Pruning Vocabulary

Each subject has it’s own vocabulary and pruning is no different from the others. The following is a list of terms used in pruning. You may wish to print these out or bookmark it for future reference. Have more questions about pruning? You can ask experts and other HOS members on the HOS Forums!

Apical bud
Terminal bud at the tips of branches, produces auxin.
Apical Dominance
Result of terminal bud producing auxin from the apical bud. Plants that do not form many branched (apples, cherries) produce larger amounts of auxin than those than form many branches (dogwood, oak).
Arm
In grapes, arms are the parts of the vine which are two or more years old, excluding the trunk. In grapes, canes are one-year-old shoots. Shoots grow from these and bear fruit. The following year they are called canes. Head is the area on the trunk from which arms and canes are produced. Spur is a cane, which has been cut back to one or two buds.
Axillary bud (Lateral bud)
A bud in the angle (axil) between the leaf petiole and the stem. Most shoots, branches and spurs. May be a vegetative, fruit or a mixed bud in apple.
Auxin
Plant hormone produced in the terminal bud. Transported in the phloem, located in the bark, from tip to root. Inhibits branching from lateral buds.
Blind Wood
Part of a limb without spur or shoot development, more severe at stem attachment end. Head prune limbs and position more horizontally, stimulates axillary buds.
Bourse
The thickening of the floral bud in apple and pear. Produces swelling at the point of attachment of the fruit.
Branch collar
Swelling at origin of branch, location of healing hormones. Cut at branch collar.
Bud Union
Point where scion and rootstock meet. With size controlling rootstock, a conspicuous swelling may occur at the union.
Cane
In grapes, canes are one-year-old shoots. Shoots grow from these and bear fruit. The following year they are called canes.
Central Leader
A single vertical extension of the trunk from which all scaffold and fruiting branches originate; a single vertical axis.
Crotch Angle
The angle of the limb from the main branch. Strong and more fruit if 60 °, weak and less fruit if 75°. See diagrams on extension.umn.edu.
Flower bud
A bud that produces only flowers.
Girdling
Removal of a section of bark either completely from a branch or partially from a branch. Used to slow branch growth.
Head
In grapes, head is the area on the trunk from which arms and canes are produced.
Heading cut
Removes terminal bud and its auxin production, resulting in 3 to 4 branches from the lower lateral buds.
Leader
A shoot, which has been selected to extend the trunk. May be a single shoot for a central leader tree or several shoots for an open center or multiple leader tree.
Mixed bud
Produces flowers and stem and leaves. Stone fruit trees (peach, nectarine, apricot, plum, and cherry) produce mixed buds.
Notching
Removing a piece of bark. Used to produce branches where you want them. Notching above a lateral bud in early spring prevents auxin from reaching the lateral bud, resulting in a branch.
One-year-old-wood
Used in grafting, the scion, located above the terminal bud scale scars. Some plants only produce fruit on one-year-old-wood such as peaches, grapes and persimmon.
Open Center
A tree form with several, usually three to five equally strong main branches originate from the trunk and are trained to grow upward and outward leaving an opening in the center. Also referred to a vase or open vase tree form.
Pinching
Removal by cutting or with fingers, of terminal bud of young developing shoot. A type of heading cut.
Pruning
Partial or complete removal of vegetative and or fruiting wood from a plat to regulate size, to direct growth, to remove unnecessary wood and to control the balance of fruiting and vegetative growth. See heading, pinching, renewal, shortening, thinning and two-thirds rule.
Renewal Pruning
Pruning a branch two years of age or older at its point of origin on the leader. Used to increase fruiting on younger wood and to improve light distribution into canopy. An alternative is shortening pruning (see 2/3′s rule)
Rootstock
A root system for a fruit tree on which the scion variety is budded or grafted. Rootstock may be used to control tree size, induce fruiting, provided adaptation to specific climate or soil conditions.
Runting Out
Poor tree growth due to early fruiting, over fruiting or weak vigor variety grafting to most size controlling rootstock. (See HOS publication on “Apple Tree Vigor.”)
Scion
A detached shoot or bud of a selected variety used for budding or grafting onto a rootstock.
Shortening Pruning
Removal of par of a branch or limb by pruning into two-year-old or older wood, usually to a weak side shoot or spur. Used to shorten branches to maintain tree form and stimulate growth of remaining wood.
Spreading
Tree training for changing the angle of a branch away from vertical toward or even be low the horizontal. May use sharp-pointed wood or metal braches (spreaders). Can also tie down limbs with strings or rubber bands. For young branches that are less than five inches long, clothespins or toothpicks may be used as spreaders.
Spur
In apples, spurs develop form axillary buds on two-year-old shoots. Spurs often flower the following year. Axillary buds on spurs can give rise to shoots or new spurs. In grapes, spur is a cane, which has been cut back to one or two buds.
Spur-bound
Weak growth of branch or tree with many spurs with little or no annual shoots growth. (See Runting Out)
Terminal bud
Located at the tip of a shoot, all plants grow in length from terminal buds.
Terminal bud scale scars
Scars resulting from the terminal bud scales that fall off that completely circle the stem. Signals one year growth.
Thinning cut
Removal of branches back to point of origin. Cut at branch collar. Alternative is heading cut.
Tip (terminal) Bearing
A type of fruiting habit in which fruiting occurs more commonly at shoot tips than on spurs. Tend to branch higher in the tree and produce long bourse shoots.
Two-thirds Rule
Used to determine which limb to prune. When the limb is larger than two-thirds of the diameter of the main leader, the limb should be removed.
Vegetative bud
Produces stem and leaves.
Whip
A One-year-old tree without branches.

 

Pome News, Winter 2009