Save your plants in the summer heat

The University of Illinois Extension reminds people that summer’s hot temperatures can pose challenges for trees.

“Some trees, such as maples and ashes, instead of scorching, shed their leaves or leaflets while they are green until the trees rebalance the remaining foliage to available moisture the tree can take up,” said James Schuster, a plant pathology specialist with the Extension, in a recent news release. “Some maple and ash trees are very prone to shedding the green leaves and leaflets. Other trees hang onto all their leaves but then the leaf tissue farthest from the veins dries out, turns brown and dies.”

Scorching is the name given to the appearance of leaves that are partially alive and dead due to drying out. Sometimes, scorched leaves can be confused with diseases, Schuster said.

An example would be anthracnose. Anthracnose on oak, maples and ashes seem to be more commonly confused with scorching, especially if the homeowner was not paying attention to their trees before the hot dry weather. Anthracnose likes wet weather.

Drought and drowning often cause similar appearance on the above-ground plant parts,” he said.

“When plants are too wet, the roots may suffocate or drown, or the excessively wet soil may encourage a root rot,” Schuster said. “As the roots die, the above-ground plant parts do not get enough water from the surviving roots.”

To minimize scorching, make sure plants have adequate drainage and are watered correctly during droughts, he said. 

During drought, water deep and infrequently. Plants that are watered properly should be able to go two weeks or more between waterings.  

Plants that are mulched correctly can go even longer between watering. For most trees and shrubs, try and water at least 9-12 inches deep (deeper on sandy soils). Clay soils do not absorb water as quickly as sand or silt so water trees growing on clay at a slower rate to avoid or reduce runoff.

– Daily Chronicle