Fruit tree pruning is a necessary skill to have to raise healthy, productive fruit-bearing trees. My guest this week, Susan Poizner, is an urban orchardist and author who joins me to explain when and how to prune fruit trees for the best results.
Susan is the director of Orchard People Fruit Tree Care Consulting and Education in Toronto, Canada, and the founder of OrchardPeople.com, where she offers articles and courses on raising fruit trees. She trains thousands of new growers worldwide through her fruit tree care training program, and is also an International Society of Arboriculture-certified arborist. She also has an award-winning podcast, “Orchard People.”
Urban orchardist Susan Poizner is the founder of OrchardPeople.com and the host of the “Orchard People” podcast. Photo credit: OrchardPeople.com
Susan has two new books out: “Growing Urban Orchards: How to Care for Fruit Trees in the City and Beyond” and “Fruit Tree Pruning: The Science and Art of Cultivating Healthy Fruit Trees,” the latter of which is the subject of our discussion this week. (Susan will be back soon to discuss urban orchards.)
I’m so glad to have Susan as a friend. She has unique expertise in fruit trees and excels at teaching the rest of us how to take care of them and get over the intimidation factor. She dispels myths and helps us realize we can do this.
“Once you understand the science, it’s not hard to prune fruit trees. It’s actually quite intuitive,” Susan says.
Fruit trees seem to be more receptive or more responsive to proper pruning than almost any tree I can think of. Susan promises that whatever tree you have, even if you planted it 10 years ago and you’ve neglected it, you can still revitalize it with pruning.
“When you’re growing fruit, it’s a collaboration between you and the tree,” she says. “These trees are not wild. They are grafted. They’re two different trees. They’ve got the root stock, they’ve got the top of the tree. They need us in order to create beautiful, delicious, healthy fruit. Otherwise they will grow however they grow, they’ll get diseases, they’ll be small fruit. It might not taste so good, but so we can work together to create a healthy harvest and a healthy tree.”
Before continuing with my conversation with Susan Poizner, I want to take a second to invite you to attend the Ecological Gardening Summit on Wednesday, May 7, at noon Eastern. Learn sustainable gardening practices and connect with fellow green thumbs. I will be hosting, and joining me are Dave Goulson, Nancy Lawson and Benjamin Vogt.
How Susan Became an Urban Orchardist
“I am a person who didn’t do any gardening until I was in my 30s,” Susan says.
It was after she married her husband, Cliff, who is originally from Trinidad, that she began gardening.
“In Trinidad, you eat a fruit, you just throw the seed down, you get an amazing tree, you get plants. It was so natural to him, but for me it wasn’t natural,” she says. “And when he wanted to plant out our backyard with all sorts of stuff, I was really resistant. And I’m one of these people, I have to see it to believe it. So the garden started to bloom, and the food we were growing was amazing.”
She loves vegetable plants but as she started her gardening journey, she gravitated toward trees.
“The more I learned about nature, the more I was fascinated with trees, and especially fruit trees, because trees do so much,” she says. “They clean our air, they stabilize the soil, they beautify our environment, but these fruit trees can feed us too. So I became very fascinated with fruit trees and I actually enrolled in a landscape design course.”
She loved that course, especially learning about designing with trees. At the same time, she wondered what she could do about a local City of Toronto park that nobody ever went to.
“It was kind of ugly. It was not a great place, and I started to think, what if we plant fruit trees there?” she recalls.
She thought fruit trees were easy and took care of themselves, but she soon learned that isn’t the case. “I didn’t realize that they can be tricky,” she says.
Within a couple of years, the problems started, namely diseases and poor production. She needed to get to the bottom of how to turn things around. She leaned on her years of experience as a journalist, radio producer and television producer, and leveraged her research skills.
She wrote her award-winning fruit tree care book “Growing Urban Orchards,” based on her experience founding that orchard — the Ben Nobleman Park Community Orchard.
Why the Youngest Fruit Trees Give You The Best Start
Susan compared planting a grafted fruit tree to teaching a child a new language. The younger they are when you get started, the easier it will be. A 1-year-old fruit tree whip — all it looks like is a branch with roots — is more adaptable to a new environment than a years old potted tree from a nursery.
“A lot of people will have big trees, and then you have to improvise with what you’ve got,” Susan says. “But if you are sculpting with that little young tree, you can create one of the ideal structures for fruit production and for tree health.”
When Susan began the community orchard in 2009, she didn’t prune them for two years.
“They start growing every which way,” she says. “By the time you prune them, the branches are more set. They’re lignified, they’re sort of more woody, and so you’re making more of a wound in the tree. Whereas if you start with these nice soft branches, you can basically sculpt the perfect structure.”
Susan plants a fruit tree whip.
Photo credit: OrchardPeople.com
When to Prune a Fruit Tree
Late winter pruning stimulates growth. Summer pruning slows it down.
Pruning ideally starts when plants are very young, though you may come upon a mature but neglected fruit tree.
“Do you want your tree to grow fast and grow up to be big and strong? Or do you have a big old apple tree or a big old cherry tree that’s already too big and you want to make it smaller?” Susan asks. “That’s how you’re going to make your decision when to prune the fruit tree.”
If you want to encourage growth and you want a faster-growing tree, you will prune in the dormant season — the late winter or early spring. If you want to slow down growth, you will prune it after blossom time, in the early summer.
Susan breaks down the science behind choosing when to prune by using a metaphor: A tree’s root system is like its pantry.
A little whip with 10 buds will divide what’s stored in the pantry 10 ways. “What happens if you remove the top three buds?” Susan asks. Now, the same amount of energy is split only seven ways. The remaining branches will grow longer and stronger.
If you waited too long to prune in spring and now a fruit tree is starting to leaf out, there will be less energy remaining in the root system, Susan explains. If you prune then, you won’t have as vigorous growth, but you’ll still have vigorous growth. If you wait until a fruit tree has created a few blossoms then prune, there will be even less stored energy. And if you wait until the tree has started forming fruit, there won’t be much left in the root system.
“The tree has run a marathon,” Susan says of summer pruning. “It’s burnt up almost all the energy in its root system. At that point, you don’t enjoy the benefit of vigorous growth. … When you prune after blossom time, you’re in a way slowing growth because the tree doesn’t have that energy.”
Once a tree has leafed out and blossomed, it is producing energy through photosynthesis and is putting that energy into activating buds and fruit production.
If a tree is big and overgrown, summer is the best time to prune. Up to 25% of the living canopy of a healthy tree can be removed. Susan advises inspecting the tree before it has leafed out, determining what can be cut off to improve the structure, and marking those future cuts with flagging tape so you can locate them again in summer when the tree is covered in leaves.
Susan’s first teacher, Norm Herbert, told her, “Susan, sometimes one good cut is better than a thousand little ones.”
If you make those cuts in later winter or early spring, when the tree’s dormancy breaks, the tree will pour its stored energy into the branches that remain. This will encourage the tree — especially an apple tree — to grow non-fruiting water sprouts.
Water sprouts also appear any time you overprune. The tree will not be happy and will produce more water sprouts, with lots of leaves, so it can produce more energy through photosynthesis.
This is a good reminder of why you should not top a tree. When you top a tree, it will shoot up ugly water sprouts in an effort to survive, and after it’s been topped again, it will eventually die from the stress.
Timing is important and will be different depending on your pruning goals.
Photo credit: OrchardPeople.com
How Hormones Influence Growth and Pruning
In the winter, the main hormones that are active in fruit trees are auxin hormones, Susan says. Auxin hormones are on the growing tips of the branches, and they basically say to the branch, “Let’s grow long.”
Auxin hormones suppress the lateral buds on a branch. This causes the branch to grow only from the tip and not from the sides.
“So you get these long, willowy, slender branches with not a lot of side action happening,” Susan says. “And when a tree is young and small, you want that because you want to create a structure.”
As the season progresses, auxins settle down. Another class of hormones, cytokinins, become active, and they say, “Let’s develop fruiting buds.”
“Once you miss that window of late-winter, early-spring pruning, it’s not a disaster, it’s not a problem,” Susan says. “You’ve just lost a little bit of momentum in terms of creating the shape for your tree. You can still prune in the early summer and you still get some benefits. You’re still shaping the tree. But it just sort of works in a different way.”
When the tip of a growing branch is removed, the lateral buds grow.
Why Fall and Winter Are Bad Times to Prune Fruit Trees
In fall, a tree gets ready for dormancy. The leaves turn brown as the tree takes the nutrition and energy from the leaves all the way into its trunk and down into the root system for winter storage, Susan says.
If you prune in the fall, the tree will not be actively growing and won’t be able to heal those wounds. But if you prune during the growing season, within hours, cells become active and cover and protect the wound. “And then over the years you’ll see that it actually closes up,” she says.
An open wound during freezing temperatures can damage cells inside the tree. But if you can wait until later winter to prune, the trees will soon emerge from dormancy and begin to heal those wounds.
Midwinter is a bad time to prune. At an orchard with 10,000 trees, there’s no choice but to prune throughout winter. However, a homeowner with only a few trees can wait until late winter or early spring.
“What you want to avoid is the deep freezes, the times where the temperatures get really, really low, where the damage can happen,” Susan says.
Sculpting Fruit Trees
Susan explains that there are two main structures considered to be the best for fruit tree health and production, vase-shaped and central leader.
A vase-shaped tree has about five branches coming out of the trunk, each in a different direction.
“Each of those branches will then subdivide twice, so it’s actually like a beautiful bowl or a plate,” Susan says.
The vase shape can be achieved when starting with a whip.
“If you start in year one, you plant that little tree and you give it what’s called a whip cut, which is cutting off the top one third of the tree at least,” Susan says.
Cutting off that third gives the remaining two-thirds more energy to make branches. At the cut, about 36 inches off the ground, the tree will divide into what will become a cup shape. In year two, determine which branches will be the perfect scaffold branches.
If you have three branches and they’re all growing close together in the same direction, you will not get the benefit of a big beautiful bowl where every branch has access to sunshine and good air circulation, Susan says. Those are what a fruit tree needs to stay healthy and productive. Sunshine helps the fruit ripen property and the leaves can photosynthesize to the maximum. Air circulation reduces pathogen issues.
Once you determine the branches to keep, the rest can be cut off. This is called formative pruning, which will continue in year three to create an airy, beautiful, strong, firm structure.
Every year after that, it never gets boring, but it’s not as exciting as the formative years, Susan says.
Central leader is a pruning strategy where the tree is trained into a Christmas tree shape, with one central trunk or stem and multiple horizontal branches at the sides.
Each branch should grow in a different direction to avoid crowding and promote air circulation and light penetration.
Pruning After the Formative Years
After the third year, fruit trees have achieved the ideal structure, and there’s still work to do.
Water sprouts, which are upward branches that crowd the canopy and shade the other branches, should be removed. Also remove downward branches and crowding branches.
“We just clean up the structure at that point,” Susan says.
If you have a tree that does not have a good structure, you can make some selective cuts to clear out space for air circulation and allow the sun to penetrate.
“Usually the cuts won’t be shortening the branches. What you’re not doing is taking your tree in the backyard and turning it into a lollipop and shortening all the branches,” Susan warns. “That will make an even bushier tree. It is not going to work for you. Usually what you end up doing is go into the canopy and remove some of the branches carefully and judiciously right to the trunk. You remove the branches, the lateral branches attached are also gone, and it opens up air circulation.”
The Two Most Important Cuts to Know to Prune Trees
There are only two cuts you need to know to prune a fruit tree: the thinning out cut and the heading back cut.
“Heading back is shortening a branch, and thinning out is removing a branch to its origin,” Susan says.
Every big branch has a collar at the trunk that looks like a turtleneck. Cut this far back to make a thinning cut. “Where you cut is just past the turtleneck to keep that turtleneck in place because the turtleneck will heal the wound,” she says. “That’s where the cells are that will heal the wound.”
When heading back, cut a quarter of an inch past a bud. Too close to the bud can damage the bud, and too far from the bud will leave a dead tip behind.
When cutting a branch off completely, cut all the way back to the collar but don’t cut the collar itself. The collar will heal the wound. This is tree of fruit trees and landscape trees.
I hope you enjoyed my conversation with Susan Poizner on fruit tree pruning. If you haven’t listened yet, you can do so now by scrolling to the top of the page and clicking the Play icon in the green bar under the page title.
What has raising trees taught you about fruit tree pruning? Let us know in the comments below.
Links & Resources
Some product links in this guide are affiliate links. See full disclosure below.
Episode 096: Tips for Fruit Growing Success: Selection, Maintenance & Advice, with Dr. Lee Reich
Episode 138: Why Pruning Matters: Principles, Recommendations and Tips from the Pruner’s Bible
Episode 215: Roots Demystified: The Amazing Unseen Things Roots Do
Episode 246: Growing Figs Anywhere, Even in Cold Climates, with Lee Reich
Episode 344: Grow Fruit Trees Successfully
The Ecological Gardening Summit – Wednesday, May 7, at noon ET – Join us at the Ecological Gardening Summit to learn sustainable gardening practices and connect with fellow green thumbs!
joegardener Online Gardening Academy™: Popular courses on gardening fundamentals; managing pests, diseases & weeds; seed starting and more.
joegardener Online Gardening Academy Organic Vegetable Gardening: My new premium online course. The course is designed to be a comprehensive guide to starting, growing, nurturing and harvesting your favorite vegetables, no matter what you love to eat, no matter where you live, no matter your level of gardening experience.
joegardener Online Gardening Academy Master Seed Starting: Everything you need to know to start your own plants from seed — indoors and out.
joegardener Online Gardening Academy Beginning Gardener Fundamentals: Essential principles to know to create a thriving garden.
joegardener Online Gardening Academy Growing Epic Tomatoes: Learn how to grow epic tomatoes with Joe Lamp’l and Craig LeHoullier.
joegardener Online Gardening Academy Master Pests, Diseases & Weeds: Learn the proactive steps to take to manage pests, diseases and weeds for a more successful garden with a lot less frustration. Just $47 for lifetime access!
joegardener Online Gardening Academy Perfect Soil Recipe Master Class: Learn how to create the perfect soil environment for thriving plants.
“Orchard People” podcast
“Grow Fruit Trees Fast: A Beginner’s Guide to a Healthy Harvest in Record Time” by Susan Poizner
“Growing Urban Orchards” by Susan Poizner
“Growing Urban Orchards: How to Care for Fruit Trees in the City and Beyond” by Susan Poizner
“Fruit Tree Pruning: The Science and Art of Cultivating Healthy Fruit Trees” by Susan Poizner
Urban Forestry Radio on Apple Podcasts
Territorial Seed Company – Our podcast episode sponsor and Brand Partner of joegardener.com
Soil3 – Our podcast episode sponsor and Brand Partner of joegardener.com
Proven Winners ColorChoice – Our podcast episode sponsor and Brand Partner of joegardener.com
Milorganite® – Our podcast episode sponsor and Brand Partner of joegardener.com
Disclosure: Some product links in this guide are affiliate links, which means we get a commission if you make a purchase. However, none of the prices of these resources have been increased to compensate us, and compensation is not an influencing factor on their inclusion here. The selection of all items featured in this post and podcast was based solely on merit and in no way influenced by any affiliate or financial incentive, or contractual relationship. At the time of this writing, Joe Lamp’l has professional relationships with the following companies who may have products included in this post and podcast: Corona Tools, Milorganite, Soil3, Territorial Seed Company, Earth’s Ally, Proven Winners ColorChoice, Farmer’s Defense, Heirloom Roses and Dramm. These companies are either Brand Partners of joegardener.com and/or advertise on our website. However, we receive no additional compensation from the sales or promotion of their product through this guide. The inclusion of any products mentioned within this post is entirely independent and exclusive of any relationship.
