By Dr. Bill Barrick, Executive Director
During the dog days of summer, we may think we live in a sub-tropical climate, but in reality we are still quite temperate in Mobile. Our horticultural hardiness zone is 8b, meaning the average low temperature is 15-20 degrees Fahrenheit. We had several nights in a row in mid-January where low temperatures of 19 degrees F were recorded and daytime temperatures never reached above freezing. In past years, we have been lucky to have these low temperatures for only a few hours in the early morning hours, and for this reason, many of marginally cold hardy palms survived in past winters. But I’m afraid that this may not be the case this year, as I fear many will die from this winter’s severe cold.
As you ride around our city, you’ll notice that the palms that suffered the most were Canary Island Palm, Phoenix canarensis, and Mexican Fan Palm, Washingtonia robusta. Unless the terminal bud of these palms survived, I’m afraid many of these palms will not push new growth this spring. It’s sad to see the Phoenix palms on Dauphin Street at the Mercedes dealership, and numerous examples of damaged Mexican Fan Palms can be observed in several of the Regions Bank branch locations.
So what should be done now? My advice is to wait until March or even later to see if there is any regrowth from the top of the palm before completely removing the palm. I do hope that there will be regrowth and only the damaged fronds will need to be removed.
All over our city, numerous examples of cold damage can be seen on Cycads, Cycas revoluta, also known as Sago palms. I am less worried about cycads and don’t expect we will lose any of them. I think it is safe to go ahead and remove the damaged foliage on those.
There are five species of palms that are reliably cold hardy in Mobile and should be continued to be planted in our landscapes – Needle Palm, Rhapidophyllum hystrix; Cabbage Palm, Sabal palmetto; European or Mediterranean Fan Palm, Chamaerops humilis; Chinese Windmill Palm, Trachycarpus fortunei; and Pindo Palm, Butia capitata.