We like to imagine that our evergreens will stay green forever, but that’s sometimes not the case. While your tree isn’t likely to go entirely bald in preparation for our chilly Des Moines winter like deciduous trees do, it isn’t unlikely to see a few needles shed to make room for new ones, especially in the fall.
Any time your evergreen starts to turn a shade of yellow or brown, we’re quick to be concerned— there are several diseases, pests, and illnesses that could be affecting your tree. If you are noticing discoloration and needle drop, pay close attention to your tree. If the needles are mostly yellowing and dropping from the older branches closer to the trunk, then it is likely to be normal seasonal needle drop, also known as fall needle drop, and it is a natural part of your tree’s life cycle.
Seasonal Needle Drop
Sometimes needle drop occurs so slowly that the aesthetic of your tree and landscape is never compromised, and you won’t even notice the exchange of older needles to newer. Needle drop is most noticeable when several of your trees start to lose needles at the same time– as a seasonal process, this isn’t unheard of. As a natural part of the life cycle, there isn’t much that you can do to fight it, and you’ll have to tolerate the yellowed (or reddish-brown) appearance of your trees for a few weeks to months.
Throughout normal seasonal needle drop, you may notice color changes on the inner areas of your evergreen, and some bareness with needles carpeting the landscape under and around the tree, all before new needles emerge to take the place of the old.
When Yellowing Needles Are a Sign of Trouble
Not all yellowing needles are a sign of seasonal drop, and knowing the difference can help to alleviate your concerns or direct you towards taking proper care for your evergreen.
Yellowing early in the season or the yellowing on newer growth might be a cause of concern. Look for other causes like drought, pests (such as spider mites), or other symptoms in the needles, bark, or roots that could point to an alternative cause for the needles to be dropping out of season. Normal seasonal needle drop happens across the whole tree in the fall, so if you see yellowing in isolated parts of the tree, or discoloration starting in one area and spreading, it could be a sign of distress. If in doubt, our experts are willing to help diagnose tree issues if you have concerns.
Evergreen Trees Prone to Seasonal Needle Drop
Not every cone-bearing tree or shrub is an evergreen, and different evergreens may drop their needles at different rates. Some deciduous conifers that grow in Des Moines, such as bald cypress, dawn redwood, larch, and tamarack, seasonally drop all of their needles in preparation for the fall, so yellowing and dramatic needle loss can be expected.
For evergreens, each species has its own life cycle. Pine trees can be expected to shed every two to five years, while spruce might only shed every five to seven. Others, like the Eastern white pine, tend to have a dramatic shed every two or three years, dropping an entire year or two of needles at once before winter. You might have a sparse looking tree, but it’ll recover in the spring. The Austrian pine and Scotch pines are on the other end of the spectrum, easily covering the loss of their needles so that their seasonal needle drop is barely perceptible.
It can be alarming to discover your evergreen, a stand-out star in many yards here in Des Moines, is dropping needles and looking sickly in the fall when you expect it to be green all year. Keep an eye out for the telltale signs of seasonal needle drop to explain the loss in needle coverage, or possibly for signs of illness that might be affecting your tree. With seasonal needle drop, it’s all part of a natural cycle intended to have your tree looking fresh and full again in the spring.