Fall is in the air. Going into fall, one of the best things you can do for your landscape is to make sure your trees are well-hydrated going into winter. Hydrated trees are less susceptible to winter kill and sunscald damage on the trunk. Also, the new leaves are more likely to emerge beautifully when spring arrives.
Why water trees in fall?
Deciduous trees, by definition, lose their leaves as winter approaches. Since the leaves on some trees have begun to change color, we know deciduous trees are just about to lose their leaves in the next week or two.
It’s important to water deciduous trees before they lose their leaves. It’s the tiny holes on the underside of the leaves that create the suction that pulls water from the soil into the roots, through the trunk, into the branches. Once they’ve lost their leaves, water won’t move rapidly through the trunk and branches until next spring. Even if there’s water in the soil, there’s not much suction to pull it up the plant.
How to Hydrate a Tree
In order to make sure a tree is well-hydrated going into winter, water the soil thoroughly around the tree. Most of the water-absorbing roots are located around the dripline and beyond. So, concentrate your watering around– and slightly outside of– the dripline.
The dripline is the soil directly under the outer tips of the branches. Don’t bother watering around the trunk, since there are no water-absorbing roots in this area.
Water long enough so that the top 12-18 inches of soil is moist 1-2 days after you water. It takes a while for the water to move down through the soil, so it won’t be that deep right after you water. Since your watering method and soil texture will affect how long you have to water, it may take some experimentation to develop your own system.
What about the recent rains?
If you live in an area that received exceptional amounts of rain in September, check the soil before watering. If the soil is moist in the top 12 inches, Mother Nature has taken care of watering your trees for now. Be sure to recheck the soil in October, since warm fall days can cause soil to dry rapidly.
What about evergreen trees?
Evergreen trees like pines and spruces retain their leaves (needles) year-round. Even though the needles can still pull water up the trunk in winter, they still need to be watered sufficiently in fall.
This is especially if you live in an area where the soil freezes for long periods of time. Naturally, if the soil is frozen, even evergreen trees can’t draw any water up the tree. In addition, if the tree is in a windy site, the lack of water can cause the needles to turn brown on the windy side, resulting in “wind burn.”
Should I fertilize my trees now?
Don’t fertilize trees in fall. Fertilizing can promote new growth, which interrupts the natural processes that prepare the tree for winter. This can reduce their winter hardiness. Out of all the miracle products on the market today, smart watering will give you the best results.
What about pruning in fall?
The best time to prune many trees is in late winter (Feb-March). Taking off a few branches now is okay if it’s necessary. However, just like fertilizing, pruning can stimulate new growth, which reduces the winter hardiness of the entire tree.
In conclusion, over the next week, take some time to water your trees. You’ll be rewarded with healthy, winter-hardy specimens that leaf out beautifully in spring.