Why should you consider pruning?

• There are several reasons to prune:
• Increase safety
• Improve plant health and fruit quality
• Aesthetics

Safety is not always considered, or at least is not often the first consideration when thinking about pruning, but let’s lead with that discussion anyway.  Well pruned trees tend to be healthier and stronger.  This means that they will not have as many dead branches to shed, they will better resist wind and ice damage, they will harbor fewer pests, and will be composed of predominantly healthy and strong branches.  Stay safe, prune your trees.

As mentioned, pruned trees tend to be healthier, and healthy trees produce higher quality flowers and fruit.  Why are they healthier?  Dead, diseased, and damaged branches are removed, so they don’t host additional pests.  Removing branches also reduces rubbing which damages adjacent branches.  A well pruned tree also maximizes air movement and light penetration for increased health of the foliage and maximum photosynthetic efficiency while also reducing the likelihood of disease occurrence.  When pruning, water sprouts and suckers (Figure 1) are also removed which reduces competition for the available water and nutrients that the desired tree and tissue needs.

Let’s face it, pruning also gives us the opportunity to design our desired aesthetic.  If you’re pruning an apple tree, maybe you like the look of the central leader, perhaps you prefer a vase shape or open center, or even trellised or espalier training (Figure 2).  Pruning gives you the creative permission to design your plants to match your desired look while increasing plant health and improving the safety of your property.

Tools

If you are a tool geek like myself, you can certainly go overboard with bunches of specialty tools, but you don’t necessarily need to.  I’ll list common tools below and highlight those that I consider to be a bare minimum for most pruning jobs.

• Hand pruning shears
• Bypass loppers
• Anvil loppers
• Pruning Saw
• Pole pruner/pole saw
• Hedge shears
• Chainsaw
• Ladder

Hand Pruning Shears

The go to.  Hand pruning shears can be used for pruning small diameter (< 3/4 inch)  branches and are equally as well suited for pruning flowers, garden plants, vines and any other relatively small growth.  Although there are several types of hand pruning shears (bypass, anvil, and ratchet), I’d recommend starting with the most common and clean cutting, which is the bypass pruner.  These act like heavy duty scissors and are pretty universal in what they cut, although they are best suited to small diameter, living tissue.  Anvil and ratchet pruners do a bit better job with dead or woody tissue.  They may have a bit of an uneven cut or slightly crush the stem of living tissue.  If hand or writst strain is a concern of yours, the ratchet pruners can alleviate that concern and would be a great option.

Loppers

For me, loppers get the second most use.  They come in various sizes, but most can handle branches up to two inches in diameter.  They give you the mechanical advantage of leverage, so don’t tend to strain the hand and wrist as much as hand pruners can.  They also extend your reach by quite a bit, reducing the need for ladder work.  If you’re similar to me, you’ll do just about anything to stay off of a ladder for fear of falling.  Just like the hand pruners, you can get these in anvil or ratcheting styles as well.

Pruning Saws

If you’re dealing with especially hard wood, or larger diameter cuts (up to five inches) the pruning saw will be your hand tool of choice.  These are available in many different shapes, sizes, and styles.  If you have an old and unruly tree that needs significant work, then be sure that you have one of these saws handy.

Pole pruners and pole saws

Did I mention that I don’t like being on ladders?  When you need to reach those dead, diseased, or damaged branches or water sprouts that are just beyond the reach of your loppers, grab your pole saw or pole pruner.  The pruner versions are best suited for branches up to or just over an inch thick, while you can tackle larger cuts with pole saws.  You can extend your reach significantly, with most extending at least eight feet and some up to 14 feet.  Pole saws can be manual, battery powered, or gas powered depending on your needs and preferences.  One thing to keep in mind when using these tools is safety…branches fall when you cut them, so be cognizant of where they are falling and be sure that you are wearing the appropriate personal protective equipment.

Hedge shears or hedge trimmers

If you have a hedge or a lot of bushes that need shaping, this is the tool for you.  They are much more efficient than pruners for jobs like that.  They also work great for shaping evergreens and deadheading patches of perennials.  Depending on the shears that you get, you’ll be limited to relatively small diameter (< ¾ inch) stems.  Like several other tools, these can be manual, electric, or powered by fuel.

Chainsaw

Need to drop a tree or do some significant basal pruning?  Do you have many large branches to remove? Want to have your neighbors watching you work?  Get a chainsaw.  If you do go with a chainsaw, please spend ample time learning how to safely operate this piece of equipment, and if you don’t feel comfortable hire a professional arborist for these larger jobs.  The diameter of branch or trunk is only limited by the bar length that you choose to purchase with your saw.

Ladder

I put this tool last, as it is the last tool that I prefer to use. That being said, often it has become a necessity, especially if you have taken over, or have, a mature landscape.  I’ll be on a ladder late this winter as I am trying to reclaim decades-old apple trees on our new property.  Use the ladder to get up in the canopy for pruning work and always have a spotter/holder below if you are able.  Always prioritize safety when using a ladder and avoid the use of a chainsaw while on one.

Tool Maintenance

It is important to maintain all of your tools so that they work as well as they can for as long as possible and so that no diseases are spread between trees.  Wipe down tools between uses and be sure to completely clean up any sap or sticky substances that are left on your tools, as they may gum them up and make them less effective at cutting.  If you suspect that a plant that you have pruned may have a disease, wipe down your tools with rubbing alcohol to sterilize them before moving on to another plant.  You will also want to sharpen your tools periodically to keep them making perfect pruning cuts.

 

How to Cut

• Choose the right tool for the location and diameter of the branch.
• On small branches, cut at an angle about 1/4 inch above a bud.  Ensure the bud is facing the outside of the plant, or in a direction that you want it to grow.

• On larger branches a three cut method (jump cut) should be used to avoid peeling the bark on desired trunk or branch tissue.  The first cut should be an undercut about 25% - 50% up into the branch.  The second cut should be an inch or two farther out on the branch.  Cut down until the branch breaks free.  The third, and final, cut should be all the way through the branch, just outside of the collar.  Be sure to only cut the branch tissue that you want removed.  Leaving the collar intact will expedite the healing process.  There is no need to apply tree paint or wound dressing if pruned correctly.

 

What to Prune

• The starting point here is the ‘three D’s’.  First remove all of the dead, damaged, and diseased branches.
• I tend to remove any suckers next.  These will be growing up from the roots or very low on the trunk.
• Now remove any low branches that will be in the way for regular maintenance activities such as mowing around the tree.
• You can then look for branches that are growing towards the ground and remove them.
• Next, look for limbs that are crossing, touching, growing around one another, or significantly competing for space and prune them out.  This would include a competing leader in some instances.
• Now that you have made space and removed most significant limbs, prune any water sprouts that remain.  These are branches that rapidly grow vertically.
• If you see any branches with a narrow, or steep angle of attachment you can remove them, as they  will be weaker branches than those with a broader angle of attachment.

A few tips to consider:

• Start by removing larger limbs nearest the top of the tree if possible.
• Cuts known as ‘thinning’ cuts are preferred to ‘heading’ cuts.  Thinning cuts remove entire branches at the branch collar, while heading cuts only remove a portion of a branch and encourage vegetative growth below.
• Try to avoid leaving large ‘stubs’ when pruning.
• See Figure 3 below for a visual example.

Season to Prune

Generally speaking, the best time to prune is while the plant is dormant.  I prefer late winter to very early spring before plant growth has began.  This will expose the pruning injury for only a short period of time before growth resumes.  It is also easier at this time of year as there is less foliage and a clearer view of the branch structure.

It is notable that sap flow may be significant in some species following pruning.  This will not harm the plant and should not be of concern, but it will likely be noticeable.  A few species to expect this from include maple, elm, dogwood, and birch.  This can be avoided by pruning in late fall or early winter.

Although dormant season is the general rule of thumb, some species bloom early in the season on last years growth and should be pruned immediately after they finish blooming.  Examples of species to prune after they finish blooming include Apricot, Azalea, Chokecherry, Flowering plum, Forsythia, Lilac, and Magnolia.

Hedges should be pruned twice per year, typically in the spring and again in mid-summer.  Prune hedges back to the desired height and remove about 25% of the thickest and woodiest stems and trunks to invigorate new growth.

Common Pruning Mistakes

• Not wearing the appropriate protective equipment which includes safety glasses, gloves, hard hat, long sleeves, long pants, and closed toe shoes.
• Leaving large ‘stubs’ that take considerable time and energy to heal.
• Not using the three cut (jump cut) method which leads to bark peeling and increases healing time.
• Over use of heading cuts
• Using dull tools
• Excessive pruning during active plant growth
• Topping a tree
• Being in a hurry
• Not cleaning tools
• Not researching pruning best practices for specific plant species
• Not pruning

Definitions of terms related to pruning

 

Anvil loppers – Long handled pruning tool that has a single sharp blade that closes onto a flat, anvil-like surface on the other side of the jaws.

Apical bud – Bud located at the tip of the stem that is responsible for new growth and elongation. Also referred to as terminal bud.

Axil – The angle formed by a branch or leaf and the part of the plant from which it arises.  Axillary buds are located here.

Axillary bud – A bud that grows from the axil of a leaf and may develop into a shoot or flower cluster. 

Bark – The protective layer of a tree’s trunk, branches and roots.  There is inner bark that transfers carbohydrates from the leaves to other plant parts, and the outer bark which protects from injury.

Bracing – This when ropes or cables (or similar items) are used for reducing the chances of a tree’s structure failing.

Branch – A secondary shoot or stem arising from the trunk or leader of a tree.

Branch bark ridge – The raised area of bark in the bark crotch that indicates where the branch and trunk wood meet.

Branch collar – Trunk tissue that forms around the base of a branch between the main stem and the branch.  As a branch decreases in vigor or begins to die the branch collar becomes more pronounced.

Bud – A compact growth on a plant that develops into a leaf, flower, or shoot.

Bypass loppers – Pruning tool that uses two blades in a scissor action to make clean cuts through branches.

Caliper – Refers to the diameter of a tree.

Callus – Tissue formed by the cambium layer around and over a wound.

Candle – Refers to the early spring growth of evergreen shoots before needle expansion.

Cambium layer – Thin layer of tissue found directly beneath the bark that is responsible for growth and protection.

Central Leader or Leader – A dominant upright stem, usually the main trunk.

Chainsaw – A mechanical power-driven cutting tool with teeth set on a chain which moves around the edge of a blade.

Closure – Refers to callus growth completely covering a cut or other tree wound.

Competing leader – A branch or trunk that competes with the tree’s main or central leader for dominance.

Coppicing – A form of pruning that removes canes or branches to just above the soil surface.

Crotch – The angle between two branches or shoots near the point of their union.

Crown – Technically, the juncture of the trunk above the roots, but it is commonly used to refer to the foliage comprising the uppermost branch structure.

Crown cleaning – The selective removal of dead, dying, and diseased wood from the crown.

Crown raising – The removal of lower branches.

Crown reduction – The removal of upper branches when the tree has gotten too tall.

Crown thinning - The selective removal of branches to increase light penetration and air movement in the crown, or canopy, of a tree.

Deadheading – Refers specifically to removing flowers that have bloomed and are now spent.  This can be done by pinching, pulling, pruning, or cutting off those flowers.  This stimulates more blossoms.

Decline – When a tree exhibits signs of a lack of vitality such as reduced leaf size, color, or density.

Dormant – A state of inactivity, or no growth.

Espalier – A tree or shrub that is trained to grow flat against a wall or trellis.

Foliage – Collective term for all plant leaves.

Fruiting wood – Shoots or branches carrying flower buds and having the potential for growing fruit.

Girdling roots – Roots located above or below ground level whose circular growth around the base of the trunk applies pressure to the bark area and restricts the flow of sap.

Hand pruning shears – Hand held garden tool that is used for cutting off plant parts.

Heading cut – Removes part, but not all, of a branch or shoot, stimulating new growth.

Hedge – A fence or boundary formed by closely growing bushes or shrubs.

Hedge shears – A gardening tool used for trimming, cutting, or pruning hedges, bushes, or shrubs.

Hedge trimmers – Similar to hedge shears, but this term is often used when describing powered versions.

Internode – The are between two nodes.

Jump Cut – A jump cut removes heavy branches in three steps avoiding tearing the bark and damaging the plant.  This is also referred to as the three cut method.

Lateral bud – A bud found in the axil or along a branch, but not at the end of a branch.

Limb – Same as a branch.

Lopper – A cutting tool, especially for pruning trees.

Luting – The removal of lower branches for under-clearance.

Node – The area of the stem that is slightly enlarged and gives rise to buds or leaves.

Pinching – Removes new growth near the ends of shoots (apical meristem) while it is still young and succulent.

Pole pruner – A tool used for pruning with the cutting parts on the end of a rod or pole.

Pole saw - A tool used for pruning with the cutting parts on the end of a rod or pole.

Pollarding – Trees cut back to essentially the same point seasonally, resulting in multiple sprouts above the cuts.

Primary scaffold branch – A permanent branch that forms the framework of a tree or shrub.

Pruning – The removal of plant parts, dead or alive, in a careful and systematic manner so as to not damage other plant parts.

Pruning saw – A tool used to trim trees and shrubs that has a sharp serrated blade and a handhold.

Sap flow – The movement of water and other fluids through the roots, stems, and branches of plants.

Secondary scaffold branch – Secondary branches that arise from a primary scaffold branch.

Shoot – Vegetative growth produced from a bud generally during the current growing season.

Spur – A short thick growth producing flowers that may become fruit on apple, pear, and cherry trees.

Stubs or stub cuts – Thinning cuts that are left too long in length.  These stubs prevent proper closure of the pruning cut and often die back, creating a point of entry for decay to migrate into the host stem.

Sucker – A vigorous shoot arising at or below the graft union, may arise from the root system.

Terminal bud – Same as apical bud.

Thinning cut – Removes an entire shoot or branch at the base (its point of origin), which does not stimulate new growth.

Topping – The severe reduction of branches without consideration of the specifications for cutting back.  This is considered to be an undesirable practice.

Trunk – The main woody stem of a tree as distinct from its branches and roots.

Waterspout or water sprout – A vigorous shoot, most often growing vertically, that arises above the graft union.

Witches’ Broom – A profusion of vegetative growth that forms at the point of a pruning cut.