Even Evergreen Leaves Change Color and Drop in Autumn

First posted on 11-08-2011

During autumn, “evergreen” may be a misnomer when it comes to pines and arborvitae, according to the University of Arkansas Division of Agriculture.

“Deciduous trees may get all the attention for their color change and shed in the fall, but this is also the normal time of year for evergreens, such as pines and arborvitae, to lose older growth,” said Jim Robbins, extension horticulture specialist-ornamentals, for the U of A Division of Agriculture.

“Common landscape plants, such as pines and arborvitae, drop a certain set of needles all at the same time, giving the impression that the plant is sick,” said Jim Robbins, “This significant needle drop is normal.”

There are ways to tell whether the needle drop is due to stress or is the normal fall drop. One is the location of the browned needles.

“If you look at the interior of the plant and you see lots of yellow needles all about the same age or same position, then what you are seeing is normal needle drop,” Robbins said. “If the needles were turning yellow and dropping in patches toward the outside of the plant you more likely have a disease or insect problem.”

Tamara Walkingstick, associate center director for the Arkansas Forest Resources Center of the U of A Division of Agriculture, said that fall is a great time make the best of pine leaf drop.

“It’s the time to start harvesting pine straw for your garden,” she said.

Other landscape evergreens such as magnolia also have seasonal leaf drop, Robbins said, “but in this case, the significant drop occurs in April as a new flush of growth appears.”