Since the majority of newly planted tree and shrub loss is due to water supply problems, here are a few tips for caring for your new plants to protect your investment and keep them looking good.
Water deeply and slowly. It's important to water deeply and slowly using a hose or drip irrigation system for at least the first year. This encourages the growth of deep roots, which anchor well, make the tree more drought tolerant. If a deep root system has been established over the course of the first two years, your plants will require very little watering in the years to come and are less likely to damage curbs and sidewalks
Sprinklers are for lawns! Most sprinklers are designed to water to a depth of only a few inches. Trees and shrubs require more water, less often than your lawn. When installing an irrigation system, planting beds should be on separate watering zones than your lawn. It is always best, if possible, to re-direct lawn sprinkler heads away from plants and rely only on hand watering or drip irrigation for trees and shrubs (especially for the first 1 to 2 years).
You need to know what type of soil your tree is planted in. If your soil is sandy, irrigate more often with less water; if heavy clay, space watering times farther apart but add more water each time. Clay soils can store twice as much water as sandy soils. Of course, rain must be taken into account. Keep in mind that soil conditions can change in as little as a few feet, so conduct spot drainage tests beforehand.
Frequent over-watering can be as serious as under-watering! Generally, For a tree planted in spring, hand water the root ball twice a week for the first month, and then widen the watering basin to include the whole planting area, and water weekly for the next two months. Decrease to every two weeks, sticking to that schedule until fall. Water every four to eight weeks through the second and third years after planting. This can vary depending on your soil’s moisture retention and drainage; all watering guides are just guides, not rules!
Be sure to keep a grass-free area around trees and shrubs. It is advisable to keep a radius of at least a foot–more if possible–around the tree or shrub. Grass is tough competition for young plants, and they will recover from transplant shock much more quickly if their competition is reduced. This grass-free strip can be left bare, or even better, covered with mulch. The mulch will keep the root area cool and moist.
Limit pruning at first. During the first year after planting, pruning should be limited, unless necessary, to removing broken, diseased, or poorly-positioned branches. The plant’s expanding terminal buds, which release a chemical that initiates root growth, triggers the spring root growth of many species. If these buds are removed, root growth may be delayed.
Give plants time to recover before fertilizing. Plants have to recover from transplant shock before fertilizers are useful. A slow-release starter fertilizer specifically made for newly transplanted trees and shrubs, when applied at time of transplant, can greatly reduce the time needed to become established. No other fertilizers should be used for the first year after transplant. After the plants are established, Liquid fertilizers should be avoided. Dry, slow-release fertilizers are best for established trees and shrubs.
Follow these tips and you will enjoy your new plants for years to come.