when inner conifer needles turn yellow or brown

inner foliage of Chamaecyparis conifer browningDON’T PANIC: Nothing’s wrong, and they’re not all dying in unison, I promise. Though we commonly call them “evergreens,” conifers such as pine, arborvitae, spruce and Hinoki cypress (above) lighten their load of old needles (the inner ones) in late summer and fall, with a show of yellowing or browning that can scare a gardener at first.

This phenomenon should not be confused with browning at the tips or overall yellowing or browning that can happen at other times—such as from winter desiccation; from the effects of roadside salts; from pests and diseases (including diplodia tip blight in some pines, or phomopsis tip blight in spruce and non-resistant junipers, or similar looking kabatina in junipers); or from drought. (See what road-salt damage and winterburn look like by comparison in these photos.)

inner needles of white pine turning yellow and brownThe browning I noticed in late July on my Eastern red cedar in the front yard (Juniperus virginiana) is suddenly showing up as gold or rusty-brown or a progression from one to the other on many other conifer species. The Eastern white pines (Pinus strobus), above, with their long needles, are always the most dramatic, turning what looks like mostly gold at first. Hard to believe the plant will be OK.

But in fact inner needle-drop is a normal part of the life cycle, though the rate varies by species, and can also accelerate if environmental stresses like dry conditions or pest infestation have affected the tree or shrubs in a given season.

Inner foliage of conifer browningBefore you call the arborist in, though, go inspect: Look at a branch closely (such as in the Thuja occidentalis, above), to identify where along it the fading foliage is. I found the illustration below on a Michigan State University Extension factsheet, showing the natural aging and shedding cycle (again, it varies by species how long till leaves are shed).

The losses should generally be from the inside out, not at the branch tips. Inner needles are the oldest, and as they age and get shaded by new growth farther out, they photosynthesize less effectively and are eventually shed. The plant lightens its load, and good thing, since snow and ice may be coming and extra needles could hold too much weight for the longer branches to bear.

browning inner Chamaecyparis needlesAll conifers do this, just in varying degrees (that’s a Thuja plicata just above), and at various speeds from every couple of years to every five or longer. In fact some, such as metasequoia and bald cypress and larch, do it thoroughly every year–the so-called deciduous conifers. But that’s another story.

Speaking of evergreens: Some broadleaf ones such as Rhododendron will be pushing off old, useless foliage now, too. The only thing I’m worrying about there: the big old leathery foliage is falling into the frogpond and making the tenants angry. As the official janitor, my workload is temporarily increased, but if I don’t keep up I could have an amphibian riot on my hands.

factsheets on fall browning of conifer needles

  1. D Daniel says:

    It is mid May in the USA South and my trees (like the one shown above) are shedding yellow orange needles (a lot of them).
    Would this seem normal this time of year?
    What should be cut off or not cut off?

    They are old trees – at least 25 years old. I top them to keep them away from power lines.

    Thank you for this site and for any helpful comments.

    1. margaret says:

      Are the needles that are being shed all inner ones, not close to the tips of branches? I have some leftover inner needles shed (the process began last fall and not everything fell yet, though it turned brown and just hung on). You don’t say what species of conifer these are and if you like you could send a photo to awaytogarden at gmail dot come.

  2. Nora Crane says:

    Hi there. I’m wondering if you’re familiar with Pom Pom Baby Blue Sawara Cypress. I included one in my front bed design and it was gorgeous initially but now the insides of the Pom Poms are turning yellow and brown. I’m thinking too much water, as after the bed was installed the fall rains started and not that much sun. Any thoughts? Thx.

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