A lot of us are in drought this year and have shade trees. Some have been through severe droughts in the past.
I wanted to open up a general thread to share and discuss meaningful drought information and strategies for keeping shade trees in good health during extended droughts.
Water seems to be the primary care needed to keeps the trees from being overly stressed and susceptible to pests and disease, but the volumes can be staggering for mature trees, and in a time when water supplies are short and most restricted. Additionally, information about how much to water to apply, how frequently to apply water, and specifically where to apply the water varies significantly in public resources, and few take soils into account.
I’ll go first. I’ve been looking at a lot of information, but also a lot of conflicting information. A few things that are not clear to me is (possibly by species), which water target to aim for, specifically where to apply the water, and how much you can skimp and still keep the trees out of poor health a year or two down the road.
There is a PDF attached at the bottom of the page that gives additional information in the free eBook. Calculating the water needs for just the most important 1/2 of my 35 mature trees by the transpiration method she suggests, the trees would need to receive 26,000 gallons in July, alone. Of course that is for optimal health. Most common resources say to water the same amount per month with the guideline of 10 gallons/inch diameter 2x/month (that would be 12,000 gallons/mo). However, some resources suggest that rule of thumb is just for smaller trees. And, of course the rule of thumb doesn’t take species, soil, etc into account.
Seems more complicate than meets the eye, especially given some trees may not show stress for a year or two, before a rapid downhill slide.