My article about early leaf drop in Silver Birch trees is very popular – but has really peaked this year.
My own trees have started showing a few yellow leaves this time around, and I have concluded that it is due to heat stress as a result of the prolonged warm weather and low rainfall we have experienced. I know that some places had torrential rain a few weeks ago, but that didn’t happen here in Nottingham. We just had a bit of drizzle, and the temperature has remained pretty much in double digits the whole time, and has been in the 20s for the last week or so (almost the 30s the last few days, with another week of the same predicted).
Having looked into it, deep watering is the suggested remedy, and I’m right in the middle of doing that just now.
When trees are stressed as a result of high humidity and low rainfall, they can’t get enough water and begin to shut down just as they do in the Autumn. It doesn’t kill them unless it happens year after a year, but obviously you can take steps to deal with it once you notice it.
I’ll keep this updated over the next month or so with the results of deep watering.
OK. One week since starting deep watering and all the yellow leaves have fallen, with no more turning yellow right now. It’s still very hot, and two more weeks at least of similar weather is predicted.
I’m fairly certain that there’s going to be a hosepipe ban, and that will change the game a little. But we’ll see what happens.
Well, it was definitely that! No yellow leaves at all, now (mid-July), and the tree is fine. The temperature has remained in the mid-20s or higher with no rainfall at all for well over three weeks until last night – but that was nowhere near enough to do anything to the parched ground. The only problem now is the increased humidity, and that looks like persisting for at least 10 more days.
Still no hosepipe ban.