The Kwanzan and Yoshino cherry trees are best known as the Japanese flowering cherry trees that are planted in Washington D.C.--a gift from the Japanese government. They flower each spring and are celebrated at D.C.'s annual Cherry Blossom Festival. The Kwanzan cherry tree (Prunus serrulata) is adorned with double pink flowers and typically has a limited lifespan of only 15 to 25 years. To achieve the most life expectancy as possible, you must take proper care of it, which includes regular waterings during the growing season.
Water your Kwanzan cherry tree deeply after you first plant it. Water it slowly around the entire root ball and once the water begins to puddle, stop. Then wait 5 minutes and water it again until it begins to puddle.
Supplement rainfall, especially during the first year. When the soil dries to a depth of 2 inches, water your Kwanzan cherry tree deeply as described in Step 1. If you have a drip irrigation system, set it to water your tree for one to two hours. The goal is to get the soil moist to a depth of about 12 inches. Water under the entire canopy of the tree. Remember the roots are also growing outward after planting.
Water after you fertilize the tree, which for Kwanzan cherry trees, is ideally done at least once a year in the spring, but can be reapplied in the late spring and early fall as well (with 1 lb of 10-10-10 fertilizer per 100 square feet).