By Linda Summers, Master Gardener
I first developed an appreciation for water back in 2005 when my husband and I visited our son who was in the Peace Corps in Guatemala. I can still picture a woman carrying water in a jug on her head up to our son’s cottage so that we would have water to wash with. I came back to the States knowing how lucky we were to have clean water to drink, hot showers, indoor plumbing and labor-saving devices such as washing machines. No one can deny the importance of water to life—human, animal, or plant. Up to 60 percent of the adult human body is water. Water makes up 80 to 90 percent of herbaceous plants and about 50 percent of woody plants.
Although Southern Illinois has been blessed with an abundance of rain in May, there is always the possibility of another hot, dry summer. Container grown plants such as what you may have purchased from your local nursery are largely planted in soilless or organic mixtures and accustomed to being watered every couple of days. After transplanting, these plants will need 3-4 weeks for their roots to grow into the surrounding soil.
Temperature, plant species, light and soil conditions influence a plant’s ability to take up water. Drought as well as excess moisture can severely stress a plant. So what is the “rule of thumb” for watering newly-planted trees and shrubs? According to the University of Illinois Extension, newly-planted container grown or balled and burlapped plants should be watered every few days with a gallon or two of water until their roots begin growing into the surrounding soil. It is important not to drown the new plants because excessive watering, especially in our heavily clay soils, drives out the air, and the plants basically suffocate.
A simple guide for watering newly-planted trees is this: 1 ½ to 3 gallons of water for each diameter inch of trunk every 5-7 days if there has been less than ½ inch of rain during the week. Keep in mind that if the weather is particularly hot and windy, then the soil will dry out faster, and you may have to water every 3-5 days. Our soils tend to be a heavier clay, and trees may require less frequent watering.
Check to see if your tree needs water by checking the surrounding soil as well as the backfill around the tree. If the soil is dry in the top 1-2 inches, then it’s time to water your tree. Many people think that once their tree or shrub is in the ground, then nature will take over and their job is done. However, supplemental watering of recently planted trees and shrubs should continue for at least two years after planting—until the plant is well established.
By following these guidelines, you protect your investment in your landscaping and ensure the viability of your trees and shrubs. For further information, please contact your local library or the University of Illinois Extension office. You may check for gardening information online at http://web.extension.illinois.edu.
Don’t Forget to Water Those Newly-Planted Trees and Shrubs!