Have you noticed yellow leaves on your fruit tree?
They’re one of the typical autumn features you can expect to see in your fruit trees.
Autumn is usually a pleasant time of cool, crisp mornings. After the heat of summer, there’s a definite shift in the air, and you might even be lucky enough to enjoy some rain. (Though with the increasing variability of the seasons, summer equals too much rain for some people!).
It’s also not unusual to see fruit tree leaves start to turn yellow even when it still feels quite summery. For example, it often begins to happen on a tree that’s been fully harvested.
The typical pattern is that the leaves stay green and keep doing their job while the tree still has fruit on it. Once the fruit has been picked, the tree will rapidly start to go into “senescence”, or winter dormancy.
At that time, the tree starts to withdraw all the nutrients from the leaves back into the buds and bark. The first sign of this happening is the leaves changing colour. This type of yellowing is completely normal, and you see it every year.
Yellow leaves can be a sign of lack of water
Another reason for yellowing leaves (and of more concern) is lack of water. You can see the classic symptoms on this cherry tree.
It’s all too easy for this to happen when you have an automatic irrigation system. Drippers can easily block up, and unless you’re checking them regularly (which is a really good idea), you might not realise you have a problem.
But don’t worry, the tree will start telling you loud and clear. The leaves will turn unseasonally yellow. The dead giveaway is that the leaves on all the other trees nearby are still green.
Is it too late to fix it once the leaves have turned yellow?
Another common reason for leaves to turn yellow is from nutritional deficiencies.
A number of nutritional deficiencies can cause yellow leaves as one of their symptoms, including iron (as you can see above), manganese and zinc.
Fruit tree diseases that can cause yellow leaves
The fourth reason for yellow leaves is because of a virus disease, such as apple mosaic virus as you can see in this leaf.
Viral diseases are not good news, but unfortunately are not really treatable, so the best bet is to look after the tree as well as you can, and try to avoid the virus spreading by not planting other trees of the same type nearby. This is one of the best fruit tree virus databases we know of.
So if the leaves on your fruit tree are turning yellow it’s probably a perfectly normal seasonal response, but your tree might also be trying to tell you something! If you feel like you need more detailed help diagnosing what your fruit tree is trying to tell you, please download a copy of Keep Your Fruit Trees Free From Disease short course.