Well winter has spring upon Florida rather quickly this year, bringing freezing temperatures that many of my palms trees cannot handle. Fortunately most of these are in pots, so the easiest fix to prevent them from freezing is bring them into to garage. This not only protects them from the frost but protects them from damaging winds as well, since the radiant heat from the house as well as the lighting in the garage will keep them happy.
Now I’m sure many of you however have planted a palm tree or two that are not as cold hardy, and therefore do not have the luxury of just bringing them in to protect them from freezing. If you are one of these people, here is what I suggest. First, you will need some way to provide heat to your protect your palm. Many people will first string a few strands of Christmas lights both around the trunk of the palm and over or through the fronds. Some even place a floodlight or two and angle them up towards the fronds. After placing your lights the next step would be to drape the palm with some sheets or a light blanket, carefully tying them down or if they are long enough weighting them down with a few rocks or bricks. Using these tips should help keep the ambient air around your palm above freezing, and thus prevent it from both frost damage and freezing.
A word of caution, whatever you do, do not use plastic sheeting on your palm, as this can actually trap moisture underneath which may freeze. Some people also use frost cloth, and it should be applied in the same fashion as stated above. However, in my opinion the added expense is not necessary. To make life easier I have also seen pictures of people utilizing plastic webbing to tie the palm fronds up before wrapping in blankets. Once wrapped in blankets a frame is built around the entire palm then the frame covered, which this then provides yet another insulating barrier that can be filled with media or to trap in heat from your heat lights.
If you are trying to protect a palm from a hard freeze, ultimately what you are then trying to is protect the trunk and heart of the palm, which rests at the top of the trunk where the fronds emerge. On top of the above recommendations, I would also wrap the entire trunk with a heavy blanket. Other suggestions are to surround the trunk with a cardboard box, then filling it with mulch all the way to the top, ensuring that you cover the heart area with a thick layer as well.
After 2021’s epic artic freeze that blasted North Texas, many are now reconsidering their choices on what tpe of palm they will be planting in their landscapes. By no means will any of the the above necessarily ensure the survival of your palm from severe freezing temps, especially if you have a palm that is rated for Zone 10 planted in Zone 7, but it will certainly be better than leaving it unprotected. The final suggestion to protect your palm tree from freezing would be to only plant palms that can take sub freezing weather, such as a Butia, Phoenix, Washington, Brahea armata, Trachycarpus fortunei or some other cold hardy palm tree.
For my area here in NE Florida we have not had a sever freeze event in over ten years, and even then we only had a touch of 19F but did have several days at or below freezing. At the time my palm collection was minimal, so protection was not needed. However, that is not that case now so I will definitely be employing these techniques to protect a few in my collection.
If you are looking for other creative ideas hop on over to the International Palm Society’s web forum, Palm Talk, where you’ll find numerous pictures and discussions regarding protecting your palm from freezing and more.