Growing Food

When to Prune

The best time to prune most woody plants is during the cold season when they are dormant. If circumstances force you to prune later in the season you aren’t going to kill your plant.

Why Prune Plants in Late Winter?

they are free of leaves and you can see what you are doing
the plant energy isn’t wasted on new growth that is going to be loped off
they are least susceptible to infection at this time (there are exceptions)

Some Basics

1. A tree grows from the top, from its leaders. A branch doesn’t move up a tree as it grows taller. The branches on a small tree will stay at the same height from the ground all its life. It will grow new branches higher up but the original branches will stay where they are.

 

 

 

 

2. Terms used in Tree and Shrub Pruning

 

 

 

 

 

Some Tips

• Sterilize your pruning equipment in isopropyl alcohol after working on each plant.
• The 4 D’s: prune out the dead, diseased, damaged and dysfunctional.
• Most trees and most other plants do not require a lot of pruning– in fact, most of the time, pruning out the 4 D’s is all that is needed.
  Over pruning encourages water spouts (suckering) and effects root growth, growth that is essential to surving harsh climates.
• Remove sucker growth from the base of the trunk and from the interior of the tree annually.
• Any cuts that aren’t made flush to a trunk or branch should be made at least 2 cm (1”) above a bud and cut cleanly with sharp pruners or loopers.
• Don’t stake a tree any longer than one year at which time it’s stable enough to stand on its own.
• Keep mulch away from the trunk of the plant to prevent rot and rodent damage.
• Use well-rotted manure, mulch or compost to nurture trees and shrubs placing it well away from the trunk or crown and concentrating it at the drip line. Over fertilizing with nitrites will inhibit flower budding and cause excess vegetative growth making plants vulnerable to pests. Over fertilized garden centre seedlings reared on chemicals may not survive normal planting conditions.

Pruning Trees (apple, pear)

Full Size Standard Trees (under 10 years of age)

• At maturity a pruned apple or pear tree should be Xmas tree shaped. Identify your central leader. Remove double leaders.
• Choose your lowest branch – in the Haliburton Highlands make sure it is above the snow line (1 metre min.) to avoid ice damage and breakage. Now prune all branches below it.
• Now prune according to the 4 Ds.
• If there are multiple branches you may want to thin some out. You want the tree to be well balanced so choose main branches on all sides first. (mark with ribbon).
• If you need to do further pruning, follow the branch to the trunk and cut on a 45 degree angle above the branch collar (to optimize healing). Avoid pruning branches larger than 8cm (3”). Prune out branches with wide or narrow crotches. The best crotch angle (roughly the 2 o’clock or 10 o’clock angle from the center of the tree). Wider angles can break when laden with fruit and narrower angles lead to bushy growth and fruit that is too high to pick.
  Prune back any lower branches that arch and grow taller than the central leader.
• You can choose at this last stage to give the tree an overall haircut by heading back the long gangly stems to encourage shorter, stouter branches. Cut back 20-30% of last year’s growth. (Avoid creating bushy starbursts in unwanted places)
• Thinning out young fruit: If you have a particularly prolific tree and are concerned that a branch laden with fruit will break and you want larger but fewer fruit and good flower bud development for the next season consider thinning out the fruit. Begin thinning the fruit early when it is 1.5 cm in diameter. Starting at one end of a branch remove fruit, leaving one fruit every 15 – 20 cm (6-8”). Any earlier and you might remove leaf buds by mistake. (This fruit thinning technique applies to pommes and stone fruits.)

 

Check out our Heritage Apple Project here!

 

Pruning Stone Fruit Trees (plum, cherry, apricot)

Stone fruits are native to warmer areas of the world and growing them in Zone 4 is a challenge. They bloom earlier in the spring and can be damaged by our late frosts. They are shallow rooted, prone to drought and disease and harvest is delayed to allow for maximum sweetening. (The sugar content in stone fruit doesn’t increase after harvest.) If you like cherries try growing a Shrub Cherry instead of a tree. They are hardy and blight resistant.
Stone fruit trees are pruned in spring from bud swell to petal drop to avoid infection from canker disease. The central leader is cut to encourage an open vase shape for maximum light penetration.

 

 

 

Notes on Trees

• Although there are newer more cold hardy rootstocks of dwarf and semi-dwarf trees a ‘standard’ height tree will be dependably cold hardy and live for decades. If you’ve ever walked through an old abandoned orchard the trees left standing are standard height heritage apples.
• A tree will develop a stronger, more extensive root system if it has a fuller crown. Limit pruning at the time of planting to structural training and the removal of damaged branches only. Any removal of branches will reduce the capacity of the tree to produce food in the leaves and provide energy for above and below ground growth.
• In most soils, the vast majority of trees’ fibrous, absorbing roots are in the top eight inches of soil. Roots grow where conditions are best for root growth and where water and oxygen are available.
• Taproots are very uncommon in mature trees. If taproots do develop, they usually will be forced into horizontal growth when they encounter bedrock or hard subsoils beneath the surface. The entire root systems of most trees can be found within three feet of soil. The spread of the root system however, can be very extensive, often extending 2-3 times the spread of the crown.

For more information go to: http://www.hardyfruittrees.ca/tutorials/2014/01/20/how-to-prune-a-fruit-tree

How To Prune Your Fruit Trees

 

Pruning Grapevines

Grapevines have to be aggressively pruned in order to yield any fruit. The vine will only produce fruit on the new branches of the year. If you let the vine make five meters of branches every year, after 3 years your vine will have to feed 15 meters of branches in order to reach the branch’s extremity where the fruit is.

Goals of Pruning

1. To obtain multiple clusters of fruit
2. To train the vine along a trellis, fence or conventional 2 wire structure.

When to Prune

Late fall or early spring

Types of Pruning

1. To tame an overgrown Grapezilla
2. Young plants and annual maintenance pruning

The Technique

1. Choose the main stem. It is the strongest stem that comes out of the ground. Then cut all the other stems coming out of the ground, just above the ground.
2. On the main stem, you will have to choose 4 branches. Choose the two strongest branches from both the left and right sides. If supporting your vines with two parallel wires (like shown in the image below) choose your branches so that each of them will easily hang on the wire. Using flagging tape is a great help in identifying the branches to keep. It will also help you to avoid cutting the good branches.
3. Cut all the branches, except for the 4 chosen, to 1cm from the main stem.
4. Finally, on each of the 4 branches, keep two buds and cut off the branch between the second and third bud.

 

About Kiwi

• Male and female flowers are born on different plants, so both males and females must be planted in roughly a 1:6 ratio of males to females.
• The plants often take several years to mature and usually do not bear fruit until they are 5 to 9 years old.
• Although the plants are extremely winter hardy–tolerating temperatures as low as -30°F–they develop shoots early in the spring that are extremely sensitive to frost. In most years, there may be some shoot “burning” due to frost, although the plant usually survives, regrows, and fruits. If flowers are frosted, fruit will not develop that year.
• Hardy kiwi are extremely vigorously growing vines that require a substantial supporting trellis.

 

 

 

 

Pruning Kiwi Vine the First Year

1. For the first year focus on straight growth and a strong framework. Tie the vine loosely to the post and keep it growing straight upward. Don’t allow it to twirl around the post. Remove all side branches until the vine reaches the top of the post.
2. Cut out the top of the vine a few inches below the top of the post and encourage side shoots that grow laterally along the wires. Winter is the best time for pruning kiwi vine side branches along the wires. Cut them back to a point where the stems are about 1/4-inch in diameter. If the vine didn’t form good side branches at the top, cut the main trunk back by about 2 feet and try again next year.
3. After the first year, focus on building strong lateral growth along the wires. Lead the branches near the top of the vine to the wires and fasten them in place every 18 to 24 inches. Cut the vine to keep it from extending beyond the wires. Remove shoots that are twisting around other shoots or taking off in the wrong direction.

 

 

 

 

 

How to Prune an Overgrown Kiwi

1. Remove all of the branches that wind around the kiwi trellis. Also, remove vine sections wound around other branches or nearby plants. Using sharp, sterilized pruners make a clean cut about one inch (2.5 cm.) from the main vine.
2. The next step is to trim out cross branches. This includes branches growing over or crossing other branches. Also, trim out shoots growing straight out from the stem since these will not bear fruit.
3. Select a principal stem for the kiwi vine and train this straight up a trellis. It should get some 6 feet long. Just beyond this point, allow two lateral side shoots to grow over the trellis. Prune these back to three buds, then remove all other lateral shoots.

Read more at Gardening Know How: https://www.gardeningknowhow.com/edible/fruits/kiwi/pruning-kiwi-vines.htm
https://extension.psu.edu/hardy-kiwi-in-the-home-fruit-planting