Your Guide to Pruning
By Dave Van Raay
Often times, Sue and I will take the long way home, detouring through Chatham’s beautifully landscaped suburbs. Large, mature specimens in an array of vibrant tones are what make our town’s curb-appeal stand out amongst thousands of surrounding communities. One of the reasons why Chatham is a multi-time winner of the Communities in Bloom Award! However, often times I see trees and shrubs that have been pruned improperly or simply not pruned at all and over time they begin to lack huge appeal potential. Pruning is an ongoing task in most gardens and needs to be considered during every season. So let’s talk about what you could be doing now (late spring) to make your trees and shrubs healthier and more stunning this year and 5 to 10 down the road!
If you have evergreens, such as Mugho Pine, Dwarf White Pine or Japanese Pine, they will be growing ‘candles’ in late May early June. ‘Candles’ are those fresh, new growth tips at the ends of every branch, often more vibrant than the previous years’ growth. If you desire to keep these evergreens compact and shapely, nip those candles in half or even slightly more and this will force more ‘growth within’. By ‘growth within’ we mean the growth on the inside of the plant which creates a much more dense, compact, and lush plant.
During the early stages of ‘candle’ growth, you can actually trim with your thumb and forefinger as the growth is soft, like Asparagus. As they mature, you will need to use pruners. A rust-free and sharp set of secateurs is always better, creating clean, crisp, and healthy cuts.
Cedar, Spruce, Boxwood, and Holly flush out new growth in late spring as well. These can also be shaped now, but you’ll definitely need a good sharp pair of long shears to make shaping easy and clean. By trimming the outside of the shrub, again, you’ll be encouraging new ‘growth within’, which always makes a more dense and compact shrub.
Pine Tree Growth Spurts | Image by: Alan Levine
Junipers and Yews tend to produce most of their growths only on the ends. So, if we religiously cut back the ends each season, we will reduce the shrubs’ overall sizes, while forcing new ‘growth within’, making them fuller for years to come. If your Juniper or Yew is already over grown, it’s not too late! Prune back some of the long, stray branches as far as needed, but be sure to study the plant first and decide which branches and how deep you can prune back out without leaving any gaping holes. This is called ‘selective pruning’, as opposed to shearing.
Many flowering shrubs are currently full of buds just about to bloom or are already the focal point of your garden, full of luscious vibrant blooms. However, many flowering shrubs have already finished blooming and their spent flowers can create an eye sore. My rule of thumb is ALWAYS prune after flowering shrubs are done blooming!
Flowering shrubs, such as Rhododendron, Azalea, Lilac and Forsythia, that have already bloomed should be trimmed now. Trim all the spent seed heads off. Do not be afraid to cut back a bit of the branch, as well, to help shape or reduce size (perhaps 4” – 6”).
Always trim to the ‘fork in the road’, meaning just beyond a set of lateral branches, without losing that fork. Within a few weeks you will notice new buds sprouting and, instead of having that one long, straight branch, you will have forced two new sprouts right at the point where you made that cut. Again, you’ll be creating a healthier, more dense, and sturdy shrub.
Many up-and-coming flowering shrubs, such as Spirea, Weigela, Roses, and some Viburnum, should not be trimmed yet, unless the variety has already bloomed. Leave the trimming until it has finished. Once these profusive bloomers have finished, sharpen your shears and give them a good shaping. This is a nice, clean, and quick way to get rid of all the spent flowers and force new growth for flower buds to re-develop on. Spirea, Weigela Potentilla, and other reblooming shrubs will flower several times through the summer and usually go into flowering lulls in between. This is your cue. Trim lightly, but regularly, and this will keep them compact and neat.
Hydrangeas, stunning summer bloomers, are a bit of a topic of their own. There are several different types and they should each be treated as their own, but generally should be trimmed in either early spring or late fall.
To simplify, the large lush leafed ‘Macrophylla’ varieties, such as Endless Summer, All Summer Beauty, and the City Line Series, among others, tend to grow back from a low mound of branches every year. Trim only as far back as the winter ‘dieback’ occurs on the plant or you could adversely affect the flowering ability for the upcoming season. Trimming back less is better. We’re currently past the new growth stage, so any stem not producing leaves yet can now be removed to tidy it up. Feel free to deadhead any spent flowers throughout its blooming season.
‘Paniculata’ Hydrangeas, such as Limelight, PG and Little Lamb, or ‘Arborescens’ Hydrangeas, such as Annabelle, Invincibelle, and Incrediball, can all be pruned back quite hard in late fall or early spring and this should not affect their flowering. Once again, it’s currently a little late to hard trim them but if you feel it’s necessary, you can still prune the branches of most of these varieties back by 25 – 50% and they will still flower nicely, just a little later in the summer.
Shade & Ornamental Trees
Now is actually a good time to prune and shape your shade and ornamental trees. Go ahead and trim back any noticeably dead wood and long, lanky branches to encourage that ‘growth within’. Beware of my rule of thumb mentioned previously, as it applies to blooming trees as well. You certainly don’t want to cut off any flower buds on trees that are just coming into bloom. Once again, prune to the ‘fork in the road’, but do not remove the fork! If you leave short stubs, they will end up being dead ends and your tree will have a tougher time healing up. It’s much better to trim them clean at the fork.
Last but not least, if you forgot to trim your ornamental grasses back, you can still go in and selectively trim out those dead blades and plumes, but this is much easier to do in early spring before they start to grow. A trick of the trade we’ve learned after hours of clean up is to snugly tie a light rope around the whole grass and, when you cut it down, it’s all conveniently bundled into one, large bale for disposal.
Vines, such as Climbing Hydrangea, Clematis, Wisteria and Ivy, can get a quick fine tune right now, too. For now simply, clean up any winter dieback as most are beginning to produce flower buds already. Once they have bloomed, you can trim back the spent flower heads and shape the plant for the season.
It’s a really good idea to feed your flowering plants a healthy dose of bone meal, along with a tree and shrub food, to encourage late spring growth. These are easy-to-apply, granular fertilizers that can be sprinkled around the base of the plant. These routine tasks in the garden can make those potentially beautiful specimens even more stunning in the years to come! Feel free to print a copy of this blog and add it to your gardening calendar for years to come! They are also available on our website if you ever need to look back at it!
I hope I didn’t make too much work for you!