Evergreens Turning Brown? Seasonal Needle Drop Explained

In the fall, coniferous trees like evergreens shed older, interior needles. Seasonal needle drop, or the time when evergreens are turning brown and pine trees are losing needles, is a regular, natural part of a coniferous tree’s life cycle.

Knowing how to tell seasonal needle drop from disease can help bring you peace of mind when it comes to the evergreens and pine trees in your backyard. Read on to learn more about fall needle drop in evergreens.

What is Seasonal Needle Drop?

From late August to October, you can spot conifer needles yellowing. The process of pine conifer tree needles turning brown in the fall is known as seasonal needle drop, where inner needles naturally age while outer, newer needles stay green. 

What’s Normal Needle Drop for Each Species?

While each species of conifer experiences seasonal needle drop, the timing of shedding and its patterns can vary. Here are some examples of how each species goes through seasonal needle shedding:

• Pines – Pine trees, such as Eastern white pines, experience a dramatic needle shed every 2 to 3 years.
• Spruce and Fir – These trees show off subtle interior yellowing while the outer tips stay green.
• Arborvitae, Cedar, and Cypress  – Interior needles turning brown is expected, but the tips stay green.
• Hemlock – The interior of these trees gradually thins over the season.

Normal Needle Drop vs. Disease & Stress

While evergreens browning in the fall is normal, knowing how much needle drop is normal can help answer the question, ‘Is my pine tree dying?”

Yellow and brown interior needles with healthy outer tips appearing uniformly across the canopy during the fall are symptoms of normal needle cast. Tip dieback, banding or spotting on needles, whole branches browning, sticky residue, webbing, or cankers are signs that your tree is in trouble. 

What to Do (And What Not to Do) About Needle Drop

If you’re worried that your tree losing needles is from disease rather than seasonal needle drop, there are a few fall tree care tips to ensure your tree is properly prepared for the upcoming dormant season.

• Do make sure to water during the fall. Deep watering trees before winter helps them stay healthy during the winter. 
• Do mulch. A 2 to 3-inch mulch ring around trees will help insulate your tree during cold weather. Make sure to avoid volcano mulching!
• Don’t overwater. Water adequately and respond appropriately to weather and soil conditions to ensure proper watering practices.
• Don’t overfertilize. A soil test will tell you how much fertilizer you need to use.
• Don’t prune green tips. Green tips are a sign of a healthy tree!
• Don’t panic prune. Interior needles turning brown are normal and will shed on their own.

Species Quick Guide

How to tell seasonal needle drop from disease can be tricky. Here is a quick guide on what to look out for:

• Eastern White Pines – A dramatic fall shed is normal, but if the tips of the needles are brown, you should investigate for further symptoms of salt, heat, or drought stress.
• Norway/Colorado Spruce – Interior shed is fine, but black dots on the needles and brown outer needles may be a symptom of disease.
• Arborvitae – While inner needle browning is normal, brown outer fan tips may be caused by winter burn and drought stress, or a fungal disease
• Fir/Hemlock – Interior needle shed is normal but check for pests such as adelgids or mites if tips fade.

NEED FURTHER INFO ON HOW TO TELL IF YOUR PINE TREE IS DEAD OR DORMANT?