One of my favorite things about well-kept landscapes and gardens are healthy shrubs. I think that in many aspects, homeowners and landscapers forget about the shrubs- like they’re a plant and go, leave alone part of landscaping, which couldn’t be furthest from the truth. To make your landscape a cut above the rest, knowing how to trim your shrubs properly is an indispensable skill that you should familiarize yourself with. Not only will your yard thank you, but down the road you’ll save money from having to replace unhealthy and unruly shrubs that could have been saved with the proper maintenance.
There’s a plethora of tools out there for you to choose from, each kind specialized for a different task in trimming and pruning your shrubs. Most notably, you’ll notice that these tools all have a curved cutting blade, designed for easily cutting through smaller trunks and branches. Some are designed to cut high branches while you stand on the ground without the aid of any kind of ladder or stool. Some are designed to create topiary shapes into shrubs. Some are made to cut down individual canes of old wood, which is typically done to keep a shrub looking fresh and new each year, and to keep them from growing too large in the landscape. Shrub shears are straight, appearing like large scissors. These are good for making quick work of yearly trimming on most shrubs, making them the most versatile tool for trimming. The very best thing you can do for your tools it to make sure that they’re kept sharp and clean, using specially made sharpeners for landscaping shears and using a disinfectant between uses or even individual shrubs as you work.
Before you are ready to begin, you’ll need to understand what your shrubs need in the way of trimming. There are some exceptions, but generally speaking ornamental shrubs that bloom in the spring such as lilacs, azalea/ rhododenderon, weigela, mock orange, viburnum, forsythia, and bush honeysuckle need to be trimmed right after blooming. Shrubs that bloom in the summer or fall such as hydrangea, late varieties of spirea, hibiscus, summersweet, buddleia, clethera, and crape myrtle should be trimmed in early spring. This also applies for shrubs that are used mainly for their foliage, like boxwood, barberry, dogwoods, and holly.
There are five basic types of cuts you can make, each having different results on future growth of your shrub.
1. Pinching back: Simply use your fingers to pinch off the terminal bud of the branch. This will encourage lateral branches to form and can be a great way to prevent more pruning later on.
2. Heading back: This method removes the terminal bud, resulting in more branches. Cut the branch at an angle, about ¼” above a branch bud and sloping down and away from the bud. The bud nearest the cut determines the direction the branch grows, with the outward facing bud usually resulting in the best shape. If a heading cut is made in the middle of a branch with no bud, the result will be a flush of growth at the site of the cut.
3. Thinning: Thinning involves removing branches while leaving the terminal bud. Make the cut just outside the branch collar, which is the bulge where the branch meets the stem, but don’t leave a stub. Thinning can produce a more open, shapely plant, without altering its overall size, shape, or growth habit.
4. Renewal or rejuvenation pruning: Renewal pruning involves removing the oldest stems and branches at the base, then thinning or heading back the younger stems to promote regrowth. With rejuvenation pruning, the entire shrub is cut to stubs less than 12”. This drastic measure is usually done if a shrub has become an overgrown, tangled mass that is not blooming well.
5. Shearing: Shearing involves trimming off the tips of branches. Shearing alters the shrub’s natural shape and promotes thick growth only on the exterior of the plant, which results in dead foliage and lack of growth on the interior branches.
There are a few schools of thought when it comes to approaching trimming of your shrubs. Personally, I find it to be an enjoyable and forgiving task that allows a lot of room for making mistakes and learning from them. With a little patience and time, teaching yourself how to trim will become an intuitive task and will become one of the best ways to rejuvenate your landscape or garden.