Just when you thought you'd outwitted the pests that enjoy the fruits from our trees as much as we do, there's another equally crippling disease coming through.
In hot and humid weather, especially if your trees are full of fruit, brown rot can invade and make a mess of a lot of your stone fruit.
It spreads quickly as the spores on the fruit move from one fruit to another, take their hold and multiply very quickly. The spores may have been laying dormant on the bark of the tree, just waiting for the right conditions to spring into action. Fruit hanging + humid weather = brown rot.
So it's time for you to spring into action immediately and go and check your stone fruit trees carefully.
I have just come in from a very thorough clean up of my plum tree. It is laden with fruit but a lot of them had dropped after the freak hail storm last week and were rotting away under the tree (= source of food for brown rot). Of course, this hail storm coming just before Christmas meant that I didn't get out there to clear up. Today I also found a lot of the plums hanging on the tree were affected.
The trouble is with leaving them hanging is that any fruit the mouldy ones touch will also be infected, as well as any nearby fruit because of the efficiency with which these spores move around. A bird landing on the tree might not only peck at the fruit but the shaking of the branches will spread the spores to nearby fruit.
There was only one thing to do and it was to rake up every little last fruit that had dropped, not an easy feat as the branches are laden and low to the ground. But I did it and was rewarded for my efforts as I found other bits and pieces left under the tree which I couldn't see for the grasses growing underneath. (I did a clean up of those too).
And then, it's having a very careful look at all of the fruit and removing the affected plums. I had a small bucket into which the mouldy fruit went straight in and I did try to put them in gently so that no more mould would fly off. None of this debris went into my compost system, needless to say.
This is what we call good plant hygiene.
There may be sprays that could be used but I certainly don't use them while the tree has fruit. Next winter I will give the tree and all its branches, twigs and twiglets a good once over with a copper based fungicide.
Now whatever you do, wash your hands really well before you go touching any other plant!