Tuesday, November 1, 2022

This Month in the Garden: Fall Browning and Needle Shed on Evergreens: A Natural Process

Fall Browning and Needle Shed on Evergreens: A Natural Process
If your evergreen’s inner needles are suddenly turning from a healthy looking green to shades of yellow, orange and brownish-red in late summer and fall there is little need for concern…it is all part of a natural process. Each year evergreens will produce new foliage in spring and they prepare by shedding their older foliage in the previous late summer and fall. 
Browning and Needle Shed on Evergreens in the Fall
Shedding of needles and foliage is a natural process that evergreens go through as a way of preparing for new growth once the weather warms. As the days become shorter and temperatures lower, evergreens go through a slight dormant period similar to deciduous trees and shrubs. Many evergreens such as pine, cedar, Chamaecyparis (Hinoki Cypress), Thuja (Arborvitae), fir, hemlock and spruce lose some of their needles every year and may go through a major shedding every three to five years.
Fall Needle Shed on Hinoki Cypress and White Pine in late September-November-Shedding can be light or more pronounced. 
Lightly shaking the branches can help along the natural cleaning process. To examine, look at your tree carefully. Older foliage is shed first so the losses should generally be from the inside out and not at the tips. Prior to shedding the needles appear from green to yellow, orange and eventually brown, remaining on the tree until the process is complete. The actual amount of needle shed on the tree or shrub varies depending on the growing season, temperature changes and amount of rainfall, and can sometimes be sudden. Often the change is unnoticeable but generally the drier the season or more drastic the temperature change the more noticeable the needle shed, a natural cleaning process leading to new growth in the spring.
Fall Needle Shed on Evergreens Showing Previous Year’s Growth. Older Growth is closer towards trunk.
Other species of evergreens in the broadleaf category can also shed their leaves. Evergreens such as holly and laurel retain their leaves for only one year and rhododendron and azalea for one to two years. Leaves will appear yellow before falling but at some times may go unnoticed if new leaves conceal old foliage. This process usually occurs in spring when new growth is appearing but can happen at other times of the year as well. If the whole tree or entire sections of your conifer are turning brown then there is cause for concern and you should have a certified arborist or landscape professional examine it. Otherwise, fall yellowing or browning at the base or inner branches closer to the trunk seldom indicates a serious problem, but is more often part of the natural life cycle of the tree.

needle shed
Conifer Annual Needle Shed
Due to the importance of this subject, this is a repost from my maintenance blog, A Guide to Landscape Design & Maintenance.

Be sure to stop by on the 1st. and 15th. of each month as I continue to share gardening tips, information and horticultural adventures! Until we meet again...be well, and as always...Happy Gardening!

3 comments:

  1. Lee, thank you for this post, it is SO timely for me! We have a Hinoki cypress in this new landscape we moved into in Oct 2021, and I was bit concerned with this year's changes. I've had so many other changes, I wasn't sure (still not 100%) whether the cypress should be a concern or not. But your post certainly lessens the concern.

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  2. Lee, I always got upset looking at the yellow needles of my thujas. Now you have told us that this is a normal process and that I should clear the branches of the old needles. Thank you.

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  3. How interesting and informative (and beautiful)! Thank you!

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