The windmill palm, Trachycarpus fortunei, is the most cold hardy of the arborescent palms found anywhere in the world – at least as far as we know. Originating from central China and adjacent parts of southeast Asia, it is grown in far flung parts of the world these days, withstanding surprising amounts of cold, wintry weather. If you’ve seen a picture of a palm tree with snow covering it, most likely it was a T. fortunei.
It has become such a common feature in “tropicalesque” temperate gardens that having one is no longer a big deal nowadays. In nature it lives in humid continental climates that range from cool to hot in summer, and quite frosty in winter. For this reason it can be grown in both hot and cool summer areas, provided winter lows don’t get too cold.
Trachycarpus fortunei is a single stemmed, arborescent palm of relatively cool mountain forests. The trunk typically attains heights up to 10 meters (~30 feet), however vigorous ones can go 13 meters or more (a little over 40 feet). It’s trunk is quite narrow, no more than 30 centimeters in diameter, and usually covered by a thick layer of old leaf bases that look exactly like a fibrous plant husk. Some older trees have clear trunks that are grey in color.
The fronds are palmate, meaning they have a long leaf stem (petiole) that ends in a fan-like frond composed of fused leaflets. These grow up to 2 meters long, are very regular in appearance, are normally dark green, and very nearly round, hence the common name windmill palm. The petioles are nearly bare except for a two rows of small spines, and can be up to a meter long. The fan is composed of 30 to 50 leaflets, each up to 90 cm long. They can be held straight out in some trees, forming a true fan shape, or droop considerably in others (much like the leaflets of Livistona chinesis). These characteristics are consistent within a tree, and so are due to genetic rather than environmental factors.
Flowering commences in mid spring. Clusters of flowers (called spadices) emerge and elongate into downward arcing scapes up to a meter long and carry hundreds of flowers each. This palm is dioecious, meaning trees either carry female or male flowers. Flower color is creamy yellow, though the female flowers are bit more green. Male trees can also have spadices that have hermaphroditic flowers (having both female and male parts) and these can set viable seed. The kidney shaped seeds mature to a blue-black color by late fall and winter.
The exact native range of T. fortunei is not well known since it has been cultivated for centuries in China and Japan. Most sources list it as being native to elevations of no more than 2400 meters anywhere south of the Qin Mountains of Shanxii Province in north-central China, and westward through Sichuan and up to the edge of the Tibetan Plateau, with the apparent main distribution having been in the Yangtze River Valley. The species is also reported from Myanmar, Vietnam, India, Nepal, and Bhutan, where it is most likely naturally occurring. It is found in Taiwan and southern Japan, but its occurrence here is most likely a product of cultivation.
Nowadays this palm is found usually near human habitation, so the exact habitat type it originated in is unknown. It is found near cultivated fields, as yard trees, in plantations and occasionally in forests. It is most commonly seen in warm temperate to subtropical mountains or hills throughout its range.
In cultivation this palm has been grown even in areas with distinctly cool temperate climates including much of Europe (as least as far north as the UK, Ireland, Belgium, Holland, France, Germany, Denmark, southern Scandinavia, and westward to Bulgaria and Crimea), North America (north to coastal British Columbia, Canada and coastal areas of Washington State and southward, and in the eastern USA as far north as coastal Virginia and the deep south states), as well as Tasmania and New Zealand (where it is considered an invasive species). Here in Japan it is naturalized to low mountain forests, and though volunteer seedlings even show up occasionally in my small garden, I wouldn’t call it a pest species.
Much has been written about and asserted concerning the limits of this plant’s ability to endure cold. It is not uncommon to hear of people growing it in truly cold winter climate areas such as southern New England, the southern Midwest states, and the southern plain states in the USA. Mind you these areas rate as cold as USDA zone 5 many winters.
Despite these reports, without some fairly serious winter protection, this palm isn’t likely to endure anything lower than -12 C (10 F) and remain a viable plant in the long term. Still, that is very impressive for a tall trunked palm. Can a mature, well sited specimen endure colder temperatures and live? Sure, perhaps. Severe cold snaps, if fairly short in duration, most likely will be endured, but there is a limit to this as well.
Of course, if you wish to go the extra mile and protect your trees, you can extend its growing range remarkably farther north provided the soil only superficially freezes. With that in mind, this palm is fully cold hardy up to USDA hardiness zone 8 (even in cool summer climates), and with good winter protection can certainly endure zone 7, and possibly even zone 6 (there are plenty of folks who said they’ve succeeded). Anything colder than that and you’ll need a greenhouse or equivalent winter protection.
Folks cook up all kinds of novel ways of keep their palms alive in winter including completely wrapping them with fleece or cloth, making miniature greenhouses around the whole tree (sometimes just the crown), protecting the crowns with straw or similar materials, knocking snow off the fronds, mulching the ground around their bases, and even wrapping their trunks with Christmas lights! These methods can work wonders, but as you can imagine, as trees grow it becomes increasingly more difficult to protect them. There is a whole wonderful world of “zone deniers” out there that will go to almost any length to keep their prize plants alive in less than perfect conditions.
With cold hardiness out of the way, let’s consider other needs of this palm in the garden. It grows very well in full sun if the roots are well watered, but the fronds will tend to grow more compact. In a more sheltered spot the fronds will be longer and the tree will have an overall cleaner look on average. This tree also does fairly well in moderate shade, though in truly deep shade it will be spindly and unhealthy. Some growers report that the foliage will shred fairly easily in windy climates, making them unsightly (you really can’t please some people!).
In nature it most commonly grows on well developed loam soils, though this does not seem to be a requirement as trees do quite well in the sandy soils of north Florida. Likewise, clay soils do not seem to be much of a problem since this tree is commonly grown in the southern states of the USA, famous for their red clay. The Royal Horticultural Society’s website even lists chalk base soils as adequate. Soil reaction is optimal from medium acid to around neutral (~pH 5-7), though this tough palm can handle more acidic or alkaline conditions as well. It certainly thrives in Japan’s acidic, volcanic loam soils. Fertilizer can be applied (especially in potted specimens), but most soils have enough natural nutrition to keep this tree happy. Propagation is from seed, which is said to be rather straightforward.
Diseases are thankfully not that bad for this palm. Occasionally scale and aphids can cause infestations. Root rot is a problem and can cause the tree to die suddenly and completely, but this condition is rare (I do see this fairly often in wild trees in the forests of Japan though). Leaf spot can also be a problem, but mostly is unsightly. Harrison and Elliott list T. fortunei as moderately susceptible to lethal yellowing (a systemic bacterial disease). Though incurable, the disease has been successfully controlled with oxytetracycline HCL (OTC). Trees have to be treated repeatedly, and even if the bacteria are suppressed enough to allow normal growth, reinfection may occur.
A few interesting details about this palm. It was first introduced to Europe by the famous German physician/botanist Philipp Franz von Siebold in 1830, presumably the first westerner to see this species. Oddly enough, it wasn’t described until 1850 under an illegitimate name, and later in 1861 by its present name. Though Siebold was the first to discover this palm, it was the Scottish plant collector Robert Fortune working for the Royal Horticultural Society who brought the palm into England in quantity starting in 1849, and hence it was named after him. Interestingly, Kew had received a seedling from Siebold’s original collection as early as 1836. It is odd how some things work out.
T. fortunei has been cultivated for centuries in China and Japan mostly for the fibers derived from the old petiole bases. Especially in times past these were used to create fabrics, brooms, brushes, and doormats. The fruits are also a source of wax and a hemostatic drug (eFloras.org).
Until recently, a dwarf growing compact form, ‘Wagnerianus’, was considered a separate species. Currently most botanists do not consider it distinct from T. fortunei, probably in part due to the fact that no known wild populations exist (and therefore no type material for botanical analysis). It was found in cultivation in Japan a couple centuries ago, and little is known about its true origins. Regardless, it is very distinctive in appearance, and is true from seed, so for growers it is definitely a different palm. It is much more compact in all respects and coveted as a garden plant, being called “much prettier than fortunei” by most growers. Luckily, it seems no more difficult to grow than the typical type, and is just as cold hardy. Truly, this palm deserves a separate article.
Here’s the perfect cold hardy palm if you just can’t live without that tropical look. Moderately fast growing, with few requirements other than a relatively mild climate, this palm’s a winning candidate for tropicalesque gardens everywhere.
30 Replies to “The windmill palm, Trachycarpus fortunei, king of the cold hardy palms”
Can I partition my Trachycarpus fortune? It has 3 separate trunks. Can I create 3 plants from this one plant?
T. fortunei is not a clumping palm by nature, so it is likely that you have more than one plant involved. If the plant is in a pot, you can carefully tease the three trunks apart, but try to not damage their roots as much as possible. If the trunks are actually part of one plant, then I’d say you have a different species, probably Chamaerops humilis, the European fan palm. Separating their clumps or smaller offsets can be difficult if you’re not careful though, leading to them weaken or die. Good luck!
Can anyone tell me if this plant is suitable for an indoor pool area. i am concerned about the effect of chlorine on the plant.
I’m not sure, but I’d say you’ll have no problem as long as you don’t get too much pool water on the roots. This is a pretty tough palm species.
i have a plant of this about 12 years old growing in a large pot. I bring it in for the winter and outside in the spring. It is truly a tough plant. It can go from indoor light to full sun with no burning. Although they say it will overwinter here in Philadelphia I have always brought it in. Carefree and as easy to grow as any other tough plant, It must go outside each summer to thrive.
Just a geographic note:
Windmill Palms grow up the East Coast of the USA well north of Virginia. They can be found growing in coastal locations from Maryland to Connecticut (zone 7)unprotected. Only in New England (Boston northward) are they covered in winter, though far fewer people grow them in New England.
I’ve seen those reports too Jim. Time will tell how long they endure. I zone push all kinds of plants here in Japan as well, and some make it for many years. Some don’t, or eventually get taken out!
what can you tell me about any growing in Connecticut?
Honestly, I know nothing about them in Connecticut except the few posts made about them in various forums. I also saw the tree on your website. It will be interesting to see how long such specimens persist over time.
I particularly like T. fortunei var Wagnerianus. A very neat charming little palm when small. I have found it will grow in warmth and humidity too with high rainfall, particularly if grown in a terracotta pot. Unfortunately you then have to irrigate a lot in the dry season but it stops them rotting grown like this. Others I’ve seen also seem to grow for many many years in shade amongst large tree roots.
Its a very unusual palm in our area amongst the foxtails and Dypsis of the palm world and very expensive. Well worth trying.
Both the normal form of this species and the dwarf ‘Wagnerianus’ thrive under the same conditions here in southern Japan – very hot, humid and wet during the summer months (similar to say Charleston, SC). In cultivation I’ve seen no difference between the two here, though only the normal variety is found growing “wild”.
Thanks for the head’s up on the spelling error, I’m sure there are hundreds of them around. BTW, since this form has no type specimen from a wild population it does not have varietal status, so would be referred to by the cultivar name ‘Wagnerianus’ instead of v. wagnerianus. Don’t even bother getting into what a “form” is verses a “variety”, etc. The fun and silliness of naming things…
One other note:
Trachys are not really grown all that much in the “deep southern States”. One look at gardens and landscapes in cities like New Orleans, Savannah, Orlando, Jacksonville, etc, and you rarely seem them. I guess that because there are so many other palms that grow well there (Sabal, Washingtonia, Queen Palm, Canary Island Dates…etc) maybe they are not used as much. Also, I think I read that’s actually too hot and sunny in the summer in the deep south for Trachys to do well. They seem more common in cool summer climates like the PNW area of the USA, NW Europe, New Zealand,…etc.
I’m going to guess that windmill palms can handle much colder than -12c.the problem with the east coast of the USA is that is can get brutally cold in the winter.they are indeed fairly common in northern coastal Europe but they don’t get anywhere near as cold as the n.e.USA due on the Gulf stream. I’ve seen lots of them in England and am told that some now grow wild in the south west of England. I’d say growing one north of Washington DC best lag the plant with sacking I a very cold winter(like the 2017/18 one!).
I have windmill palms that I planted in 2001. They were maybe 18 inches tall(including the leaves) now they are about 20-25 feet tall. How much longer will they live? I live in Virginia Beach.
Interesting question. There are known ages exceeding 50 years, but the exact age of how long any given tree might live is hard to say. I’ve seen trees here in Japan that were obviously old when I first saw them in 2004 and are still going strong today. Others have perished in that time. Some of these exceeded ~50 feet and must have been quite old already, so 70 years or more seems attainable. That said, many variables can effect growth rates, overall health and longevity. As long as your trees remain relatively disease free, and are otherwise healthy, I don’t see why they can’t live another 30 or more years. Happy growing! Tom
i have 3 windmill palms 12 feet high in new brunswick canada and have never had a problem.
Awesome Mark. Just wondering, are you on the coast? What is the typical minimum temperature at your location? Thanks, Tom
We have several windmills in our yard in Portland, OR. We are at 1000 ft in elevation which means if Portland gets snow, we almost always have it. One winter we had 2 ft of snow for 2 weeks ( a rarity here) with no issues. These trees have been here 22 years. We have had the yellow flowers on most of the trees each year. This year the biggest one put out the large blue-black seeds (it has had the yellow ones before). The seeds have started falling recently due to some high winds. One of my dogs thinks this is a special treat for her. Are these seeds harmful to dogs?
I’ve not heard that any part of this palm is poisonous as such. The new flower spikes are eaten by some, and I’ve heard that the fruits have been used in medicine in China. I would say they mostly likely they won’t hurt your dog unless she goes overboard.
I have 5 trees, one planted in the yard full sun and 4 along the garage, the one in the yard is about 12 feet tall while along the garage are 30 feet, all planted at the same time all same light conditions, I covered the stretch of dirt on the 4tall ones with flat rock like you would cover a patio and the roots stay moist in the Georgia clay soil, I believe this is why they grew so fast in 11 years as the one in the yard does not have rock covering at base of tree.
Interesting David. I can tell you that in Japan they certainly like moist soils, and grow from full sun to deep shade. Tom
I have 6 windmill palms in Atlanta. This year one of them looks like someone took a saw and cut the hairy trunk all the way around the circumference. I have been maintaining the trunk with meticulous annual trimming for years and have never seen anything like it. It’s like the outer bark is peeling off. Is this from an animal? A disease? Please help
Hi Tracy. The leaf bases which make up the fibrous covering over the trunk typically only fall off in very old specimens, so if your tree is fairly young that is unusual. Does the tree look healthy otherwise – growing well, the fronds not yellow, etc? Do you see any fungus or oozing material around the effected area? If not, I wouldn’t worry about it, but do keep an eye on it. It sounds like something mechanically removed the leaf bases – perhaps an animal, or even a person? The biggest issue with these is loss of the growth bud in the crown – that kills palms outright. If your palm seems otherwise healthy, it probably is OK. If it loses vigor, the fronds get smaller, etc. then you may have a problem.
My trachy nainital been growing in
Zone 6 a Woodbury ct since 2005 outdoor and still
Is thriving I do protect it with a
I have a windmill palm that my late husband planted 25 years ago when it was just 2 feet tall. It’s now taller than our second story roof! Hubby passed away 16 years ago, and since then I’ve never fertilized or watered it, just regularly keep the dead fronds trimmed off the trunk. It’s survived snow and wind over the years with no damage at all. I noticed today that alot of the fronds are turning yellow – moreso than the “lower layer” that will normally first turn yellow, then brown as the fronds die off. I live in the PNW, so it gets ample water from the rain, but I’m wondering if I need to be watering it during the summer? Or fertilizing?
Since your palm has been happy for decades now, it seems like something has changed for it to start yellowing like that. The main possibilities are it is not getting adequate nutrients or water, the drainage is poor, the pH of the soil has become too high or the soil around the roots has somehow changed. The point is to think if anything is different this season from previous ones – less water than normal, the soil has become compacted, a contaminant was dumped near it, etc.
You may consider using a slow release pellet type fertilizer with micronutrients, or try dosing it with Epsom salt, but realize you will have to wait to see any change in the new fronds since the old ones will not become green again – that may take a season or two in your cool climate. You can also water it and see if that helps. I wouldn’t worry unless you see it going downhill fast. Good luck with your palm!
Agree with above comment about Windmill palms not planted much in the “deep south” areas of the USA. In the hot subtropical areas from Florida north to North Carolina you don’t see them as much as in temperate areas like the PNW or Europe. Also , north of Long Island/southern Connecticut you don’t see them in New York State or New England, too cold of winters. Windmill is really only a zone 7 or warmer palm (long term).
I have read that there are some plants in NY now. I grew one in my garden in Anchorage (Zone 3) but managed to kill it after its second winter by taking the heavy dry-leaf mulch off of it too early.
“Folks cook up all kinds of novel ways of keep their palms alive in winter including completely wrapping them with fleece or cloth, making miniature greenhouses around the whole tree (sometimes just the crown), protecting the crowns with straw or similar materials, knocking snow off the fronds, mulching the ground around their bases, and even wrapping their trunks with Christmas lights!”
The greengardenguy on YouTube calls this “space station gardening”
One of the problems of trying to really find a “hard line” where Windmill Palms will/will not grow is of course the “microclimate” the palm is in. As many have said, a south-facing, wind sheltered location in zone 7 is really like zone 8 for example. A Windmill might make it against a protected wall in zone 7, but have no chance in the “open”. Additionally, some people consider that a palm can grow in a area if someone grows one even with heavy protection and maybe even “artificial heat”. This is not really realistic – long term. In time protection will end and the palm dies.
My guess, having lived from zone 9 to 6 in the on the East Coast of the USA (Florida to Mass), Windmill palms will generally not survive long below zone 7b for the most part without protection. On the East Coast, the line is somewhere in southern/eastern Virginia/southern Maryland. Right around southern VA, you can find tall, old, long term Windmills that are not protected in any way, and grow long term. North of there, yes there are Windmills growing, but they are “protected”.