This “evergreen” isn’t dying even though its needles suddenly went from green to golden-yellow in fall. It’s a larch tree, which normally turns color each fall before dropping its needles like a leafy tree. George Weigel

The evergreens that aren’t

The leading misguided cause of concern comes from needled trees and shrubs that naturally lose all of their foliage each fall, as do leafy trees and shrubs such as dogwoods, maples, lilacs, and hydrangeas.

Just because a plant grows needles instead of leaves doesn’t automatically mean it’s an “evergreen.”

Bald cypress, larch, and dawn redwood are three common landscape needled trees that look like evergreen pines, spruce, junipers, and firs in summer but then turn shades of gold, copper, or russet in fall before dropping their needles.

That kind of discoloration and complete drop alarms those who assume all needled plants are evergreens and aren’t aware that total annual needle drops are normal for those species.

This Eastern white pine isn’t yellowing because it’s in trouble. It’s normal for this species to lose its inner, older needles in fall. George Weigel

The inner-needle drop

All needled trees and shrubs drop some of their needles each year as the branch ends grow and plants shed inner, older, and increasingly shaded needles that are no longer needed. Most needled species hold their needles for three to five years before gradually shedding them.

However, a few species keep their needles for only two seasons, meaning they shed a lot more all at once each season than most others.

Best known of that lot is the native Eastern white pine, a bushy tree with long green needles. When white pines begin to shed their second-year needles in early fall, trees can look more yellow than green.

Falsecypress (Chamaecyparis), Japanese red cedar (Cryptomeria), and a few other pine species are others that sometimes look alarmingly yellow in fall.

Needle yellowing can be more pronounced some years than others. Falls that follow hot, dry summers or other stressful-growth spells can lead to more of a drop than usual.

Dead branches show brown under the bark and generally snap rather than bend under moderate pressure. This live branch is green under the bark. George Weigel

To worry or not?

The first way to sort out the difference between normal needle yellowing and trouble is to know what plant you have.

If you know you have a bald cypress or a larch, for example, enjoy the fall-foliage show and take comfort that new needles will replace the dropped ones next spring.

Or if you know your “evergreen” is a white pine or a Hinoki falsecypress, be ready for some needle yellowing each year,

With the latter group that doesn’t drop all needles, the telltale sign between normal and trouble is the location of the yellow needles.

The yellowing should be confined to the inner parts of the branches with at least a few inches of healthy, first-year growth at the tips. If that’s the case, the plant is fine, and assuming no new trouble over winter, new growth will push out from the branch tips next spring.

However, if needles are yellowing, browning, and dropping the whole way to the ends of the branches, that’s a sign of potential trouble.

The banded discoloration of these Douglas fir needles indicates possible disease trouble. George Weigel

Other reasons for concern

Also check the nature of the color change. If the needles have reddish or dark spots or bands of two or more shades, those are signs of potential foliage diseases – especially if the discoloration is affecting needles at the branch tips or working its way up a tree.

Some diseases, such as needlecast and diplodia, are often fatal ones, although it may take several years for an untreated tree or shrub to die completely.

Needles that look dotted or “stippled” or that are covered with small bumps or white cottony growth are likely being attacked by common landscape bugs, such as spider mites on dwarf Alberta spruce, scale on yews, and woolly adelgids on hemlock.

In the case of bugs and disease, insecticides or fungicides might be needed to fend off attacks in progress.

Occasionally, needled plants will drop needles due to non-disease and non-bug stresses, such as an unusually hot spell or saturated soil from excessive rain. In those cases, it’s possible there’s still enough life left in the roots for the plant to push out new growth the following spring.

If you’re in doubt, two simple tests will help you determine whether a bare branch is dead or not.

One is the snap test. Dead branches turn brittle and will snap under pressure, while live wood is more pliable and will bend under moderate pressure.

The second test is the scratch test. With a finger nail or small knife, scrape off a small piece of bark and look to see whether the tissue underneath is green or brown. Green indicates life, while brown indicates the tissue has died and dried.

If you’re still not sure, wait. Give those yellowing “evergreens” a chance until spring to see if new needles happen.

The last thing you want to do is cut down or dig out a plant that you think is dead or dying when it’s really just behaving normally.