They need water but not too much: Here’s how to nurture a young tree during dry times
Consistent moisture is essential when establishing new plants, especially trees. Weather trends over the past few years show that we are destined for feast or famine regarding natural rainfall, and we must rely on routine supplemental watering to help establish our trees.
Proper watering is crucial for root development. It is the critical difference between success and failure during this first year. The goal is to keep the tree evenly moist, avoid additional stress, and know when and how much water to apply. This can take time and effort.
Young trees should be watered deeply by thoroughly soaking the root ball and the surrounding soil. Under typical summer patterns, that should happen about once a week. Watering too frequently can lead to oversaturated soils as the water does not have time to drain. Surprisingly, overwatering kills as many trees as underwatering.
How much water should be applied? A helpful guide is to apply at least 10 gallons of water to the root ball and surrounding few feet that radiate under the tree canopy per week. This places the water around the area of new root development. When applied slowly, 10 gallons allow the water to soak into the soil and reach those deeper roots without runoff.
Check the soil. It should feel moist, not soggy. This amount would be a good start for trees with 1 to 2 inches of trunk diameter. Larger trees will need twice as much.
Creating a low berm a couple of feet out and around the planting hole creates a reservoir that holds the water and allows it to soak in. Other methods can be used to help in watering. A 5-gallon bucket can be used to soak the roots slowly. Drill one or two small holes, 1/8 inch in size, in the side near the bottom of the bucket. Fill the bucket and let it drain. This simple strategy is helpful in knowing how much water is being applied. Move the bucket around the root area to keep all sections of the tree hydrated.
Tree gators or water bags are also available. These are designed to wrap around the trunk or lie flat on the ground. When filled with water, they gradually empty and soak the soil. Applying supplemental water with a bucket or a water bag is recommended for the first year of establishment.
Lawn sprinkler systems may supply enough water to keep the grass green but are ineffective at watering young trees. They do not water deeply enough to soak the tree roots thoroughly. The tree declines and succumbs to drought.
They can also deliver too much water and frequently cause the tree to be overwatered. Indications that a tree has had too much water include wilting and yellowing of the leaves. This is incredibly challenging because the visible symptoms of too much water are similar to not enough water. This leads people to add more water, potentially killing the tree.
The bottom line is that during harsh conditions, don’t rely exclusively on the lawn sprinkler system to water a young tree.
To help your new tree establish, remove the grass around the tree and carefully apply a layer of mulch. Ensure there is no mulch piled up against the trunk. When combined with timely watering, this will help ensure a beautiful tree for the future.
One last tip: Even trees planted two to five years ago will benefit and thrive with an additional drink during more extreme periods of drought.
Dennis Patton is a horticulture agent with Kansas State University Research and Extension. Need help? Contact the Johnson County Extension gardening hotline at 913-715-7050 or email garden.help@jocogov.org.