The drought is not over for your trees
Robinson Tree Service · Memphis, TN
The trees that this summer's heat and drought killed will not die this summer. They will leaf out thin in April, or come down in a storm two years from now, and almost nobody will connect it back.
In September, Memphis got 0.64 inches of rain. Not 0.64 inches in a dry week — 0.64 inches for the entire month, all of it on Friday the 11th. Every other day in September was dry.
That is 21 percent of normal, in what turned out to be the hottest September ever recorded here. Six of the first eight days hit 100 degrees. Seven record highs fell or were tied. For the year, the airport is running more than eight and a half inches below average, against records that go back to 1875.
We are telling you this because of what it means for the trees in your yard, and because the damage is on a delay.
Drought kills trees slowly, and out of sight
A tree drinks through fine roots — thin, hair-like things in the top foot or so of soil, out under the edge of the canopy. In a long dry spell a lot of those fine roots simply die. The trunk and the big structural roots are fine. The part that actually takes up water is not.
So the tree comes into fall with less root than it had in May, having spent its stored energy trying to hold a full canopy through 100-degree afternoons. It looks the same from your kitchen window. It is not the same tree.
This is why the bill arrives late. A tree that lost a third of its fine roots to the heat and drought this summer leafs out thin next spring, gets through the year on reserves, and fails in the third year — or in the first real wind. By then nobody remembers the summer.
What to look for in your own yard
- Leaves that colored and dropped early — weeks before the rest of the street. That is a tree shutting down rather than a tree turning.
- Leaves smaller than usual, or brown and crisp around the edges while the middle stays green.
- Dieback starting at the top and the branch tips. Trees abandon their extremities first.
- A thin canopy you can see more sky through than last year.
- Cracked, pulled-away soil at the base, especially on the side opposite any lean.
Newly planted trees and very large old ones are both at high risk, for opposite reasons. A tree planted in the last three years has a root ball the size of a laundry basket and nothing beyond it. A mature oak has an enormous canopy to supply and cannot grow new roots fast enough to keep up.
Water them. Properly, and into the winter.
This is the single most useful thing you can do, and most people do it wrong by watering a little, often, close to the trunk. That wets the surface, encourages shallow rooting and misses the roots that matter.
- Water at the DRIP LINE — the circle on the ground under the outer edge of the branches. That is where the fine roots are. The ground against the trunk is the least useful place to put water.
- Slowly. Water put on fast runs off before it soaks in and the roots never see it. A soaker hose, or an ordinary hose on a trickle, left for an hour or two and then moved. If it is running off across the lawn, it is going on too fast.
- Deeply, and not often. Roughly ten gallons for every inch of trunk thickness, every week or two while it stays dry — not a sprinkle every evening.
- Keep going through the fall. Trees take up water until the ground is properly cold, and going into winter dry is how a drought-weakened tree gets finished off.
- Mulch two to four inches deep out toward the drip line, and keep it off the trunk. It holds moisture in and keeps the ground from drying out as fast.
If you want to know which of your trees came through this summer and which did not, that is what a health check is for — and ours are free. A certified arborist walks the property and tells you plainly: this one is fine, that one needs water and watching, this one needs dealing with before spring.
Where these numbers come from
If this is your situation
Questions about a tree on your property? 901-363-3539, or send us a note. Estimates and preventative check-ups are free.
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