Pine Needle Drop: Why Evergreen Trees Still Lose Needles
Needle loss often surprises homeowners. However, pines are known as evergreens, and that label can be misleading. Evergreen trees do not keep their needles forever. Instead, they retain them for more than one year. As a result, when new needles grow, older ones are naturally shed, allowing the tree to remain green throughout the seasons.
For this reason, this process is normal and healthy for most pine trees.
Below is a handy chart from the University of Nebraska’s Backyard Farmer of how long common pine trees grown in Nebraska hold onto their needles:
TWO YEARSEastern white pine
Jack pine (2-4 yrs.) Scotch pine (2-4 yrs.) |
THREE YEARSKorean pine
Japanese Black pine (3-5 yrs.) Japanese Red pine Japanese White pine Lacebark pine Macedonian pine Ponderosa pine |
FOUR YEARSAustrian pine
Red pine Swiss Stone pine |
FIVE YEARSBosnian pine
Mugo pine |
Why Pine Needle Drop Happens
To begin with, pine needles follow a natural growth cycle. Older needles, which are usually located closer to the trunk, drop as the tree produces new growth at the tips of branches. In many ways, this cycle is similar to how human hair sheds and regrows over time.
Because this change happens gradually, it often goes unnoticed. In addition, the shedding typically affects interior needles rather than the outer canopy.
When Needle Loss Is Most Noticeable
Pine needle drop is especially noticeable on the Eastern White Pine[i]. These trees often shed large amounts of older needles at once, usually in late summer or early fall. While this can look alarming, it is typically seasonal needle drop rather than a disease or pest issue.
[i] https://lancaster.unl.edu/watch-evergreen-natural-needle-drop/In some cases, needle shedding is more obvious. For example, Eastern White Pine tends to release large numbers of older needles at once. This usually occurs in late summer or early fall. As a result, the sudden accumulation of needles can look concerning.
Nevertheless, this seasonal change is usually normal and not related to insects or disease.
How Long Do Pines Keep Their Needles
Different pine species retain needles for different lengths of time. According to information from the University of Nebraska–Lincoln Backyard Farmer, common pine trees grown in Nebraska typically hold needles for two to five years before dropping them.
This cycle helps the tree conserve energy and support new growth.
When Pine Needle Drop May Be a Problem
Normal pine needle drop affects older, inner needles. Concern arises when needle loss is excessive, occurs on branch tips, or happens outside the usual seasonal window.
Potential causes of abnormal pine needle drop include:
- Drought stress
- Poor soil conditions or compaction
- Root damage
- Needle diseases such as pine needle blight
If pine needle drop is accompanied by yellowing, browning at the branch tips, or canopy thinning, professional evaluation is recommended.
Should You Worry About Pine Needle Drop?
In most cases, pine needle drop is natural and does not require treatment. Understanding the normal needle cycle can help prevent unnecessary concern and chemical use.
If you are unsure whether pine needle drop is normal or stress-related, a certified arborist can provide an accurate diagnosis.
Not Normal!
Eastern White Pine suffering from Diplodia Tip Blight, exacerbated by drought. Photo by Ariana Brocious, NET News
Austrian Pine suffering from Dothistroma Needle Blight. Photo: Jill O’Donnell, MSU Extension.
