How to Water Drought Stressed Trees in Little Rock
Posted by Kathy Wilder on Mon, Aug 16, 2010
You may have noticed some of your trees dropping leaves or maybe the leaves are just brown at this point. Lack of rain and 
100+ temperatures are leaving their mark.
The first trees to be affected are those that love water and those with little leaves. River birch and other birches, cedars, dawn redwoods, cypress trees, etc. are all gasping for water. Even large native trees like oaks are succumbing. A recent UPI article points out that the trees in your yard are at a distinct disadvantage because their root growth is limited to your yard in a way that would not occur in nature.
Another significant detriment to your trees’ health is the fact that we do stuff to our landscape that isn’t really good for our trees. We rake up the leaves which, in the forest, would have rotted and provided natural fertilization. Sometimes we weed-eat around them, damaging the bark at the base. Sometimes we plant trees in our yard that we like, even though they are not native to our area, and not suited to our climate. People even plant them wrong – too shallow or too deep. We’ve even seen trees that were planted with the root ball containment still intact – burlap or nylon or wire.
Many trees are planted much too close to the house – for some reason, people seem to plant beautiful upright Japanese maples in their flowerbeds, right next to their houses. These can get 30’ tall -- where do you think the roots go? (If you want a Japanese maple in the flowerbed, look for a semidwarf or weeping variety.)
And yet another factor to consider is the cold winter we had and 
what kind of freeze damage the trees sustained. Trees react slowly to freeze damage, and it may just now be showing up, in that the mechanisms it possesses to move water and nutrients through itself are not working.
When a tree is not at peak health, it is open to all kinds of misery – insect infestation, diseases, and drought stress.
As the UPI article points out, some are already gone. But, if you have a tree dropping leaves, the only hope for it is lots of water. Watering a tree isn’t anything like watering a lawn. You have to really soak it. You need to get the water down one and a half to two feet into the soil. Use a sprinkler, or just turn your hose on low, put it down under the drip line, and just leave it there. If you notice water running off the lawn, not being absorbed, stop watering until the water is absorbed, and then resume. Rocky, sandy soil will absorb water more quickly than clay soil. Be careful not to put the hose right at the base of the trunk – the roots aren’t there, and watering at the trunk could give you disease problems.
When you have the soil moistened to a 1 ½ - 2 foot depth, then you’re okay to water normally, which means watering deeply, once, twice or 3 times per month, depending on the kind of trees you have. Cypress or birch will need more water, while drought-hardy trees like Chinese pistache or hackberry will need less.
Phytosphere has a more in-depth article on watering trees.
Note: to keep your trees healthy and give them a better chance to withstand drought, winter damage, insects and diseases, be sure to fertilize them! We offer a tree and shrub program that includes both fertilization and insect & disease spraying. If you just want a couple applications, choose the early spring and the fall fertilizations. If you’re a DIY kinda person, fertilize before leaf out in the spring and again in the fall, after the leaves have fallen.
On a final note: does anyone know a rain dance?
This large oak tree in front of our office has heat stress on the left side, possibly because it's even hotter next to the pavement and traffic on that side!