Olive trees are native to the Mediterranean area, but are grown around the world. There are a variety of reasons to grow olive trees ranging from maintaining orchards to obtain the fruits to even growing them as potted ornamentals. Fruitless olive trees are grown as an ornamental lawn tree and are prized for their silvery green leaves and dense shade. They also are excellent subjects for growing as bonsai.
When to Prune
Pruning is best done after the winter rains are over, but before the tree begins to flower. If you prune too early, the cuts are an opportunity for moisture to enter and cause rot. If you wait too late, the sap is up and the tree doesn’t have time to put out new growth for increase blossom production.
Pruning Young, Healthy Olive Trees
Healthy olive trees need minimal pruning. They can be lightly pruned, starting at around age two years, to encourage bushier growth that has the probability of producing more fruit. Suckers, low growing branches that do not fit with the general growth, can also be trimmed away. Suckers tend to rob the upper branches of nutrients and moisture as they are drawn up from the roots.
Using a sharp, clean set of pruning shears cut the unwanted twigs next to the branch. As you trim, think of the shape of a martini glass. When your tree has this general shape, the center branches and the external ones have better sunlight exposure. This helps to encourage healthy leaves and maximum fruit production.
Best Tools for Pruning
The best tools for pruning any tree are a pair of sharp hand shears, a pair of long-handles loppers, a short, stiff pruning saw, and (for those really big limbs) a chainsaw. For young trees, and for young twigs and small branches, a small pair of hand shears should be sufficient. Make sure they are sharp so that they cut neatly, and that they are super clean so they are not a source of infection for your tree. You can clean them by dipping them for thirty seconds in isopropyl alcohol (sometimes called rubbing alcohol).
Long-handled loppers are your next pruning tool. These are good for slightly larger limbs that cannot be easily cut with the shears. They give you a slightly longer reach without having to use a step-ladder and make the same kind of clean cut as the smaller hand pruning shears.
For limbs that are too large to cut with loppers, but too small to merit bringing out a chainsaw, you can use a hand pruning saw. These are often slightly curved for easy use. For tall branches, you can sometimes use a manual pole saw. Like your shears and loppers, your pruning saw should be sharp and clean.
If you are pruning an older tree that has large dead limbs, you might need to use a chainsaw. If the limbs are not too large, you can use a gasoline or electric pole saw. These resemble a small chainsaw on the end of a pole. Like all chainsaws, they should be used with care.
Finally, if the tree is truly old and has large, dead limbs, you might have to resort to a full-sized chainsaw. Be sure to use a good ladder and appropriate safety equipment. It is also an excellent idea to use the buddy system when using any powered saw, especially when trees are involved.
Pruning Older Trees
Pruning an older tree that has been neglected can be a real challenge. The general principles that you will use are similar to those applied to trimming a young tree. You will want to trim away any suckers that have grown on the lower trunk. Next, you will need to cut out any dead or diseased limbs. Finally, you can focus on gently shaping the tree. You might need to be patient and wait for the tree to put out some new limbs after the damaged limbs have been removed.
Clearing Up Afterward
Once you are finished pruning, it is a good idea to remove the trimmings from the area. This is especially true if the trimming was done to curtail pests. By bagging and removing the trimmings, you help prevent spreading problems.
Potted Olive Trees and Bonsai
Although potted olive trees and bonsai are likely to be protected from the weather, many of the same practices apply when pruning. You might need to prune an olive tree that is being grown in a pot more severely than you might a tree that is being grown out of doors. Even so, your primary purpose in pruning is to shape the tree so that more light can get through to the inner branches. Although a potted plant is unlikely to produce fruit, pruning will often encourage full, leafy growth.