In another post we discussed the most important action to take when caring for older trees. I think it might be of interest to go into the details of extending the biological life of fruit trees, for example. apple trees.
This situation regarded 40 neglected trees, now aged 70 years old. Over a 3-year period, they have been brought back to a satisfactory shape and condition. The most important thing is that the foliage is now completely open to full sunlight again. Here is how was this done.
Those trees had been left to their own devices. They were on the grubbing list. There was very little canker or any other serious diseases in the trees’ basic framework. Apart from too many woolly aphids, there were no major problems with the insect population. That meant that there was a good level of predators for the various insects present in those trees. The bark of the trees’ trunks looked very healthy. In fact, that’s where the woolly aphids over winter. For that reason winter wash, to the point of run-off, will be essential as a routine treatment to stop woolly aphids getting out of control.
Finally, as a basic health check, the foliage, that is the leaves of the canopy, looked fine. New shoot growth was sufficiently vigorous to renovate the older cropping wood, as well as providing enough leaves to feed a reasonable crop of fruit.
So now after this health check, I had to decide how to prune the tree, an operation to be performed during the winter months to start off with. Is the tree capable of feeding its current structure, or are the lower branches beginning to lose vigour? Or, to put it another way, is the current structure too large for the tree to maintain? Then I had to decide how many basic framework branches there were, and reduce the number of main tree structure branches to 4 or 5. As they were central leader trees, that substantial vertical branch, the leader, had to stay. If they had originally been set up as open-centre trees, then it would have been best to renew that type of structure.
When trees get older, often but not always, the top branches last the longest while the lower branches gradually lose vigour and finally die out. The skill therefore is to assess which branches are most suitable to form part of the re-vitalised basic framework. As a result, some very substantial saw cuts will have to be made. To stop major infections occurring, these big saw cuts will need to be sealed properly with a specially-formulated wood sealing compound.
The next point was to establish the state of health of the smaller-diameter limbs, which form the outer layers of the tree canopy. In neglected fruit trees, most of the time there are far too many of these and therefore these branches will need to be reduced in numbers. This is essential as each branch of the tree canopy has to receive direct sunlight, so that the leaves can perform photosynthesis which provides energy for the tree.