Plants change with the season
As the season changes, plants change as well. This is true in evergreen and deciduous trees and shrubs as well as our lawn grasses.
The cooler night temperatures and the shorter day length of fall result in changes in the physiology of many of our landscape plants and lawn grasses.
It’s common for azaleas to lose a few leaves now. These are the older leaves on the stem near the center of the plant. They turn reddish or yellow and drop from the plant. This is normal from now until spring. However, if the younger leaves, those nearest the tip of the shoot, turn yellow or brown there is cause for concern. Poor drainage, lack of water or alkaline soils may cause this condition.
Yellow leaves may appear on camellias, gardenias, cherry laurel and oleanders. Again, as with azaleas, these are the older leaves on the stem near the center of the plant. It’s normal for these leaves to drop from the plants now until spring. However, do not confuse scale damage on camellias for normal aging of leaves. Scale insects feed on the lower surface of camellia leaves causing them to become splotched with yellow.
Many of the leaves on sycamore trees have changed from green to brown. Although this phenomenon occurs every year, it’s not caused by a change in day length or temperature. This is not a true seasonal change. It’s the result of insects feeding on the leaves. By the time the damage is visible, there is little that can be done to correct the problem. However, the problem will take care of itself since sycamore trees will soon be dropping their leaves.
Lawn grasses also experience some seasonal changes. The growth rate of lawn grasses slows in the fall. Although this slowdown in growth means less mowing is required, it also means that lawns will not be as attractive as they were during spring and summer. Because of this reduced growth rate, grasses cannot produce enough new leaves to replace the leaves that are dying. The end result is a dull, yellow-green lawn.
Numerous reddish-purple blades throughout the lawn may be visible now as well. Cooler temperatures, injury to the leaf blades from foot traffic, mowing equipment, vehicles, etc, can cause this. It also could be caused by lack of potassium or phosphorus but is more likely the result of cooler temperatures, especially if it did not show up until fall.