Farmers and ranchers who care about their trees and windbreaks are concerned about high temperatures and drought conditions gripping much of the Plains and other parts of the country. They know that trees are stressed. Combined with wildfires across the Southern Plains, it has been a tough year for the farmstead forest.
Late August and into September is the period when landowners should consider watering trees to prepare them for winter if drought conditions continue. "It is a common belief that you should wait until right before freezing to water trees for winter survival, but late summer and early fall is really the best time to water," says John Ball, a South Dakota State University Extension forestry specialist. "You might continue to water into October if it remains dry. And in Nebraska and even the Black Hills regions, for instance, winter watering might occasionally be necessary."
Established trees aren't as big of a concern. They may still benefit from weekly watering if drought remains severe. In 2012, when rain was almost unheard of in much of the country and temperatures soared to record highs, even established trees like Eastern red cedar on decent sites in my neck of the woods became victims of heat and extreme drought stress.
Ball says that a small windbreak tree that has been planted within the last year or two still needs about 2 to 3 gallons of water per week during the summer. A 2-inch diameter tree needs about 20 gallons per week during drought, according to Ball. But the water shouldn't be applied all at once. A soaker hose near the tree will provide water in a way the tree can use it. Ball also suggests that the critical watering zone for each tree is about two-thirds the tree's height.
Newly seeded trees are the ones that need the most care during drought. They do not have well-developed root systems, so they require extra attention that first year through the spring and summer. Ball says that a newly planted tree needs a pint to a quart of water each day. A newly planted ornamental tree that is already 6 to 8 feet tall will need about 2 to 3 gallons per day. It is ideal to water the trees daily for the first couple of weeks after planting, because this allows the underdeveloped roots to take in water directly, without fear that some of the moisture will flow away from the small tree roots.
Once it starts raining again, the watering can subside. You don't want to overwater trees beyond their ability to utilize the moisture, because it is a waste of time and resources and it can contribute to root decline due to a lack of oxygen. At this point, however, this is the least worry for farmers and ranchers in the heaviest drought regions.