Saturday, March 15, 2014
Is my palm dead?
Garden, mid-March after our coldest winter in 20 years
Is my palm dead? Lots of people are going to be asking that question over the next few weeks because frankly, the palms look dead. The short answer: maybe, maybe not. Hardy palm legend (and mystery author) Tamar Myers supposedly once said, "don't declare a palm dead until spring, and don't declare one alive until summer."
As many of us in zone 7 discovered this winter, temperatures in the low single digits will cause severe damage to unprotected windmill palms (Trachycarpus fortunei). This was our coldest winter in 20 years and lows in the Washington, DC area bottomed out in January somewhere between 6 degrees and slightly below zero. Interestingly, my own low of 5 degrees in early January only caused significant damage to my "waggie", Trachycarpus wagnerianus. Two other windmill palms, T. fortunei "Nainital" and T. fortunei "Bulgarian", curled their leaflets and looked unhappy, but a week later showed virtually no damage whereas T. wagnerianus looked freeze-dried. Far more damaging were the several cold waves that followed, although subsequent lows were in the 9-12 degree range, showing that frequency and duration of cold is at least as important as the absolute low. As of mid-March, all of my palms are looking pretty rough.
Trachycarpus fortunei "Bulgarian", mid-March
So are my palms dead? Maybe, but maybe not; all I can really do now is cross my fingers and wait. Windmill palms are famous for recovering from massive damage, including "spear pull" and near-total defoliation. There's a very good chance that many of our area's dead-looking palms will put out new growth, but be patient: they may not show any signs of life until June or even July. It's not unusual for the tightly folded emerging leaf ("spear") to pull out after a cold winter, with the palm otherwise showing little damage and recovering quickly. The meristem (growing point) is buried deep inside the palm, with the young leaves developing from it surrounded by the bases of the older leaves. For every emerging spear there are several more in reserve that aren't yet visible. After a winter like this one, most if not all of these developing leaves are damaged or destroyed, leaving the palm to start from scratch. In severe cases the youngest leaves, as well as the spear, will pull right out. But as long as that meristem is still alive, it will recover and (eventually) push out some new leaves. Some growers advise hydrogen peroxide or fungicides in the hole to help prevent rot, but I've never tried this and my palms have (nearly) always recovered from spear pull.
Trachycarpus wagnerianus (left), T. fortunei "Nainital" (right), early February
I'll admit, I don't have high hopes for my waggie. The damage was so severe, and happened so early in the winter, and was followed by cold that damaged even the tougher palms, that I think this might well be the end of my decade-plus experiment with this species. But my "Nainital" and "Bulgarian" still have some green in their leaves, giving me some hope that they aren't goners. All I can do now is take my own advice and wait.
Assuming any palms survive, the tricky part is going to be next winter. Many of these palms are going to be severely weakened and the second winter may well be the death blow for them, even if it's not nearly as cold as the last winter. This happened with two of my waggies several years ago, when they recovered from near-total defoliation but suffered damage again the following winter, even though it wasn't nearly as cold. I'm not sure what to recommend, except to give the plants good care during the coming growing season, and possibly even protecting them next winter to increase their chances of pulling through it.