PRUNING: THE MOST IMPORTANT TREATMENT FOR TREES

Pruning is the removal of live or dead branches from standing trees.

It also means to trim (a tree, shrub, or bush) by cutting away dead or overgrown branches or stems.

Most trees require pruning. But remember not all trees need pruning. Some are self-pruned, like eucalyptus species.

Photo credit: independent.ie

WHY PRUNE

1. To improve stem quality( knot-free lumber/bole) Increases its commercial/stumpage values by 20% to 25% 
2. To reduce disease and pathogens
3. To remove parasitic plants e.g. mistletoe
4. To enhance safety( by roadsides & powerlines.)
5. To improve appearance/aesthetic quality
6. To facilitate free air circulation in a tree stand. 
7. To encourage growth and hasten tree maturity

WHEN TO PRUNE

Hardwood/ deciduous/ flowering/broad-leaved/seeds covered/slow-growing e.g teak, mahogany, camphor, oak, rosewood, melia etc: Should be pruned during rainy seasons as their wounds may exude excessive sap or become vulnerable to disease causing insects or pathogens

Photo: courtesy

Softwoods/Conifers/Evergreen/ Needle-like leaves/seeds exposed/fast-grower e.g pine, auracaria, fir, cypress, etc:  Should be pruned during dry seasons as they produce enough resin/sealant that seal the wounds enhancing quick healing.

Did you know:

That despite their names, hardwood isn’t necessarily harder than softwood, and softwood isn’t always softer than hardwood. The difference actually comes down to the type of trees they come from.

Photo credit: Medium.com

Tips to differentiate softwood from hardwood.

Using you thumb nail, dig into the wood and draw a line on the surface. If your nail leaves a mark on the surface, then it is a softwood. If it doesn't, it is hard wood.
Also look out for spores, or small pocket on the surface. If you spot any, it is hardwood.

Photo credit: qoura.com

Point To Note:

While conifer and dead branches may be pruned at any time of year, it is best to prune live branches during their dormancy  or during the cooler, less busy, more insect-free months.

TOOLS USED TO PRUNE

1. Hand or pruning saw
2. Pole saw
3. Secateurs
4. Clippers
5  Loppers/lopping shears
5. Ladder.

Choice of tool depends on the size of the branch.

TIME TO PRUNE

• Every tree species have a specific schedule/planned intervals for pruning.
• Mostly pruning for timber trees start from year one onwards.
• It is best to begin pruning while the tree is young and the branches are small. This will allow the most clear timber to grow on the bole; since knots form as each year's new growth surrounds a branch, living or dead.
• Also, it is easier, more efficient and healthy for the tree to prune small branches regularly than to prune large limbs. 
• Usually the tree should be pruned after it is at least 3 or 4" diameter. 
• One should never remove more than 1/3 of the live crown of the tree. 
• This operation may be repeated regularly until the lower  the right bole height is achieved, in case of lumber/timber.

WHICH TREE TO PRUNE

Newly planted trees: Should not be pruned unless a branch is broken, diseased or dead, because these trees need foliage to produce carbohydrates (sugars) that are then transported to the root system for initiation of new roots.

Young trees: After a young tree is established for one to five years, the tree can be pruned to encourage a well-branched canopy. Lower branches can be removed to raise the canopy, if desired.

NB: Always only  remove no more than 1∕3 of the total crown of a tree at one time. Young trees also need corrective pruning to remove crossing branches, double leaders, watersprouts, and root suckers.

Older trees: Established trees, if properly trained when young, require little pruning.

STEPS OF PRUNING OF OLDER TREES

Before you prune have with you a sharp pruning tool, disinfectant e.g. hydrogen peroxide to clean your tool to avoid spread of diseases from one tree to the other and a ladder for trees higher than 2m

Steps:

1. Walk around the tree to determine the formation of branches
2. Decide on which branches to remove.
   - branches with 1 inch diameter or more should be removed.
   - Root suckers that are a threat should be removed.
3. Make three pruning cuts:
  a) First undercut
  b) Upper cut to remove the branch
  c)  Final cut

Select the branch that you want to remove. On large limbs, the first cut should be 12 to 18 inches from the limb’s point of attachment.
The cut should be made right at the point where the branch meets the stem( branch collar), as shown here below.

The first pruning undercut is made 1∕2 way through the branch.

The second pruning cut should be made on the outside of the first cut (i.e., farther from the trunk). Cut all the way through the limb from the top down, thus removing the weight of the branch.

The final cut is made next to the tree’s trunk outside of the branch collar. Cut from the top down and cut all the way through the remaining branch stub.

Note:

The branch collar should be left intact. DO NOT cut the branch flush with the tree’s trunk. A proper cut avoids large wounds, and allows the tree’s wound to close quickly.

PRUNING STEP FOR MELIA VOLKENSII ( MUKAU)

Melia is one of the strangely fast growing first class hardwood, with a growth rate of  1m/yr and matures after 15-20 years, attaining a height of 6-20 m tall with diameter of up to 25 cm; unlike others that are slow. It is an indigenous tree that is endemic to semi arid and arid areas (ASALS) of Eastern Africa (Ethiopia, Somalia, Kenya and Tanzania), in the family MAHOGANY (Meliaceae). Besides being fast growing and melia produces high quality termite resistant timber in Kenyan drylands , that is, Kitui, Makueni and Machakos Counties.

Source: www.betterglobeforestry.com

Photo credit: Betterglobe media

Objective of planting Melia

• To produce quality timber, post, poles, fodder, bee forage and as an agroforestry tree.

Why prune Mukau

• To obtain a clean quality bole height of 5m, with 10cm DBH by year 4

Photo credit: Betterglobe media

Principles of pruning melia

1. All branches 1inch (2.5 cm)  and above in diameter should be selectively removed.
2. All double leader/ multiple stem should be, assessed and the most vibrant spared as other are removed.
3. All whorls must be removed, but progressively.

When to start pruning.

• From year 1 onward.

Schedule for pruning.

Year 1: No pruning except for double leader and whorls
Year 2: Pruning after rains
Year 3: 2-4 passages
Year 4:  2-4 passages

Melia pruning steps:

1. The three step above are the same here.
2. Remove whorls,( in 2-3 time),  double leader and also cut back poorly formed multiple stems to encourage re-sprouting/ coppicing.
3. Remove branches smaller than 2cm  with secatuers and bigger with pruning saw.
4. Use ladder for trees higher than 2 metres.

It is therefore only prudent that a serious tree farmer must undertake pruning, if any valuable benefit is to be achieved. 

Always seek professional advice and guidance from qualified forest expert or arborist.