Oak trees need pruning from time to time for many different reasons, so when is the best time to prune them?
When should oak trees be pruned? During the dormant season in the winter. After leaves have fallen off but before the active growing season. Dead of winter is best when there isn’t sap running yet.
While you can prune trees anytime there are best times and worst times to do it. If you are looking to keep your oak tree as healthy as possible then you will want to paid attention to the seasons. If you happen to prune at the less favorably time you run the risk of killing the tree. I will explain. . .
Is It Too Late To Trim Oak Trees?
This will really depend on when you are asking the question. The reason it is best to prune your oak tree in the winter months is because of a disease that gets spread to live tissue in the summer months.
Oak Wilt is a disease fungus that is spread by insects which are most active from April to the end of October. A contaminated pest can land on your freshly cut oak limb or trunk and that is how the disease is spread.
It can also be spread by the oak’s root system. This disease fungus is very aggressive and can kill the tree!
If at all possible save the majority of pruning for the winter dormant months.
There is always going to be that occasional limb that will need to be trimmed back so you can walk without ducking or maybe a limb has grown to the point that it is rubbing on your house roof or siding.
Keep in mind, if you are just pruning a limb because it is in the way observe the what’s left of the limb to see if the leaves are getting any sunlight. If the whole rest of the limb is very shaded then more than likely the limb will die. You might as well just prune it off at the trunk in that case.
Storm damage is another situation in which you don’t really have a choice in the matter and you just need to take care of pruning the damaged limbs from the storm as soon as possible.
When Should I Prune My Live Oak Tree?
Live oak trees tend to grow more in the warmer climates, so you will have to adjust your timeframe a bit to help avoid the Oak Wilt issue. Just keep in mind to think more about nature. When do insects come out where you live? When does the tree sap start moving?
If you keep this in mind you will naturally be able to know when you are pushing your luck with pruning your live oak tree.
Some experts suggest that if you must prune your live oak during the insect season to use pruning sealer to drop the risk of infection.
In general, studies have shown that pruning sealer actually traps in moisture and can cause rot. You will just have to decide between the two issues.
I would lean towards using the pruning sealer because the worst-case scenario is that you just damage a small area around the cut site; where as oak wilt can kill the whole tree.
You also need to keep in mind if it happens to be a stressful time for the live oak tree. Is it dry and hot? Or is it later in the fall, in which you might be encouraging new growth that will not harden off before the cold winter temperatures?
How Often Should You Trim Oak Trees?
Oak trees in general don’t need to be pruned. Nature made the tree to exist without human intervention.
But if someone has planted an oak tree in a place that it really doesn’t fit that is a different story.
It is always better to cut off less every season than to give it a severe or hard pruning once every decade or so.
How To Trim An Oak Tree Without Killing It
Dead Limbs: With any pruning, including oak trees, you will want to start with any dead limbs or sections first. If you notice dead limb sections prune them off back to a fork in the branch. If the rest of the limb is well shaded you will want to go ahead and cut it off at the trunk since the whole limb will die without sunlight to any of it’s leaves.
Crossed Limbs / Branches: Next look for branches that are rubbing each other or cross each other to where they will be in each other’s way in the future. Prune out the one branch that is missed directed and leave the one that is growth from the trunk outward or that just looks like it is growing the right and keeps the shape you are looking for.
Limbs That Are Too Low: Everyone enjoys walking under majestic trees or simply being able to maintain under them without having to duck or having one’s hat taken off. Prune the limbs off at the tree trunk since limbs do not get higher as the tree grows.
The height of the limb is what it is. As the tree grows it forms new limbs. The existing limbs will always stay at the same level until the limbs get so long that it starts to droop.
When the oak tree is smaller don’t get too carried away with “heading” it up. Only cut 1/3 or less of the branches because it needs the leaves to generate the energy for growing. It is better to take off a few limbs every year as it grows to head up the limbs on the tree.
Bad Crotch or Fork: Limbs that tend to grow with a very acute angle to the trunk cause issues as the tree matures. As the tree grows they will cause deformed growth that if left alone can make the tree susceptible to storm /wind damage and invite rot because it will trap debris and water that will just sit in the pocket.
This can also lead to two leaders. With oak trees you want it to have only one leader, so prune out any competing branches to the leader while it is still small. Once the tree gets to any big size it might take half the tree out if you try to cut out the branch that is competing with the leader.
One trick is to just cut the competing branch back to give the leader more room to take over that position with new growth. But if that branch has a bad crotch it is best to just cut the whole branch off at the trunk.
Percentage of The Total Oak Tree Canopy: With any pruning session you don’t want to cut more than a quarter to a third of the total canopy of the tree. It is always better and less stressful to trim out less each year, then it is to wait for a decade and try to prune out more all at once.
Related Questions:
Pruning An Oak Tree To Keep It Small. First you should try to select a tree that when it is fully grown will fit the space. If you start pruning when the oak tree is small you can prune it to stay small. The trick is to try to keep the overall shape of the tree, just in a smaller version.
You want to prune it so that the bottom branches still get sunlight to the leaves. Think of a cone or triangle shape with the bottom being the widest part. If you cut 2 feet off the top then you will have to also trim the ends of the remaining branches to keep that triangle shape with the leader (top) being the narrowest and highest point.
Can Oak Trees Be Topped? No, oak trees by nature have a leader or lead trunk that all the future limbs come off of. If you top the oak tree other branches will try to grow to take the leaders place.
Now every year you will have to prune all those branches as well.
Topping the tree will not kill it. It will just have a strange unnatural shape and always be trying to grow a new leader. That being said, if you cut all the top off then the stress from that will kill the tree. You can observe this where oaks have been planted under electrical power lines.