Pruning Trees And Shrubs - University Of Arizona
Pruning Trees and ShrubsJeff Schalau and Ursula SchuchUniversity of ArizonaCooperative Extension
Pruning is the intentionalremoval of parts of aplant for a purpose.
Pruning Equipment
Why Do We PrunePlants?To remove damaged/broken branchesTo remove rubbing, crossing, inwardlygrowing branchesFor visibility & safety considerationsTo train young plantsControl plant sizeRejuvenation of plantsIncrease flowering, fruiting and vigor
Removing BranchesLocate the branchcollarMake first cut frombelowMake second cutfrom above andoutside of first cutMake final cut topreserve branchcollar
Pruning BasicsHeading vs. Thinning
Branch Angles and Removal45 to 60 degrees is a good angleThe branch you cut back to should have adiameter of at least half that of the branchto be removed
Branch SpacingVertical spacingshould allow forradial branchgrowthRadial spacingshould be asbalanced aspossible
Pruning BasicsNever remove more than 1/3 of thecanopy in any given yearIf the plant requires frequent pruning, thenit may not be the best suited plant for thatsituationUsually best done in the early life of theplantShearing is a lot of work and generallyunnecessary
Topping trees is bad because:1. It is a source of invasion by rot-causing organisms.2. It reduces the food producingcapacity of trees.3. New limbs that originate near thecuts are weakly attached and breakeasily in the wind. A re-grown limbnever has the structural integrityof the original limb.
Topping trees is bad because:4. Thick re-growth of suckers orsprouts has greater wind resistanceleading to more storm and winddamage.5. Topping does not help in keeping atree smaller or lower in height6. It’s expensive to have the tree retopped every few years due to rapid,thick re-growth of branches.
Topping trees is bad because:7. It’s ugly! The re-growth of a mass ofstraight suckers and shoots.8. It makes you and your employerlook bad. Informed people know thattopping is not an acceptedprocedure
How Can You Reduce the Sizeof a Tree?Use a technique called ‘crownreduction’. Cut limbs back tolaterals that are at least 1/3 thesize of the parent limb.
Pruning ShrubsMaintenance begins at planting andpruning should begin before the plantreaches the desired sizeSlow growing shrubs normally have a welldefined branch structureShearing should be avoidedFast growing shrubs generally have manyshoots originating at the base of the plantand require regular pruning
Other Shrub Pruning ConceptsVisualize what the plant will look like with thebranch in question removedNever remove more than 25-30% of the oldbranches annuallyIf the plant must be drastically reduced in size,reduce it over a 3-4 year periodMake cuts on shrubs at varying lengths in orderto leave the shrub with a textured natural lookFast growing plants such as Oleander can bepruned to within 6 inches of the ground and willre-sprout rapidly
HedgesChoose evergreen plants with small leaves,short internodes, dense branching and thatare able to sprout from old woodKeep the number of hedges to a minimumbecause they are labor intensive
How to Prune Shrubs1. Know the flowering period for the shrub2. Prune after bloom period3. Try not to remove major branches whichwill open up the plant to sunburn4. Keep pruning to a minimum5. If you find that the shrub requirescontinual pruning, consider removing theplant and replacing with a slower growingspecies
6. Remove dead flowers ‘deadheading’as soon after bloom as possible toreduce seed production and litter7. If possible, attempt to cut above a budon the stem
Alternate BudsOpposite Buds
Pruning summer and fall flowering shrubsPrevious seasons growthNew growth in late springand summerPrune back early in springFlowers bloom onnew growth
Pruning spring flowering shrubsPrevious seasonsgrowthFlowers bloomin springPrune back after floweringFlowers fade,set seedNew growth in summer
Why Not Shear Shrubs?1. It looks unnatural2. Flower production is decreased3. It is very labor intensive4. Plants soon become woody on theinterior5. Height is more difficult to control6. Design intent is lost
How to Avoid Shearing Shrubs1. NEVER use hedge shears.2. Selectively cut branches, cut justabove a bud or side shoot.3. Remove stems throughout the plant.4. Cuts can be as severe as youdesire.
Naturalistic Shrub Pruning1. Cut branches back to a rough globe shape.2. Cut every other branch back 6-9 in. to thefirst large V.
How to Rejuvenate Large Shrubs1. Cut shrubs to 6-12 inches aboveground.2. The ‘stumps’ will re-sprout inseveral months.3. Thin out the number of shootsthe second year and reduce theoverall height by half.
4. The result will be a full,vigorous, rejuvenated shrub5. Not all species respondpositively to this treatmentThis technique does not work with allshrubs. Typically fast growing plantsrespond to this radical pruning
Pruning grassesCut back to 6 in.Above ground in latewinter when grass isdormant.Plants producevigorous new growthin spring.
RejuvenationRemoving old orcrowded stemsfrom multistemmed shrubs
Pruning rosesWhen? Prune in late winter when budsbegin to swell.What? Remove dead wood. Remove crossing branches rubbingagainst others. Remove old, unproductive canes.
Remove one third to no more thanone half the length of previousseason’s growth. Remove suckers. Keep center of shrub open.
Hybrid tea and grandifloraHybrid teas have large flowers, one perstem, and are 2-6 ft. tall. Most popular.Grandiflora (hybrid tea x floribunda) havehybrid tea-type flowers, good for mass color. Leave 5-8 canes, more on vigorousshrubs. Cut back to a height of 18 to 24 in. Cut back new canes by one third.
FloribundaFloribunda (hybrid tea x polyantha) produceflowers in clusters on vigorous, bushy plants.Good for mass color, hedges, informalborders. Leave as many strong new canes asplant has produced. Cut back previous season’s growthonly by one fourth. Can be pruned to hedge effect.
The Bad and the Ugly
Slow growing shrubs normally have a well defined branch structure Shearing should be avoided Fast growing shrubs generally have many shoots originating at the base of the plant and require regular pruning. Other Shrub Pruning Concepts. Visualize what the plant will look like with the
Pruning Trees & Shrubs General Pruning Techniques 2 Spring If extensive pruning takes place before spring growth, cold injury may be a problem. Postpone pruning until growth begins in spring or chance of extreme weather is past. Investigate the influence of timing on infection and development of various vascular or foliar diseases and the
Channel pruning (or structured pruning, filter pruning) is one of the approaches that can achieve the acceleration of convolutional neural networks (CNNs) [10,18,30,32,40]. The goal of this paper is to conduct an empirical study on channel pruning procedure that is not paid enough at-tention to, i.e. random channel pruning. By random prun-
handbooks on useful trees and shrubs in eastern Africa. The aim of the series is to provide information for subject-matter specialists, extension workers and farmers on the trees and shrubs that have a production and conservation potential for small farmers in the region. The volume on Ethiopian trees and shrubs was published in 1993. The
Trees and Shrubs of the Maldives Introduction The human race depends on forests, trees and other vegetation for its survival and well-being. Women, men and children are attracted and attached to trees, shrubs, herbs and other vegetation for various reasons and purposes. Some trees are culturally valuable and some others are
Spring-flowering shrubs bloom on one-year-old wood (twigs that grew new the previous summer). Buds develop mid-summer through fall for the following spring. Pruning in the fall and winter removes flowering wood with buds. Spring-flowering shrubs can be rejuvenated or thinned (as described below) in early .
Structure Developing a preventive pruning program requires that managers be familiar with the techniques of structural pruning. Structural pruning should be practiced for the first 15 to 25 years of a tree's life. This is the amount of time required to establish strong structure in the canopy and will help to make the tree more resistant to storm
Creating Small Trees from Shrubs Raise lower canopy Essentially, follow your guidelines for shade tree pruning Can give a really neat appearance. Pruning Pagoda Dogwood. Hedges and Screens Formal vs Informal Hedge Formal is sheared Informal is usually naturally pruned Goal is to retain
There are three levels of classification: "TOP SECRET", "SECRET", and "CONFIDENTIAL." Information is classified only to protect the national security. To have access to classified information, a person must have a security clearance at an appropriate level and a need-to-know. 2 National Security Information National security information is marked to alert recipients about its .
