Extreme heat can cause stress on plants, trees

The last several weeks have been extremely hot and dry for most of Oklahoma. Many of our trees, shrubs and flowers are under severe heat and drought stress, literally facing the plant world version of heat stroke. I am seeing many 2 and 3 year old tree plantings where folks were diligent in watering the first year, even using Tree Gators or similar watering devices but appear to think the trees can survive and thrive on their own now. It is true that the more established trees and shrubs with a more comprehensive root system that goes deeper into the earth can better survive this intense summer heat and access moisture deeper in the soils. But younger trees and shrubs, even in their second or third years still need your help and support when we face these extreme heat conditions.

Take time to observe your conditions. Be aware that open, well drained sandy soils dry out more quickly than tighter, slow draining clay soils so require more human watering support in these extreme dry conditions. Remember that shallow rooted plants like annuals, vegetables and even perennials and lawns will dry out and stress even quicker than trees and shrubs since their roots, (the plant’s soda straws to suck up water) don’t go as deep and the surface soil dries out more quickly than soil further under the surface that isn’t dried out by winds and the hot sun.

Assist your plants with additional water using drip irrigation, soaker hoses, sprinklers or at least hand watering. Most plants need the equivalent of at least 1” of water weekly to deal with this heat and drought. It is best to really soak your plants, getting water deeper into the earth, instead of just squirting the flowers and wetting the dust.

Mulched plants are in much better shape to face the stress of an Oklahoma August inferno and reduces amount of water your trees, shrubs and flowers need to help them through this hot spot so they can rebound with new growth and energy as September eventually delivers cooler nights and some natural rainfall.

Please make time to walk your yard and observe and “listen” to your plants. Are they wilting? Is the foliage a grayish green instead of the usual bright or glossy green? Are your trees and plants dropping many leaves, a natural survival effort to shed part of the canopy and reduce the plant size to the conditions and what the roots can support.

If you observe any of these conditions, don’t just stand there, grab the waterhose and start soaking your plants. Their very survival may depend on the water you can provide. Remember that trees or plants already stressed out from surviving an extreme winter, ice storm damage, and extreme insect or disease damage are more vulnerable to this extreme heat stress as they were already “wounded, tired or stressed”.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: