Q: I was under the impression that the best way to water large, older trees was with a watering spike, stuck one or two feet into the ground. I bought one and have been trying to save all my precious oaks and maples from the drought. Now I read that this “isn’t a good idea” in a Home & Garden Fact on August 22. What’s the scoop?
A: The fact is correct; most tree roots grow within a foot of the soil surface. Putting water below them does them no good. You can use a lawn sprinkler to irrigate where there are several trees near each other or a soaker hose where there is a single tree. The soaker hose should be laid under the ends of the tree branches because that is where the absorber roots are most numerous.
The minimum you should apply is fifteen gallons of water per inch of trunk thickness per week. If you have several trees in an area, use a lawn sprinkler to irrigate until you’ve applied three-fourths of an inch of water, as measured by a few of tuna cans scattered in the area.