How to Prune Conifer and Evergreen Trees

By Mary Donaldson

Discover beginner-friendly pruning tips for your conifers and evergreens.

Dr. Bert Cregg demonstrating how to make a cut during pruning
Dr. Bert Cregg demonstrating how to make a cut during pruning

Do you ever wonder who was allowed and why they were allowed to prune a tree or shrub? Then do you wonder if that same person would be allowed to cut someone’s hair?

Just as one learns to cut hair well, it takes instruction and lots of practice to maintain a tidy look and style to landscape trees and shrubs. Pruning conifers requires a bit more awareness, as they can be less forgiving when done incorrectly.

Before approaching a landscape tree or shrub with something sharp in hand, it is important fi rst to be truthful about one’s knowledge and skills. The fear of doing something wrong is a good caution, but should not be a reason to do nothing.

Before and after pruning
Before and after pruning

Pruning Conifers with Purpose in Mind

“That is how things get way out of shape and out of bounds,” said Wayne Strayer, from Hidden Lake Gardens, located in Tipton, Michigan. He has spent the last three years of his 35 years in the green-industry, working on the Harper Collection of Dwarf and Rare Conifers. “Most people don’t prune because of fear.”

Pruning the plant when it has broken branches, disease, reversions or has become too big, are the most common reasons. In all circumstances, prune with a purpose in mind. With specimens, there is one main reason for pruning which can also be utilized with any planting in the home landscape.

“Maintain the shape of the plant,” said Jim Chamberlain, who has spent the last five seasons working in the Harper Collection at HLG. “I felt like I had been asked to watch over a celebrity,” Chamberlain said, recalling back to when he was given the responsibility of working in the Harper.

Pruning for a conifer's health
Pruning for a conifer's health

Pruning Like Nobody Knows We Were There

Initially, he was intimidated, but asked a lot of questions before doing anything. It took time to build his confidence up to where, Chamberlin very modestly explained, he can provide input on Harper maintenance.

His goal is to prune so that “nobody knows we were there.” This author’s personal primer has been Adrian Bloom’s book, Gardening With Conifers, which devotes a section to pruning and shaping conifers. Other books on pruning are available for purchase or checking out at a local library.

Caution is advised that some of these books may not be as detailed for someone who is trying to DIY, or may find the material is geared more toward professionals.

How to snip branch tips back lightly on a conifer
How to snip branch tips back lightly on a conifer

Pruning 101 with Horticulture Experts

For those who are inclined to learn visually, the site, is recommended.

The website offers links to videos with step by step directions, showing the finer nuances of pruning. Additionally there are articles which supplement the videos, both featuring Bert Cregg, Associate Professor of Horticulture at Michigan State University.

Cregg gives clear and understandable directions on why to prune, when to prune and how to prune. Control pruning is important to do with plantings in the first couple of decades. Strayer stated that he sees so many trees which have to be removed when they get too big. By being proactive instead of reactive, pruning can be used to prevent problems.

Chamberlain agreed, and added that getting to know the personality of a tree or shrub is important. Chamberlain described how some can be pushy to their neighbors or “namby-pamby," his term for needy.

By combining the knowledge of controlled pruning and plant habit, specimen plantings will most likely have a longer life. “If they had been pruned years back,” Chamberlain said, “they could have stayed, but they were making dead spots on their neighbor.”

How to make a cut half an inch or so above a bud on a conifer
How to make a cut half an inch or so above a bud on a conifer

Finding your Pruning Tools

More advice for the newbie is using the right tool and maintaining them. “Hedge clippers,” Strayer said, shaking his head and putting his arms up defensively, “Hands off.”

For professionals and the obsessed, bypass pruners are key in making clean cuts with live stems or branches. The blade is able to pass by the guide, creating cuts which will heal more quickly and be more aesthetically pleasing.

Anvil type pruners have a blade which stops when it makes contact with the flat cutting surface. Using this on live branches can crush part of the stem or branch tissue. It can also cause tears and create more contact area for pest and disease problems.

“Stay away from the anvil, they are just mashers,” Strayer said. “Avoid buying cheap pruners, they (good quality pruners) are a good investment. Keep them sharp.”

How to trim back the outermost tips to encourages fullness in a conifer plant
How to trim back the outermost tips to encourages fullness in a conifer plant

Keeping your Pruning Tools in Shape

Keeping tools sharp will make the job not only easier, but will minimize self-injury and less damage to plant pruning. Sanitation between pruning different plants is essential to minimizing the spread of disease. Simple bleach solutions or alcohol swabs are easy enough to become routine.

Guidelines for the right size tool for the stem or branch is 1” in diameter or smaller, pruners will work, while loppers will be best for 2” or larger. Anything thicker, select a hand saw. Cutting the branch back as much as possible before the final cut will lower the weight load and make the work less unwieldy.

Additionally, to decrease damage to the rest of the tree or shrub, make a preliminary cut on the opposite side of main cut to minimize splintering and bark tear.

How to lightly trim back the outermost growth using hand pruners or hedge shears
How to lightly trim back the outermost growth using hand pruners or hedge shears

Finding Hands-On Pruning Practices

Other ideas for building confidence in pruning is to look for hands-on pruning classes through community colleges, botanical gardens, and Master Gardener programs which will provide more practice and instruction. Inquiring at a botanical garden or reputable nursery staff in the off-season for general questions can be helpful.

“You can take off more,” Strayer warns, “but you can’t glue it on.” Everyone has their methods of pruning. Hands-on practice will be the best training. Finding out what others use for guidance will also help as pruning is one part tool and many parts philosophy.

“When you’re pruning,” Chamberlain said, “step back and look at what you’re doing.” This was the advice he was given when he first started working in the Harper Collection.

“The worst time to prune is never,” Strayer said.

This article was originally published in the Summer 2014 issue of Conifer Quarterly. Join the American Conifer Society to access our extensive library of conifer-related articles and connect to a nationwide group of plant lovers! Become a member for only $40 a year and get discounts with our growing list of participating nurseries in our Nursery Discount Program.