One good rule of thumb is to immediately irrigate a newly-planted tree with 2 to 3 gallons of water per inch of its trunk diameter. So a tree whose trunk is 2 inches in diameter when you plant it should be given 4 to 6 gallons of water right away. A newly-planted tree's roots only extend as far as the rootball.

The term “established” refers to the point at which a newly planted tree, shrub, accent, or ground cover begins to produce new growth. New growth appears as fresh foliage or new stems. Typically, the root system of a shrub will be well established after one year. A tree will be well established after three years.

To perform the scratch test, use your fingernail or a small knife to gently scratch a small section of the bark on the trunk or a branch. If you reveal green, moist tissue underneath, the tree is alive. Conversely, if you see brown, dry tissue, it might indicate a dead tree.

The best way to check soil moisture is sticking a finger into the soil about 6” below the surface. After two weeks, water 2-3 times a week until dormant season (when deciduous trees lose their leaves). Continue watering 2-3 times during the growing season for 3-5 years, or until the tree is properly established.