What is pruning and why do it?
Pruning is very useful for strengthening the health of fruit trees and ornamental plants in your garden. In addition to facilitating the natural regeneration of plant tissue, it helps to preserve the trunk and foliage from diseases and potential attack from parasites.
When to prune
There is no period that is more or less suitable for pruning plants. The ideal time varies greatly, depending on the type of tree and the result you want to achieve. In some cases, you may have to prune the same plant several times a year and for different reasons. On average, however, most pruning needs to be done between autumn and spring: during the plant’s vegetative rest period.
The moon plays a fundamental role in pruning, as it does with grafting and sowing: trees pruned on days when the moon is waning produce an increasing number of fruits. So before starting to cut, check the lunar calendar for agriculture and make sure that the period you have chosen is actually the right one.
The tools of the trade
To prune trees and plants in your garden, you can use either manual tools, or tools powered by electricity or a petrol engine.
Manual tools are fine for small jobs on trees and plants of limited size, whereas electric or petrol-driven tools are indispensable for extended areas or high-intensity jobs. To cut small/medium diameter branches or small hedges, you can use a simple pair of pruning shears or a pruner, and then finish the details with secateurs. However, for very large garden hedges or multiple fruit trees, you should use a hedgetrimmer or a telescopic pruner like the PPX 271, which extends so that you can reach the highest branches without using steps or platforms.
Pruning chainsaws, which are available with different displacements and guide bar lengths, are the most useful and versatile machines because they are easy to move around among vegetation when working on small and medium-sized branches, allowing fast and agile manoeuvring for maximum efficiency.
Before proceeding with cutting operations, always make sure you have suitable personal protective equipment for carrying out the work in complete safety. You should wear anti-cut protection jackets and trousers, a protective helmet, protective eyewear, hearing defenders, boots and a safety harness, which will protect your back if you are using a hedgetrimmer or chainsaw with a telescopic rod.
Arm yourself with a blower and a rake too: they will help you to collect plant waste produced during pruning and dispose of it more easily.
How to prune
The basic rule of thumb is simple: the more vigorous a plant is, the less it needs pruning.
That is why old trees tend to be pruned intensely, whereas a light trim is sufficient for young trees and those that are fully fruiting.
Vigorous branches and weak branches
Trees vary, and so do branches on the same tree.
For example, fruit trees have vigorous branches and weak branches, which require different amounts of pruning. How do you recognise them? Vigorous branches extend vertically and the sap inside them flows faster, whereas weaker branches are horizontal and curved.
Vigorous branches don’t bear fruit but are perfect for firewood, whereas weaker branches produce lots of fruits but don’t burn well, being thinner.
To get the right balance between growth and load on the plant during the fruiting stage, you will therefore need to shorten vigorous branches more and weak branches less. While doing so, try to keep the proportions of the plant unchanged. All branches—especially load-bearing ones—must diminish towards the tip. This means that you should cut basal branches less, compared with branches at the apex of the plant.
Just like branches, buds also differ in type and purpose.
Apical buds are the most vigorous, grow at the top of the tree and ensure continuity in the growth of the branch or limb. By contrast, lateral buds form at the axil of the leaf, grow on underlying branches and sprout only when the apical buds are removed.
Regardless of where they grow, all buds can generate leaves and other branches (wood buds), or flowers and fruits (flower buds). In many plants such as apple trees, the buds are mixed and can become both branches and leaves, as well as flowers and fruits.
So, when you prune, always keep in mind the result you want to achieve: if you shorten a branch and leave few buds (flower species), your branches will be very vigorous but will produce less fruit. On the other hand, if you leave lots of buds, you will have plenty of fruit but weak branches. In any case, never forget to leave at least one wood bud on the tree: if you remove them all, you run the risk that the plant will stop growing.
Cut at least 6-7 mm above the bud and at a 45° angle.
Hold the cutting device pointing downward and away from the bud.
If you want the vegetation to grow towards the right, cut the branch above a bud on the right; if you would prefer it to grow towards the left, prune a bud on the left.
Always remember to take into account the species of tree in front of you: not all plants bear fruit on the same branches and at the same time. Some produce fruit on this year’s branches, whereas others only bear fruit on branches from the previous year, or on older branches, or on branches of different ages.
Types of pruning
As already mentioned, not all pruning is the same. So, let's take a look at the most frequent jobs and what purpose they serve.
Green pruning is a type of cutting performed between spring and summer and which is used to remove excess vegetation from very lush plants. It is very useful for thinning out fruiting peach trees or grapevines, for example.
Formative pruning gives young trees a precise shape and ensures their regular development. It is often used to correct branches with bifurcations or to ensure continuity between lower and upper branches.
Maintenance pruning consists of removing dried-up and slow-growing branches from old trees to facilitate the germination of fertile branches. Maintenance is also commonly applied to herbaceous plants used for decorative purposes.
Topping or forced pruning involves entirely removing a tree’s foliage or larger branches to prevent the risk of damage to urban infrastructure. It is a very invasive practice, which exposes trees to diseases and weakening. Nowadays, it is nearly always replaced by less aggressive and more eco-friendly techniques.
Rejuvenation pruning is the removal of dried-up branches from mature or old fruit trees in order to reinvigorate the foliage. If done correctly, this operation is extremely efficient. Just be careful not to cut secondary branches, otherwise you risk damaging the tree irreparably.
When plants or trees grow suddenly and excessively, they can be kept in check with containment pruning. This technique involves cutting only the bulkiest branches while trying to keep others healthy. It is often used for tending hedges.
Pollarding is a cutting practice that involves removing shoots from the crown of a tree in order to facilitate lateral growth.