Oregon Department of Forestry News Release
For Immediate Release - Major Media Distribution
August 3, 2012
Contacts: Cynthia Orlando, 503-945-7421
Kristin Ramstad, 503-945-7390
Paul Ries, 503-945-7391
Weather reports are calling for triple digits in some parts of the state this weekend, but even prior to that forecast, signs of tree stress caused by lack of water were already observable in some Oregon communities.
Seems like a good time to remember that when temperatures in Oregon get warm and stay warm, it can take a toll on trees as well as people. The Oregon Department of Forestry suggests a few tips for keeping your trees healthy during times of heat stress.
“Summer temperatures can be hard on trees, especially landscape trees in our urban areas," said Paul Ries, an urban forester with the Oregon Department of Forestry. "Warm weather and prolonged drought can make trees more susceptible to insect and disease problems," adds Ries.
Symptoms of drought
One of the first signs that a deciduous tree – i.e., a tree that loses its leaves in the winter – needs water is that its leaves begin to look dull. More advanced symptoms of needing water are yellowing or browning of leaves, wilting, and curling at the edges.
Leaves may develop a scorched or burned look, turning brown on outside edges, or between leaf veins. Leaves may also appear smaller than usual, drop prematurely, or turn brown but remain on the tree. Evergreen needles may turn yellow, red, purple or brown.
Watering do’s and don’ts
Given their benefits and longevity, trees should be given higher watering priority over lawns. If trees are only provided with shallow water every day, they're probably only getting a fraction of what they need. And, watering trees for short periods of time encourages shallow rooting, which can lead to future health problems for the tree.
To make sure your tree gets the water it needs, saturate the soil within the drip line – that’s the circle that could be drawn on the soil around the tree directly under the tips of its outermost branches. Using a regular hose or a soaker hose, water deeply and slowly – slowly is important, so the water doesn’t run-off. To make sure it gets enough water, keep moving the hose around different areas under the tree.
For conifers, water 3’ – 5’ beyond the drip line on all sides of the tree. Also, if you have a choice, water during the cooler part of the day for all trees. Another way to water trees slowly is to put a nail hole in the bottom (near the edge) of a five gallon bucket. Fill the bucket with water, and leave the slowly leaking bucket under the canopy of the tree. Do this twice or three times per tree, moving the bucket each time.
Other tips: use mulch
Using mulch is a good way to care for trees in warm weather, since mulch helps the soil below trees retain moisture and stay cool. Remove lawn and replace it with a ring of mulch. Mulch can be made of bark, wood chips, leaves and evergreen needles. Apply mulch within the drip line, at a depth of four inches, leaving a six-inch space between the mulch and tree trunk. Mulch will also help discourage weeds.
Don’t plant annual flowers or other groundcovers under the canopy of your tree. Any plants below a tree’s canopy compete with the tree’s roots for moisture and nutrients.
Tree care: always a good investment
Trees and forests enhance quality of life in many ways, providing shade, wildlife habitat, wood and other products, raising property values, and providing clean, healthy streams. Proper tree care - including deep watering of trees during hot summer and warm fall months - pays big dividends in the long run.
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