We just had 2 days of 90+ degree weather here in SF - most of my trees went through it fine but a few are having some leaf burn and dieback - I stopped fertilizing or working trees this week due to the heat; how soon should I restart those activities? Or should I wait until the trees seem to be actively growing again? If it matters, species are pine, yew, maples, and redwood
I have been told if it is going to be 90 degrees or higher at all during the week don’t work on or fertilize for maples. Also have heard once that high summer hits (90+) stop fertilizing maples all together till fall. I keep my maples under over head and westward facing shade cloth(70%) when summer hits. Growing zone 8B costal NC.
Waiting until you see new growth is always a safe approach. This can be tricky as some trees were finishing up their new growth for the season when the heat came.
If the damage is significant, I’d wait before fertilizing or wiring trees. The most important thing is to pay attention to the tree’s water needs. If they remain the same as they were before the heat, the trees are likely in good shape. If the trees stop taking up water, I’d hold off on any work until there are signs of foliage or root growth.