|The CSFS offers the following tips to keep trees healthy during summer drought:
- Mulch. Mulch is an inexpensive solution to retain soil moisture and save water. Apply 4 inches of organic mulch onto bare soil within 2 to 3 feet from the base of the trunk of a newly planted or small tree, and up to as wide as the branches of a large tree (removing any grass first, if necessary). Do not allow the mulch to contact the trunk directly.
- Water a wide area. Tree roots can spread much wider than the height of a tree, with most absorbing roots in the top foot of soil. Apply water to soak the entire area underneath the full span of a tree’s branches.
- Water slowly. To ensure soil penetration, use a deep root fork (inserted 8 inches or less), soaker hose on low setting or soft spray wand to apply water gradually to the full area.
- Keep the yard green. Trees located in irrigated lawns generally do not require additional water, as long as the area surrounding the tree receives adequate moisture. Conversely, a dry, yellowish yard means the roots of any trees are also dry.
- Provide enough water. Use a ruler to measure your tree’s diameter at 6 inches above ground level. For trees with trunks 1-3 inches in diameter, apply 10 gallons of water for each inch of tree trunk diameter once a week. For medium-sized trees (4-9 inches in diameter), apply 10 gallons of water for each inch of trunk diameter three times a month. For trees over 10 inches in diameter, apply 15 gallons of water for each inch of trunk diameter twice a month.
- Focus on new and non-irrigated trees. Water newly planted trees and seedlings more frequently than once a week, following the rates listed above, as they have less-extensive root systems. To avoid stress during drought conditions, trees that do not receive water from sprinkler systems or irrigation can also benefit from additional water.
Please visit csfs.colostate.edu/colorado-trees/selecting-planting-and-caring-for-trees for more tips on tree watering, planting and general care.