We’ve had a lot of reports recently about problems with white pines in southern New England, including here in Connecticut. The pine needles, especially the older inner needles, are turning tan or yellow and then falling off, and the trees are looking generally unhealthy, thin or even dying.
Why Are White Pines Shedding Needles?
Unfortunately, it’s not entirely clear what’s causing the problem.
We have had a fungal condition called needlecast in the area for some time which has had minor effects on conifers but now it appears that there is a new combined force which includes four fungi associated with this new condition, including one that was only discovered in CT last year. Each one of those can cause pine needles to turn yellow and eventually fall off, but not all are always found on declining pines.
Another factor is the weather conditions over the past few years, especially the very dry conditions of 2015. However, we’re seeing signs of needlecast on this year’s needles, which suggests that there are things beyond last year’s weather that are affecting our white pines.
The CT Agricultural Experiment Station has a brief update on white pine decline released through the Plant Disease Information Office.
There’s also a helpful document from the UMass Extension office that includes photos of affected trees.
What Can You Do About It?
That’s not an easy question to answer.
Because the fungi associated with white pine decline may not always be present and a true understanding of the root cause is still developing, a fungicide treatment may not always be effective but can be helpful in protecting new needles.
It’s a good idea to have a professional examination of your pine tree(s) before deciding on treatment.
And because affected trees are more susceptible to stressors, such as dry conditions, be sure to keep your pines adequately watered to ensure vigor (but do not water the branches or needles! its best to utilize a soaker hose).
For more information on pine needlecast problems, see our related article on Evergreen Needlecast: What You Need to Know.