It’s no secret, I love palm trees! My passion for all things palmy started at a very young age. In the 7th grade I bought my first Trachycarpus fortunei (windmill palm) off eBay, and in the 8th grade, I did an entire project on growing palm trees in New York City. It gave me the confidence to plant two palm trees outside in New York when I was in high school. It was an experiment on climate change, and an exciting opportunity to make my yard look a little more like the tropical climates I love to forecast in. It turns out, the experiment has been a success because, 12 years later, those same palms are thriving. Are you looking to grow palm trees in a cold climate? Hopefully this post will help! I’ll share how I selected this mild microclimate in my yard, the kind of protection these plants received, and the temperatures they’ve survived.
Why Windmill Palms?
When people ask what palm they should try to grow in cold climates, I always recommend Trachycarpus fortunei (Windmill Palms). It grows new fronds quickly, has a beautiful trunk, takes a long time to get very tall, is spineless, and can handle extreme cold and hot weather too. Trachycarpus fortunei are cold tolerant to 10F briefly without major damage. There’s no other palm that can handle that kind of cold and also provide a dense canopy of beautiful palm fronds overhead. Needle palms and Sabal minor are more cold tolerant by a few degrees, but stay short and more shrubby. Keep in mind, with any palm, duration of cold and wetness is so important to consider. Many palms die from winter rot in northern and wet climates if temperatures get close to their minimal tolerance. However, there are some palms coming back from 0F temperatures in Dallas after the disastrous freeze in 2021 because the duration of winter cold is short and the sun is strong in the south.
Some gardeners push palms beyond the plants’ typical climate of comfort by wrapping them. I’ve use frost cloths and Christmas lights, but in more extreme climates some palm enthusiasts build big boxes with insulation and light bulbs. This is all to keep the palm trees a few degrees warmer on nights that would otherwise be too cold. Trachycarpus fortunei are a easy to protect because of their manageable size. These palms also do fantastic in pots and can easily be rolled into the house, a garage, or even a warm crawl space during the wintertime.
An Aside: Growing palm trees is a sign of Climate Change
Climate change is making it easier to grow palm trees in climates like New York City. It may not come as a surprise. A warmer world means warmer temperatures, but arctic air still exists and will occasionally move in and wipe out a garden that is growing north of where it should be. However, it appears that the arctic outbreaks in New York City are not as strong as the past. Since 2000, 9 winters have been warm enough to grow Windmill Palms in New York City unprotected because temperatures stayed above 10°F. This is a recent warming trend not seen any other time in the past 150 years of record keeping in the city.
Central Park has reported 39 winters with sub-zero temperatures °F since 1871. That’s an average of 1 in every 4 years. However In the past 30 years, it’s only happened in 2 winters (1994 and 2016).
Interestingly, studies show New York City may be getting snowier because climate change is increasing the strength of Nor’easters. Six of the 10 biggest daily snowfalls in New York City’s Central Park have occurred since the year 2000. Snow itself is not a limiting factor for growing cold tolerant palm trees, but snow could give some New Yorker’s the perception that winters aren’t getting warmer. As contradictory as it sounds, more snow is likely a symptom of a warmer climate in New York’s case.
My experience with Windmill Palms
My two Trachycarpus fortunei (Windmill palms) have a pretty modest growth rate. When I planted them 12 years ago, their trunks were less than half a foot tall, and now their trunks are approaching 4 feet. They’ve had a few rough winters which I will detail in a picture collage below, but generally grow about 7-10 fronds each season so the damaged winter fronds are usually just a memory by the time autumn rolls around.
In March 2009 I selected the best microclimate I could find in my parents backyard (a sunny spot with a fence blocking the north wind) and started digging. I thought 4 feet apart would be enough distance for two trachycarpus, but if you’d like to keep the fronds from touching I recommend at least 6 feet apart or planting them at very different sizes so one is always taller than the other. They look great in groups, but for the pool area, I would have preferred to keep them a little farther apart so they both have some room to shine!
In December I wrap the fronds up with rope or garden twine and cover with C7 or C9 christmas lights. These lights get hot so use sparingly. LED christmas lights will not work because they don’t generate heat. When temperatures drop below 20F at night, I wrap my Trachycarpus with frost cloth, but I only turn the lights on if temperatures drop into the mid teens or colder. The lights go off as soon as temperatures begin to warm into the 20s. I don’t like to keep the lights on for long because it can pose a fire risk. Be careful if you use anything electric to heat your plants. Some northern gardeners have killed their outdoor palms from the heat!
Trachycarpus fortunei cannot survive in New York City long term without protection (at least not in its current climate). They will survive mild winters unprotected, sometimes with ease. In New York these palms are typically undamaged by winter if low temperatures stay above 15F. They can return from 10F in New York, but are very borderline with temperatures that drop below that. Every windmill palm I know of that was not protected in the New York area, died when temperatures dropped into the lower single digits in 2018.
Lowest Annual Winter Temperatures
There are more years where Trachycarpus fortunei can survive in the New York City metro than there are years where it cannot. However, it just takes one cold night to destroy a palm that has grown effortlessly for years. We see this time and time again with other cities across the country. Even in warm climates like Florida, every 10-30 years a hard freeze will kill tender tropical palms in much of the state (while native palm species remain entirely unharmed).
Swipe to see how the palms were damaged after the winter of 2019.