Trachycarpus- the Windmill PalmsBy Geoff Stein (palmbob)
July 19, 2008
Probably one of the most useful and hardy of all the palm genera is Trachycarpus. These are solitary fan palms from Asia where some grow happily in regions of high snowfall and cold. Some Trachycarpus are the most cultivated of all the landscape palms as well as being some of the most infamously overcultivated and unsightly species. This is an unfair reputation as individuals that are ugly are usually grown improperly- it is not the fault of the palms themselves as they are quite ornamental and magnificent if given the proper water, soil and climate. This article will cover most of the available Trachycarpus species along with some cultivational recommendations.
Trachycarpus are fan palms with finely and often deeply split leaflets that are held stiffly on the ends of petioles with only the smallest hint of teeth along their margins. These dioecious palms (male or female- not both... with a few rare exceptions) are known for their fiber-covered, relatively narrow trunks and leaves that waver in the winds (sometimes called the windmill palms). They are found from the subtropics of India high into the Himalayas and down into China. The most cold hardy and common of these species (Trachycarpus fortunei) is grown as far north as Scotland, Alaska, the Netherlands etc. and is one of the most cold tolerant of all palms. However a lot of the other less common Trachycarpus species are not nearly as hardy. In general these are primarily temperate palms and do not like tropical climates. However most are not that fond of desert climates, either. That suits me fine as all seem to do great here in Southern California.
Leaf detail of Trachycarpus takil, supposedly; Trachycarpus fortunei with snow Vancouver (photo by Growin); But even Trachycarpus fortunei can suffer cold damage- seedling in third photo in Kansas (Photo by justinmc)
Trachycarpus fortunei, the Chinese Windmill Palm, is the most well known and cultivated species of Trachycarpus. One can find these in every nearly every city and town in California, as well as throughout the southeast in the cooler areas, and all along the western coast up to Canada (and in some Alaskan communities as well). It is also commonly grown all over Europe. For young palms, you need look no further than just about any nursery that sells palms, and this is one of the cheapest species for its size. Getting smaller 5 gal plants is a decent investment as they grow fairly rapidly (one of southern California's fastest growing species... though still horribly slow compared to most palms in the tropics).
Trachycarpus fortuneis- my own seedling; close up of seedling showing fiber (photo by wallaby); and exceptionally tall, older specimens in Los Angeles
Among some palm growing groups this species is unfairly referred to as ‘Trashycarpus'. This is due the frequent occurrence of landscape palms being poorly cultivated and subsequently looking terrible. A well grown Trachycarpus fortunei is a magnificent palm with a full head of leaves and a thick, hairy trunk. These palms like a lot of water and fertilizer. They are commonly used in landscaping because they are cheap, and do tolerate a good deal of abuse and drought... but that does not mean that is how they should be treated. Poorly watered and undernourished palms tend to hold only a meager number of sad, scraggly leaves, often drooping at the tips, and weak, wobbly trunks. Often these palms are only intermittently trimmed so they have a wispy, ragged skirt of dead leaves that only adds to their less-than-tropical look. It is no wonder most palm growers avoid this palm. Treat it well, and you will have a beautiful plant!
Well grown plants in Santa Barbara, California, in private garden showing trunks that have been carefully cleaned of fiber, and in Ohio (I think) at night (photo by tropicsofohio)
Trachycarpus wagnerianus, long considered a separate species, may now be lumped into the Trachycarpus fortunei species but as a dwarf form of it. So it is now called the Dwarf Chinese Windmill Palm, despite it's not having leaves that ‘windmill' in the wind. This poor plant has had a number of identity crises over the years being incorrectly called Trachycarpus takil in the nursery trade for decades. Now, when it appears we finally have that mess cleared up, it is being changed to Trachycarpus fortunei dwarf form. Sigh. Either way, it is another great landscape species and quite different in appearance from Trachycarpus fortunei. This palm has much stiffer, smaller leaves that are less finely split on proportionally shorter petioles. Though a dwarf palm, it still grows up to about 20' tall eventually and is not a super slow grower. Hardiness to both these palms is in the low teens to even down near 5 degrees F. This one seems to take quite a bit of hot sun better than does Trachycarpus fortunei, but both will have burned leaves on super hot days in dry climates.
Trachycarpus wagnerianus in California; last photo shows Trachycarpus wagernianus in foreground with Trachycarpus fortuneis in the background in a park in northern California- you can appreciate the similarties here despite the smaller leaves
Trachycarpus wagnerianus showing typical trunk fiber (typical for Trachycarpus fortunei, too); seedling of Trachycarpus wagnerianus next to seedlings of other Trachycarpus (plant on lower left)
And now Trachycarpus takil may also end up being a form of Trachycarpus fortunei, and not even that different a form. Trachycarpus takil is found in the Himalayas while T fortunei is from China, but the latter is a palm with quite a bit of variation, some individuals which tend to look suspiciously like Trachycarpus takil. But for now I will consider Trachycarpus takil a different species for simplicity sake. This palm does look strikingly like Trachycarpus fortunei, only somewhat larger and with significantly larger leaves. When grown side by side next to Trachycarpus fortuneis these do look different enough to consider as a different species. They are much slower growing, but otherwise similar in cold hardiness (some say even more cold hardy) and cultivational needs. It is, however, a considerably rare plant, and proving one is or is not a Trachycarpus takil really needs a specialist and to have palms old enough to produce flowers (which is the basis really of telling them apart definitively). I have seen seedlings offered as this in nurseries and there is no way I could say for sure they were or were not this species, but I seriously doubt it, unless the seeds could be traced back to being collected in the right country. Supposedly Trachycarpus takils have an offset, assymetrical hastula (the part at the base of the palm leaf where all the leaflets radiate from and where the petiole attaches to the leaf). Also the trunk of this palm tends to be bare of fiber (but often covered with a thick skirt of dead leaves).
Trachycarpus takil in Santa Barbara's Lotusland; and second photo are same palms on left with Trachycarpus fortuneis on right (taller but skinnier with smaller leaf crowns)
Trachycarpus martianus is probably the next most commonly grown species and has been around in the nursery trade about as long as the above-mentioned species. However it is less commonly grown partly due to its rarity, as well as its less adaptable nature in terms of cold hardiness (temps in the mid 20s defoliated my plant, though it did slowly recover). It is an elegant species with little to no fiber on the trunk, and what fiber is present is compactly and tidily kept in place just below the crown. The leaves are quite large and seem too heavy for the thin, scurf-covered petioles as they droop in mature palms. The leaves are completely flat and very evenly and finely split, but a bit less thick and durable looking than those of Trachycarpus fortunei. It is a slow growing palm in any climate, but has some tolerance for the tropics surprisingly, and I saw a nice healthy specimen in Lyons arboretum in Hawaii.
Trachycarpus martianus in California
Trachycarpus martianus living happily in Hawaii (normally thought too tropical for this genus); seedling of mine showing cold damage (other two leaves lost) and new leaf since cold snap
Trachycarpus princeps, or Stone Gate Palm, is rapidly becoming one of the most sought after palms, though still relatively rare (and certainly currently the most sought after species by palm nuts) and also one of the more cold hardy of the Trachycarpus species. I do not know how much cold it can tolerate yet, but my seedling was slightly put off by temps into the mid 20s, and the center spike pulled out that winter (it quickly recovered to my surprise, however). There are two distince Stone Gate Palms from the same area of southern China near Tibet. The more popular, but much slower plant is the classic stiff-leaved form with the white undersides. More recently, another Trachycarpus 'princeps' form, referred to as the green form, or Trachycarpus princeps 'Nova'. Growth wise it is one of the fast species of Trachycarpus and is outpacing all my others of similar age (even Trachycarpus fortunei). However this 'Nova' form does not have the collector's appeal though it still quite an attractive species. My guess is at sometime in the near future, this form will be reclassified as different species. As I mentioned already, the more classic form has unique ‘frosting' on the undersides of the leaves giving them a distinctly blue appearance (accentuated by flash photography if photographed in the evening I have discovered). The leaves are more widely split than in the green form, which are very finely and evenly split. The leaves of both forms are not as flat when young as with other Trachycarpus species and have a slight 'V' to them. From the side the leaves are more ‘cup-shaped' which is unique among Trachycarpus species (in my experience). This cup-shape of the leaves seems to vanish with maturity, however. The trunks of these palms have a thick layer of pale fiber on the trunk (compared to the dark fiber of Trachycarpus fortunei). Young 'Nova' forms are a bit sensitive to hot, inland sun and will burn. Both are gorgeous palms and everyone should be growing them. Currently they are quite costly and still hard to find (particularly the classic 'blue' form), but eventually they should become common (I hope).
Trachycarpus princeps seedling shown wonderful blue-white on leaf undersides (photo by trickshi); maturing 'Nova form' palm in southern California inland
my young Trachycarpus princeps; stem detail
Trachycarpus latisectus (aka Trachycarpus sikkimensis), or the Windamere Palm, is the next most commonly grown species thanks to its recent introduction into the nursery trade. This palm is not only popular because it is easy to grow, but as it is from a more tropical climate in India, is supposedly has more tolerance for tropical cultivation (high heat and or humidity) than do most of the other Trachycarpus (whether this is really true or not I have no idea). It has bright light green leaves that are far less finely split than the other species. It is a slow plant and resents both frosts and hot weather (at least as a seedling), making it a tad less useful a landscape palm in inland southern California where I live. My seedlings were defoliated by frost into the mid 20s, though all recovered slowly. Plants grown in shade were less effected but still are slugs in terms of growth rate. Supposedly mature plants are quite tolerant of heat and have some significant cold hardiness, but I do not know of any mature plants (yet) in California. Only Trachycarpus nana is slower in cultivation.
Trachycarpus latisectus maturing palm in inland southern California very unhappy with the heat; my own seedling fried by summer heat (grow these in partial shade until older); same seedling a year later finally aclimating some
Trachycarpus nanus (or nana- both spellings are in the literature), or Yunnan Dwarf Palm, was a very rare palm until the last 5-10 years when seed became much more available. Now many palm specialty nurseries carry this species. This is a true dwarf species growing a trunk of only 1'-3' over many years, and palms purchased from nurseries that appear to be growing taller than that are certainly suspect. My own seedling is quite slow but in just 3 years already has a rudimentary trunk, making me wonder about its true identity. I will keep you posted, as it is from the same source most other individuals in the nursery trade have been grown from in the last 5 years. Mature palms have blue-green flattened leaves with little or no trunk.
Mature Trachycarpus nanus in southern California, and my own seedling
Trachycarpus oreophilus, the Thai Mountain Fan Palm, is a very rare species in cultivation, but slowly becoming more available. I have only seen one maturing palm and was quite surprised by its elegance and perfection. This could end up being my favorite species. It has the perfectly nearly circular, finely split leaves of most of the other species but with a very neat, tightly woven matte of fiber on its trunk that is highly ornamental. Petioles are stiff and covered with an attractive scurf. Cold hardiness is totally unknown for this plant (so far) but I am hopeful it will be a good one for most climates. As the name suggests, this palm is from Thailand (in the northern mountains).
Trachycarpus oreophilus maturing palm inland southern California (seems to tolerate heat great); close up of weave on trunk; scurfy, almost wooly petioles
There are several other Trachycarpus species: Trachycarpus geminisectus, and an un-named species from Manipur near the Indian border of Burma, that are still pretty rare in cultivation. I have a single leaf seedling of the former, but I suspect it will be years before I will be able to tell you anything useful about this species other than it has been given the common name Eight Peaks Fan Palm (I cannot tell you why) from Viet Nam. This is another species with some degree of white under the leaves and will undoubtedly be a popular one once the few seedlings out there begin maturing.