pruning

Olive Pruning

This is not meant to be the definitive guide to olive pruning, just something that I've thrown together for the net while waiting for that guide to be written. But, as a starting point, it is probably useful to look at where fruit development actually occurs, and what then happens.

The tree in the photo above shows many shoots that have arisen from a branch that is probably 2 years old. It is likely that these shoots were only buds on a wispy shoot 12 months ago. In spring, the buds start to swell and the stem cells in the branch thicken. During the summer, some length is added to the shot buds and during autumn will really start to lengthen. It is on these kinds of shoots that this springs flowers will be carried. That is ,1 year old shoots

The fruit on the shoot above is an example of very good fruit set, and shows that the tree has used most of the sites available to it on the shoot to form fruit. It can be seen that the tip is not elongated. This is possibly comparable to an ear of corn that fills out all the way down the ear right down to the tip

From the photo above it can be seen that in the formation of the shoot, I had fruit buds, and leaf buds. These leaf buds while dormant at the moment will probably shoot over the next month and if not this spring then next spring provide sites for fruit set again. As I understand it leaf buds can become fruit buds, but fruit buds are fruit buds forever. It is quite possible that this shoot will end up looking like the branch in the first photo.

At this point I hope that it is obvious that the soft growth that is at the outside of an olive tree is very important as this is the kind of growth that fruit will form on in the coming spring. When looking at removing wood from a tree, then this is the last kind of wood to remove. (more lower down) In the photo above the outside of the tree can be seen as being quite thick. As this tree has not been pruned much this will be thinned out over winter well before spring to reduce the chance of damaging the fruit buds that will be left on the shoots.

While this tree is young (actually, this is one of my old tree's that has been grafted onto, so its actually about70 years old) This was a very thick shrub.

In the back of anyone trying to prune olives mind should be the fact that an olive tree is a very vigorous shrub. Left to its own devices it will form a thick, dense, mushroom shaped shrub approximately 4 meters high, with branches extending down to the ground.

Consequently pruning/shaping is a regular bit of husbandry. (At this point I should say that there is a school of thought that says that left to its own devices the tree will grow best and provide the best crop, and should not be pruned, I don't subscribe to this school but it should be mentioned.)

The common pruning things to look for in pruning roses carry over to olive trees quite readily. That is dead wood, diseased wood, crossing over wood, and branches pointing in the wrong direction.

Dead & diseased wood should as much as possible always be removed. Crossing over wood occurs when a shoot goes of in an advantageous direction when small, possibly chasing sunlight. This if not picked up becomes a menace and makes it difficult to pick fruit. For this reason, as much as possible the aim of pruning young trees is to establish a framework of branches that in time will become the major branches from which the minor branches and shoots arise. In Australia at the moment the reigning theology is to allow for future mechanical harvesting by encouraging a single shoot for the first 1.2 meters and then allow the branching out from this point. Traditionally the branching out will consist of about 3 or 5 branches.

Just as a bit of a sideline it is probably worth remembering that the olive tree is a factory for the production of olives. Its chief fuel is sunlight. For that reason many people prune to an open center to allow sunlight in the middle of the tree. One of the problems of working in any factory is lack of air. For that reason the amount of branches is often reduced to allow the movement of air into and through the tree. Another problem is the movement of produced goods out of the factory. Again this must be considered in the desired framework that is being encouraged in the tree. It is silly to allow the tree to grow to a height that means that a lot of the fruit is inaccessible. Current theology would say if you have to use a ladder to pick, you?re wasting too much time. However in countries with lower wages than Australia this may not apply. Again, there is little point in encouraging a very thick dense growth of olives that cant be picked because there is no way to actually get to them. Try and keep clear picking paths in mind as you establish the framework. Encourage accessibility at the base of the tree by "pruning up" low branches. I believe that this paragraph was inspired by Michael Burr, whose book on olive growing is superb

Another thing to keep in mind is the direction and strength of the prevailing wind. Branches that point into the prevailing wind are very valuable. Very carefully consider removing them as they may represent many years of investment by the tree in getting the branch to be there.
To use the factory metaphor again, the tree has put a lot of effort into establishing a branch in that area to produce for you. Branches growing away from the prevailing wind are much cheaper, a bad removal may not be noticed within 1 year.
This bit is written a few more years down the track. I think that light pruning can be done after fruit set. If foliage has developed that is blocking access to pickable fruit then remove the foliage if its not carrying much fruit.Sooner rather than later. This will aid in air movement as well. As the fruit bud start to develop for the next spring during the present spring then early removal is not a bad thing.If the tree gets to big then the easiest quick prune is to remove the centre. This allows light and air back into the middle, and helps to keep the shape I think is conducive to easy picking.
Shape your hand like you are going to catch a tennis ball then look at it with the finger spointing up. How your fingers are aligned is a good shape for an olive tree ( in my mind anyway). That is, with 5 branches open in the middle and evenly distributed. When selecting branches to form your framework, pick the best that point in the direction you want. If they are fantastic branches but are only a short distance away from a branch going in exactly the same direction then 1 or the other has to go.
Olives are extremely vigourous. Recovery from a bad prune is possibly 2 years, and will return fruit. After the heavy branch removal at Urrbrae we picked far more fruit. This is normal in circumstances where trees haven't been pruned for ages.

Please remember however that in pruning an olive tree, professionals allow only a few minutes to prune a tree. The aim is pruning, not topiary

A long time ago I was told that it is better to badly prune than to not prune at all. I believe that to be the case. At least by trying, lessons can be learnt, by not trying , nothing can be learnt.

I've just spent a couple of nights updating this site and realised that I hadn't put in a link to what I think is a really good olive producer discussion web site.

If you are interested, have a look here.
Its a message board, but the people are very knowledgeable