Trees are doing what trees do this time of year
Cottonwood, pine are ridding themselves of unproductive leaves and needles
Q: I’m not sure if I should be concerned but the cottonwood tree I have seems to be dropping leaves. It’s too early for the annual leaves to fall so is there something wrong with my tree? Also a pine tree has dropped a lot of needles lately too. — T.L., Albuquerque
A: This time of year you can expect established cottonwood trees to drop “internal” leaves and it’s usually not a health issue. In fact it’s what the tree does naturally.
In the spring cottonwoods throw out large masses of leaves to gather as much sunlight as possible to live and grow! The tree canopy is usually very lush and thick. As the season progresses those “internal” leaves don’t gather as much sunlight since the “outer” leaves have grown to their mature size and for the most part block the light.
Well, since those leaves aren’t contributing to the health and management of the tree, it figures they are no longer needed and are “cut off,” so to speak. As long as the leaves are more internal leaves and don’t show any sign of bugs or disease, I wouldn’t worry. The time is coming soon enough for true leaf drop since we’re well into the month of August. Then your property will be awash with fallen leaves. For the pine I want you to determine if this needle drop is coming from the pine tips or needles that were farther down the branch. If the needles are dropping from the tips, and they are brown and crispy, I’d suggest snipping several samples, from tip end including a bit of the green branch, and get to a nursery for a diagnosis.
Another good resource for plant maladies is the Master Gardeners group here in Bernalillo County. Call 292-7144 or 243-1386 and have them guide you to a diagnosis. Just remember that your “sample” needs be fresh and contained in a Zip-loc bag to prevent contamination, especially if you’re going to a nursery. Be POLITE!
But, if the needles that are dropping are from “internal” on the branches or twigs that shouldn’t be a problem. It’s usually the tree releasing two or three seasons’ old growth that isn’t serving a true purpose for the gathering of light to make food for the tree. I learned that the process is called “Needle Cast,” because the tree is casting off old, fairly useless needles.
Now there is a malady called Needle Cast, I don’t know enough about, that the Master Gardeners or the County Ag Agent could be helpful if it’s that disease. But I’m going to hedge my bet that your tree is doing what comes naturally. Dropping needles because it can. If you don’t like the look, rake up and tidy the clusters of fallen needles and be done with it. Sounds like no harm, no foul!
Give your pine a good visual inspection to determine where the needles are dropping from, gather several of the fallen cottonwood leaves to inspect for critters or disease and go from there. Even if it seems odd, I think truly, all is right in your world and your trees are behaving as they should. Happy Diggin’ In!
Speaking of Master Gardeners … Know that recruiting for the Master Gardener Class of 2019 will soon be upon us. The applications will be available ONLY ONLINE, Monday Oct. 8, on the Albuquerque Area Extension Master Gardener website. I’ll give more info and a heads-up as the date gets closer.