Looking around my landscape, many of my shrubs and trees are coloring up and starting to lose their leaves. My viburnums and dogwoods are turning a lovely purple. The maples are aflame in shades of orange and yellow. Then my eye turns to the white pines and arborvitaes. Those are turning brown too. Should I panic? It depends.
Most evergreens retain their leaves for one to seven years. Spruce, arborvitaes, pines, and false cypress shed some small portion of their needles yearly in the fall the same as deciduous trees. Yews lose their older needles in the early summer.
In response to environmental stresses like a long, hot, dry summer and fall like the season we just had, a higher proportion of needles are shed. These are primarily the older needles on the insides of the branches. As long as the outside of the plant is still green, this is perfectly normal. Mine are. No need to panic.
Of more concern is when a whole side of a plant turns brown. This is most often due to environmental stressors like wind or salt. Evergreens are very susceptible to water stress. If the side of the tree that is exposed to the most wind browns, desiccation due to strong winds are your culprit. If they are planted close to a roadway, salt spray can cause tips to yellow and then brown.
Diseases like Juniper twig blight are another cause of needle yellowing and death in evergreens. This is a fungal disease that often affects growing tips. Symptoms are seen in the spring on new growth. Treat this fungal disease with a copper-based fungicide.
The key difference between normal needle shedding and environmental damage, or disease is where the brown needles are located. Inside branches ok- tips bad.
Young trees are more prone to water stress than older ones. While all evergreens are fairly shallow rooted, newer shrubs have had less time to put down good roots. Ensure newly planted evergreens are watered adequately going into winter.
There are anti-desiccation sprays on the market that you can spray on your conifers, as well as broad-leaf evergreens like pieris, azaleas and rhododendrons. These sprays work by coating the leaves with an oil or polymer and preventing water loss. These are best used in December when the plants are dormant. It does wear off over time, so reapply in late February /March to protect from strong late winter winds.
I enjoy fall the most of all the seasons. I love the smell of wood smoke, the colorful leaves and crisp bite in the air. And I won’t fret as some needles fall too.
Photos- Upper left Chamacyparis 'Crispii' in my yard with a few brown inner needles.
Upper right Chamacyparis 'Filicoides' close up of inner branch. No brown near the tips.