Drought-Stressed Foliage

 Plants have evolved ways to cope with  this dryness and heat. They may begin to go dormant early in the year, with leaves going dull and dropping off. But, when we see our plants in our garden looking like this, we worry. These photos show premature leaf drop on a deciduous tree (Yellowwood), on a perennial salvia, and on a native  wildflower, Amsonia. Supplemental watering may be called for in order to help some garden plants make it until fall’s cooler temperatures and rains.
drought-streesed foliage

Yellowwood tree dropping its leaves due to drought stress.


Drought-stressed salvia


Drought-stressed amsonia

I’m letting the Yellowwood tough it out. Previous years of seeing leafdrop on this tree make me think this is a tough tree, and will make it fine. The salvia is a spare plant out in the distant, neglected part of the garden, far from a hose. She will have to make it on her own. The Amsonia I will force into dormancy by pruning off all the foliage at the ground. Experience has taught me I can rely on her emerging next spring even after such treatment.

With the evergreens and conifers, by the time you notice a dulling or discoloration of the foliage, it is too late for supplemental watering. The plant is toast. Monitor the moisture under those conifers and evergreens, water if you can, and refresh your mulch to help retain soil moisture.
Water supplementation during periods of prolonged dryness is essential for a green, beautiful garden. Don’t let the soil dry completely before beginning to water your plants. Dry soil seems to reject water, especially water applied too quickly. I prefer to pre-water an area, allowing that water to soak in, and then hit the area again in an hour or so. When watering large areas like lawns, I will try and water at night with the sprinklers to reduce evaporation.  Pots and containers will need watering daily in weather like this. Don’t forget to apply a thick layer of mulch to help retain soil moisture. Mulched gardens need to have the mulch pulled back in order to accurately assess soil moisture. A common mistake when watering is to assume that if the mulch is wet then the soil is wet. Better pull some mulch back and check.
Like most gardens, mine has areas of greater importance and areas of near neglect. Close to the house I will water first and often. Further out, beyond the hoses, the plants are on their own. As someone said, Darwin is a ruthless gardener when it comes to survival of the fittest.





Mike Rushing

Mike and Paula Rushing have been gardening in St. Clair county since 1990, and In Forest Park since 2007. A Jefferson County Master Gardener and course instructor at Master Gardening classes, Mike also volunteers weekly at the Birmingham Botanical Gardens.

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