07/20/2012
Tree Watering Tips
Homeowners are urged to continue watering trees and shrubs due to continued dry soil conditions and a rain shortage. It is important to know that trees and shrubs will benefit from continued watering – even trees and shrubs that have lacked sufficient watering throughout the summer. Here are some drought-readiness tips from the Morton Arboretum:
• Focus watering efforts on trees and shrubs – not grass. Grass goes dormant and will turn green again when water is available. Trees can die without water.
• Depending on air temperatures, trees and shrubs need at least 1 inch of water applied ever week to 10 days to cope with lack of rain. Larger, established trees have a wide-spreading root system and need not be watered as frequently, perhaps every 2 to 3 weeks. Let the top few inches of soil dry out between waterings to avoid saturation and to allow roots and soil organisms to breathe.
• Water slowly and deeply so water percolates down into the soil, electing one or two deep waterings as opposed to several light ones.
• Use soaker hoses and drip irrigation – effective watering tools because they discharge even streams of slow, trickling water directly to the root zone beneath trees and shrubs. When combined with a 3 or 4-inch layer of organic mulch, plants can use nearly all of the water that’s provided with little evaporation loss.
• When watering small trees, let a hose run slowly at its base until the ground is moist. For large trees, let the hose run at various points around the tree’s drip line – the imaginary line on the ground that encircles a tree’s extended branches.
• Water shrubs at the plant base and under the spread of branches until soil is moistened to a depth of 6 to 8 inches.
• When using a sprinkler system, place a container nearby to measure when you have distributed 1 inch of water to the soil.
• Prioritize watering, caring for newly transplanted trees and shrubs first, then those that have been in the ground from 2 to 5 years and have under-developed root systems. Next, water “specimen” trees or important trees, then all the other plants.
• Water strategically. Plants absorb more water in the early morning, before the warming sun can cause evaporation.
• Avoid using fertilizer during drought conditions. Fertilizer salts can cause root injury when soil moisture is limited.