By David Knopf, News Editor
There’s ample opportunity for a grower to artfully shape fruit trees, but self-expression is best pursued
with an understanding of the science behind pruning for healthy growth and production.
was the message delivered by University Extension Horticulturist Marlin Bates, who led a pruning workshop Feb. 17 at Of the Earth Orchard in northern Ray County. The group met in a barn at the seven-acre organic orchard operated by James and Patricia Pierce, who are assisted by their oldest son, Jim.
“You’re free to make the art of cuts anyway you like, as long as you use this science,” said Bates, who used slides to illustrate his talk before leading a group of 15 into the orchard for a demonstration. “We want to look at what is pruning and what is training, what’s the difference, and which way we
want to go.”
Based in the University Extension office in Platte City, Bates defines pruning as the “judicious removal of shoots or branches of a tree to increase its economic value.” Shaping refers to the tree-keeper’s choice of the appearance – for example, avertical axis or narrow pyramid shape for an apple tree or an open shape for a peach tree.
The idea, according to Bates, is to find a balance between the need for vegetative growth – encouraging the development of “fruiting wood,” i.e. branches that are exposed to light and nutrients and will bud in the future – and having a harvest of fruit in the current year.
Training a tree in the first several years and then pruning it each year after is how a grower can increase productivity and economic value, Bates said. It’s also a time to pursue whatever aesthetic ideal a person envisions.
Bates defined shaping a tree as developing its structure by training limbs and branches; estimating the weight of fruit and how fruit-bearing branches will fall on the branches below; maximizing the distribution of sunlight; and annually pruning limbs and shoots that are counter-productive.
Bates said that pruning helps a tree develop a strong structure, promotes flowering and fruiting, directs growth and utilizes space efficiently. Removing dead or diseased wood, or shoots and branches that block light and absorb energy needed elsewhere, will improve a tree’s chances of survival after transplanting, as wel
l as help rejuvenate an older tree.
Bates took the workshop students into the orchard and used an apple tree and a peach tree to demonstrate pruning and training techniques. The correct pruning angle is 20 percent, which Bates said stimulates vegetative growth behind the cut. It’s best not to make pruning cuts too long or too sharply slanted, he said, in order to reduce the chances of disease and to speed up the healing process.
The ideal angle for any new growth – a shoot – is around 60 percent from an existing branch. Other shoots should be snipped, Bates said.
“Shoots that are going straight up aren’t going to be fruitful for you,” he said.
A spreading tool or tree weights can be used to shape growth to the ideal of 60 percent, s
A goal of pruning is to increase the amount of sunlight that comes in contact with a tree’s growing surfaces.
“One of the things we want to do is to subject it (the wood) to the sun,” Bates said. “You want to make sure you’re
exposing the wood to the sun and developing a successful canopy.”
It’s common sense that sunlight will strike the top of a tree more than lower growing surfaces. The artful science of pruning and thinning helps “disseminate that to the rest of the tree,” said Bates.
Fruit trees require annual maintenance pruning to remove dead wood and upright sucker growth, the horticul
turist said. With apple trees, the ideal is narrow, pyramid-shaped growth, not a wide, unmanagable shape. But Bates said that peaches and other stone fruit trees thrive with an open center shape, ideally with three branches heading out from the center in different directions.
Bates said it’s easy to prune too little, but it’s also potentially harmful to stress a tree by over-pruning.
“You can weaken a t
ree,” Bates said, and eventually overstress and kill it.
onset of spri
ng – just before bud break – is the ideal time for pruning, he said, since it can harm a tree by exposing new cuts to an unexpected freeze or excessive moisture.
Bates introduced a variety of pruning and shaping tools, including anvil pruners, loppers and straight
and curved saws. Although he covered a lot of ground in his 90-minute presentation, Bates said that pruning and shaping trees isn’t as complicated as it might seem.
“You can read a novel about Johnny Appleseed,” he said, “but you don’t need to read a book about pruning.”
the orchard’s co-owner, said his family’s decision to begin growing fruit trees in the early 1990s wasn’t well planned out. He said that after purchasing the small acreage, his son Jim presented the couple with a housewarming present of several heirloom apple trees. They were planted alongside Patricia’s herb, vegetable and flower gardens.
“We did this on a whim,” he told the workshop class. “Didn’t do any research. Bad mistake. We just kind of messed around.”
The Pierces have learned by trial and error. Today they grow different varieties of apple, Asian pear and peach trees. In all, the couple have around 600 fruit trees and sell their produce at farmer’s markets. James said their immediate plans include developing a distillery so they can use their apples to make brandy.
Missouri Extension has information on pruning, shaping and other fruit tree subjects on its Web site at www.extension.missouri.edu/Platte.
Bates will lead a second pruning workshop on March 10 at Allredge Orchards in Platte City. You can contact him at plat...@missouri.edu or call 816-270-2141.
Learn more about Of the Earth Orchards and read the tree-keeper’s blog at www.ontheearthfarm.com.