In several instances, a new owner, etc. will come to possess a new orchard which has older trees on it, and sometimes those trees have not been pruned for some time. Here are some helpful tips as to what to do. First see what kind of variety of fruit tree you have and then notice how it bears the fruits on the branches. I’d recommend cutting out all dead wood first, then see what you have as far as structure is concerned with each individual tree. If the tree is very tall, consider bringing the height down to a lower level by cutting back very long, tall branches to nicely places side branches which are lower down to the ground.
Basic safety issues to be aware of should now be practised. Use an orchard type ladder. It is specifically designed to get into the canopy of the tree and being of a tripod design with three footings touching the ground, is safer than a four footed ladder with four points that touch ground. Check to see that the ground is firm before you climb high.
You will need good pruning tools that feel comfortable in your hands. Quality hand pruning shears, loppers, and hand saw are all basic necessities. A longer reach pruner and/or pole saw/pruner may come in handy as well. These allow longer reach without extending too far off center of the ladder. Never climb to the top rung of any ladder. It is unsafe. If you must lean, do a very little to each side the higher you go and not at all when you are near the high point. Just get down and move the ladder again.
Now back to the tree. If there are sucker growths, they probably will need to be removed since that is likely to be rootstock and not the desired grafted/budded variety. You will need to recognize the main trunk and if you can detect the old graft scar, then you have found the original tree. (this is only needed if there are many sucker growths from the roots). Cut away all suckers and leave the main trunk clean. Now move up the trunk and see if there are any diseased branches or holes in the main trunk(borer damage). If so, treat with appropriate insecticide, following label directions. You want to locate the main scaffold branches and remove sucker growth or watersprouts (sappy vigorous shoots arising from the main branches or trunk). You can keep a watersprout or two if you need a new main branch, just make sure you spread that branch so that it will not develop a narrow crotch. *(wide angle branch crotches are strong, narrow ones are not)
Begin to prune excess growths away from the trunk and main branches to allow light and air. As you progress outward on the main branches, you will want to see that secondary branching is well spaced and gets good light and air circulation around it so that any fruit bearing wood in that area will be healthy with sunlight on the leaves. (if too shaded, then consider cutting off the heavily shaded branch, or cutting back top growth above it.)
Continue to follow branching out to the edge of the tree canopy. If you have an apple, apricot, cherry, pear, it is likely you have many stubby short branches all along the main branches. Do not cut these off arbitrarily. They are the main fruit bearing branches known as fruit spurs. Much fruit comes on these branches for many years, so you want to conserve them and only prune them if too densely branched or to close to each other so that not enought light and air can fall on all the individual small spur branches. You may also consider the direction on the branch that the spurs take, recognizing that the fruit weight can be heavy before harvest and that fruit on these spurs will bend them down until fruit is picked.
The basic pruning idea is to let in light and air to all the branches so that sunshine can sweeten and flavor the fruit for harvest.
You may also consider leaf coverage to help shade the bark and fruit on the outside of the canopy from sunburn.
Fast growers like nectarines and peaches, plums, pluots, and apricots produce less spur growths, and these tend not to live nearly as long as those on apples, cherries, pears.
So pruning on these consists also of cutting the bearing branches back after they have reached the end of their productive time and begin to get too long. You select another branch to take over the older one you are pruning off or back.
Make all cuts cleanly with sharp tools. As a rule, cut above a branch or bud at about a 45 degree angle with the growing branch/bud opposite the high end of the cut.
You may need to prune off quite a bit of growth if the trees have been neglected. Do less pruning on pears since they do not like it and will be more suceptible to fireblight if they produce soft sappy growth from all the regenerative pruning.
You can also prune in stages, ie. over the course of dormant season and summer semidormant season., or also over a period of years.
The well pruned orchard tree is open to sunlight and air circulation. My preference is to keep the canopy low. (I recommend no ladders and prune very severely to keep growth of the tree as low as possible.) .. I will discuss this technique in a later discussion.
Remove all prunings, care being taken to observe that there are no insect infestations. (you’ll need to spray if they are present, or you have seen them previously)
Good sanitation is the rule of thumb here, better to keep things clean and thus avoid insect, disease infestations and the resulting treatments. Clean up all fallen fruits, and dispose of fallen leaves as well. (they can be composted if they have fallen and either added to a compost heap or buried into the ground to decompose and release their nutrients back into the orchard growing area)
The main goal in pruning old trees is to open up a dense canopy, bring the branching level back down to more manageable height if trees have been allowed to grow too tall, necessitating use of tall orchard ladders. Removing any dead, diseased growth, and also any growth that is too dense. Conservint fruiting wood (fruit spurs) .
The following growing season will often see much vegetative growth and you can rub out sucker shoots, watersprouts on trunks, main branches, or just pinck/prune them to become spurs later on. Steady attention to any errant growth and pruning to guide the plant can be done anytime, and if done during growth periods, that cut will begin to heal over immediately.
A good follow up with regular watering as needed, and a fertilizer application or use of mulch, compost will benefit the old trees greatly and help them to bear a nice crop after pruning is completed.
Do not be afraid of pruning, but do look at it with an eye toward how and why you are pruning. All pruning is done for a reason. Shaping, controlling height, length, opening up too dense growth, allowing air circulation, etc. Do not cut to stumps if possible since that can often just die and be an entry for disease and insects later on. Remember that trees are very forgiving and those cuts will become hidden as new growth begins and replaces it.