossing branches which can potentially cause branch rubbing and entry portals for disease. Removing these also opens up the centre of the shrub, improves structure, and allows for air movement preventing fungal invasions.
When a shrub is overgrown, rather than pulling it and replacing it, it can often be refreshed with rejuvenation pruning. This may be as little as cutting out old, thick stems which then promotes new fresh growth (i.e. Spirea spp. or Physocarpus spp.) to as much as coppicing an old shrub to trigger new, and often more vibrant, stem growth (i.e. Cornus spp. or Hibiscus syriacus). I have also pollarded trees which keeps them at a manageable height, yet allows for new branch formation (i.e. Cornus spp. standards or Salix spp.) I carefully review each situation, species, surroundings, and client desires, and provide information from which to derive a pruning plan, with my suggestions first and foremost based on plant health. I also would not normally ever recommend coppicing or pollarding a tree or shrub as these practices usually infer wrong plant, wrong place. As a consultant, I prefer to meet with my clients before purchasing trees or shrubs for their landscapes to carefully advise them of what will work best, what will avoid problems in the future, and ultimately what will save them money in the long run.
Pruning either promotes new growth and second flushes of flowers (i.e. Spirea spp.) or maintains shape and size (i.e. Yew spp.) depending on the plant's habit and time of season. Sharp cuts allow the tree's internal defense mechanisms to seal off evenly and quickly. Jagged wounds are more complex, slower to heal and create added opportunity for disease invasions. Trees must exert great energy to tend to damage and this causes stress which affects all functions of growth, tolerance and longevity.
It is important to have sharp tools to deliver clean cuts, to sterilize them between cuts (and especially between species and specimens) to avoid introducing disease, and to remove all diseased material from the area. There are a series of proper cuts to make when removing tree limbs, no matter the size, to avoid bark peeling and creating a worse wound less able to repair itself. Pruning varies by species, by flowering time, by growth habit, and a horticulturist is trained to do the job properly.
When pruning is something that strikes fear in you, or if you're really not sure of the proper way to approach it, as a horticulturist I am happy to spend time with my clients to develop a pruning schedule and/or to teach them the right way to go about it. Once you understand how a tree reacts and grows, it's not that scary. A professional pruning will make your tree healthy and happy. On consultation for larger tree specimens I will always recommend an arborist to do the job.
This photograph is one I took a number of years ago - a lone old apple. I loved this tree. It no longer stands in the field.