Young Trees Need Watering
Tips to give plantings a good start
5/30/2018, 11:51 a.m.
Oregon’s Department of Forestry is reminding urban dwellers of the need to water trees even in spring, especially this year for new plantings because so little rain fell during the month of May.
With trees leafed out and putting on new growth, urban trees need to be watered to survive and thrive. Yet many people in Oregon cities only start watering their trees in the hot months of July and August. By then it may be too late.
Kristin Ramstad, manager of the Oregon Department of Forestry’s Urban and Community Forestry Assistance Program, points to the Learning Landscape arboretum at Meek School in northeast Portland’s Concordia neighborhood as an example of how irrigating trees in spring and summer has helped non-native trees grow faster and healthier.
“Watered every spring and summer since being planted in 2010-12, trees in that arboretum are already much taller than similar trees which got watered only for the first couple of years,” she said.
“Lack of water can cause dieback and even kill non-native trees in Oregon,” she warned. “Trees under stress are also more likely to be attacked by insects. That seems especially true for conifers.”
Ramstad said trees less than three years old should get 10 to 15 gallons once a week from the time they leaf out until early fall. Older non-native trees might need 20 to 25 gallons. “Let the water slowly soak in. The goal is to have the water get deep into the root zone.”
She suggested keeping grass at least 2 to 3 feet away from a tree’s trunk to reduce competition for water. “Mulching around the tree also helps,” she said.
All newly planted trees require watering to survive their first couple years.