PLANT CARE TIPS

The Effects of Drought

This past season has been one of the driest seasons on record. This stress, compiled with very high temperatures has caused sometimes irreversible damage to our trees.
Water is the most limiting resource for tree and plant growth. Water is necessary for nearly all biological and biochemical processes within plant cells. Water is also necessary for uptake and transport of nutrients. When soil moisture is deficient, trees react by allocating energy differently. When water is limited to the point of plant tissue or biological process damage, trees will begin to decline, sometimes to the point of death. Resistance to insects and disease is also reduced or lost when moisture is deficient. Our arborists know that come next season, we will be seeing more of diseases such as cankers, vascular wilts, and root rots. Insects, particularly wood borers will also take advantage of our water-stressed trees. Many drought-stressed plants also show increased sensitivity to de-icing salts, air pollutants, and pesticides. In many situations, flower production will be limited on flowering trees.

Some signs of drought stress are;

• Curling, mottled, or browning of the edges of leaves
• Smaller than normal leaves
• Leaf drop
• Pre-mature fall color
• Twig and branch die-back
• Bark cracks

Trees growing in native soils and environments usually adapt better to drought situations than trees we plant in our landscapes. There are several reasons for this some of which are: poor species choices, planting in the wrong site, planting too deeply, mulching too thickly, or leaving burlap and/or ties on the rootball.
These situations cause root hairs (the fine absorbing part of the root) to die. When we finally do get rain, the roots can’t take advantage of it.
• Supplemental watering of trees can be timed to help trees recover water and minimize pest problems on surrounding plants. Water to the equivalent of 5 gallons per inch of trunk diameter, weekly. Evergreens need to go into winter with an ample supply of moisture.

• If you have an automated irrigation system, set the timer to go off in the very early hours of the morning (pre-dawn). This will minimize evaporation in addition to minimizing disease caused by prolonged wetness on leaves.
• If hand-watering, invest in a water wand or other shower-soaker type nozzle. This will allow you to direct water beneath the plant to soak the soil and avoid wetting the leaves, especially if the only available time you can water is in the evening.
• The use of organic mulch such as wood chips (without landscape fabric barriers on the soil) is the healthiest practice for plants. Mulch keeps roots cool, suppresses weeds and conserves soil moisture.

Our certified arborists are available to assist you with any tree or landscape related problem.

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