 Nannorrhops, The Enigmatic Palm
by Robert Lackner, Burggasse 1a, 2405 Bad Deutschaltenburg, Austria
Chamaerops No. 45, published online 29-01-2003
[an error occurred while processing the directive]
 
 
 
From left to right:
- A massive "green" Nannorrhops at Fairchild Tropical Garden, Miami. Photo: Gibbons/Spanner.
- Some like it hot: a "green" Nannorrhops ritchiana in the desert in the mountains north of Sibi,
Pakistan. Photo: Gibbons/Spanner.
- Green Pakistan form. This plant has withstood -9°C outside in the pot during the last winter without problems.
- Silver Pakistan form, green Pakistan form, silver Iran form with intense silver fans, silver Iran form with
green-blue-yellish fans.
- Costapalmate fans of the silver Pakistan form.
- Palmate fans of the green Pakistan form.
- Trunk with ornage fur, green Pakistan form.
Photos: Robert Lackner
When your interest in palms was awakened it was almost certainly caused by one of the many Trachys,
by a Phoenix, or Washingtonia, all of which can be seen frequently in milder and sometimes even cooler parts
of Europe. Then you learn and read more about several other species, some of which can also be grown under really
harsh conditions, be it frost, drought, or heat. After a while you'll find a really good palm book and when
flying over the pages you'll almost certainly make a pause at the page of Nannorrhops ritchiana, the Mazari
Palm or, as it should be called, the Enigmatic Palm. You want to know why this palm is a mystery in my eyes?
Well there are many good reasons:
Enigma No. 1
This palm is so common and abundant in its habitat and yet so few plants can be found in cultivation.
On one hand everybody talks about it, but on the other hand only a few people grow these palms successfully.
Enigma No. 2
Also adding to its mystery are the areas where this palm grows. The deserts of Afghanistan,
Pakistan and Iran are not on most people's lists for their family holidays, and even if they were, the current
situation makes it even more difficult to visit these places than it was a year or so ago. Thus, only a few
palm enthusiasts have seen this palm in habitat. This, in my opinion, has allowed many rumors about its climatic
growing conditions to arise, especially in the beginning. I possess four palm books where this mysterious palm
(which is named after its original collector David Ritchie) is mentioned. Three of these books claim that these
plants may be covered with snow for long periods during the winter. One book even mentions that it is covered
with snow for months at a time. Climatic data on these areas indeed suggest that it can become really cold in
some places where Nannorrhops grows, as far as the absolute extreme minimum temperature is concerned. This,
however, only applies to some of Nannorrhops' habitats, not to all of them. The climatic data also show that
these areas have a fairly high mean annual temperature and almost no precipitation. This suggests that the plants
are normally not covered with snow for weeks or months because it rarely snows there, and if it does, the snow
certainly melts soon in the warm desert sun of these southern regions. This brings us to the next enigma, and
the question of how hardy this palm really is.
Enigma No. 3
All of the above mentioned palm books state that this is an "extremely cold-tolerant palm",
which is a relative term, because you don't know from which (geographical) point of view this was written. Two
books are even more precise, suggesting it can tolerate temperatures as low as -20°C or even -26°C.
This is certainly a point which almost forces the inexperienced palm enthusiast to purchase this palm at any
price, because in his day dreams he already sees a nice palm with its fan leaves swaying outside in a gentle
arctic breeze at -25°C. I, too, thought "I must have this one" some eight or nine years ago when
I first ran across the Mazari Palm’s description. In addition, many plant nurseries offer this as a palm
that is hardy in many parts of central Europe. But is this really the case? Fact is, that hardly any Nannies
are growing successfully outside in central Europe and you can read more about failures than about successes.
Even in relatively mild areas, such as southern England, this hardy palm does not seem to grow satisfactorily.
So what is true and what is not?
As for most exotic plants, this question does not have a straight answer. Nannorrhops ritchiana is indeed a
very frost-tolerant palm in habitat, but the frosts there are very dry and, compared with central and western
Europe, short lived. Many parts of Central and Western Europe, however, are rather moist and humid, especially
during the critical winter months. This, in my opinion, makes this palm unsuitable for outdoor cultivation in
many areas, unless you can create a good shelter to keep the plant completely dry while also allowing it to
get enough light, as this palm requires bright conditions even during the winter. Furthermore, Nannorrhops requires
very good drainage. It is odd that in England so many rather tender (which again is a relative term) palms can
be grown without shelter (e.g. Phoenix, Arenga engleri), but the allegedly extremely frost-hardy Nannorrhops
simply rots away and dies, unless of course it has either a very favourable and/or dry place.
In light of all this, I strongly disagree with nurseries selling this palm as being hardy in almost all parts
of central and western Europe. If this palm can be grown in the cooler parts of Europe, then in my opinion more
continental areas with cold, dry winters and hot summers have the best theoretical chances for outdoor cultivation,
unless their winters are too cold for this palm to grow. That means that without special preparations this is
not the ideal palm for countries that have mild but moist winters (e.g. England, the Netherlands, Belgium, the
northwest of France and the northern parts of Germany). This palm would probably be better suited to Hungary,
Slovenia, Croatia, Slovakia and maybe eastern Austria. But even in these parts a rain-sheltered place, good
drainage andÑduring severe coldÑsome frost protection is certainly necessary. (I need not mention
that Nannorrhops has no problems growing in southern Europe, and therefore I hope you don't mind if I focus
on the less favourable regions of Europe).
Regarding Nannorrhops' frost hardiness you should take into consideration that Washingtonia filifera is, in
the Southwest of the States, regarded as being hardier than Trachycarpus. The reason is clear: Trachys are certainly
not suited to desert climates and thus won't grow very well there. W. filifera, however, is really exceedingly
hardy in such dry climates and can therefore indeed cope with -20°C for short periods. W. filifera is cultivated
in areas (e.g. El Paso, Texas or St. George, Utah) where -20°C can be reached (although it does so very
rarely), and where frosts down to -10°C are fairly common. But the frosts there are dry and short lived,
which makes a huge difference. In central and western Europe, on the other hand, W. filifera (if you have the
true type; many Washingtonias being offered as W. filifera are actually W. robusta) is rather difficult, because
it needs fresh air and resents moisture, especially during the winter, and is therefore sometimes damaged at
temperatures around -5ÁC. Again, the lower the humidity, the more cold it tolerates. W. robusta, although
in habitat not nearly as frost tolerant as W. filifera, copes much better with moisture and is therefore better
suited to our gardens and greenhouses. So you see, if a palm can cope with -20ÁC in a certain climate,
this must not lead to the conclusion that it can be planted out in central Europe.
There's one thing my experience with Nannorrhops shows clearly: It is certainly better suited to our winters
than Washingtonia filifera and thus it is certainly hardier. During the winter 95/96 I wintered a blue and a
green Nanny seedling outside just with a plastic pot placed over it for rain protection. That winter was the
longest and wettest winter I can recall (see my article in Chamaerops No. 30) with an absolute minimum of -19°C.
The green Nanny seedling just survived the winter and began to recover later, but very slowly. The blue Nannorrhops
died. Formerly I was too inexperienced and thus too impatient and wanted to plant them out as soon as possible.
Now I know that it makes no sense to plant out seedlings of any palm, let alone of a palm that needs much heat
to achieve a good growth rate. I therefore dug up the surviving green Nanny and placed it in a pot again.
Enigma No. 4
As I mentioned before, there are Nannies with different leaf colours, which leads me to the
next mystery: different species. It is still unclear if all the different forms of Nannorrhops can be lumped
together into just one species. Formerly four species of Nannorrhops were recognized: N. ritchiana, N. stocksiana,
N. arabica and N. naudiniana. H. Moore lumped them into just one variable species, namely Nannorrhops ritchiana.
Now, doubts from experts arise, suggesting that some of the different forms found in habitat may indeed be separate
species.
I can attest that the three forms I have look quite different from one another. I have the green form from Pakistan,
the blue Pakistan form (also offered as 'Silver form'), and a silver form from Iran (sometimes referred to as
N. arabica or N. sp. 'Iran'). It seems that the Pakistan silver form is by far the least hardy, which was also
my experience, whereas the Pakistan green form and the Iran silver form seem to be hardier. The most obvious
difference between the forms is their leaf colour, which ranges from an intense silver-white (Iran form), to
a moderate silver-blue (silver Pakistan form), to plain green with bluish undersides (green Pakistan form).
The varying amount of insect pests these plants attract also suggests there are differences between the forms.
The green form is obviously the least tasty as I have hardly ever seen any insect pests on its leaves. The Iran
form suffers only slightly, whereas the Pakistan silver form is sometimes moderately attacked by pests. The
leaf bases of my three forms are also different. The green form is partly covered with an orange fur that can
be seen easily. The Iran form shows only a very light orange-brown fur, whereas the Pakistan silver form completely
lacks this characteristic. Another distinguishing characteristic is the leaf form. The silver forms from Iran
and Pakistan have costapalmate leaves, whereas the green Nanny has palmate ones. Taking all of this into consideration,
one can see that my experience supports the theory that not all of the former Nannorrhops species should have
been lumped together into just one, but of course more scientific proof and detailed examinations are neededÑsuch
as examining the flowering characteristics of these palmsÑbefore any solid conclusions can be made. Unfortunately,
the necessary plant materials appear to be hard to come by, so it'll still be a while before we palm enthusiasts
are better informed about Nannorrhops' scientific status.
As you can see, 'Enigmatic Palm' is really an appropriate title for Nannorrhops. It is certainlyÑespecially
in the cooler regions of the worldÑone of the most talked about palms, and despite that, so little is
known about it. And what's more, some of the information given is simply wrong. This has led to the creation
of legendary myths about the palm from the deserts of Afghanistan, Pakistan, and Iran. Hopefully these myths
will give way to more reliable and scientific information that will certainly save the lives of many Nannies
that would otherwise just rot away or barely grow in many of the colder regions of Europe.
Reading this article you might suppose that I want to convince you to leave Nannorrhops to the experts or for
warmer climates. No, definitely not! I encourage you, in fact, to buy one or raise one from seed, but give it
the growing conditions it needs. I have been experimenting with Nannorrhops for seven or eight years and I can
assure you it's really a marvelous palm.
Enigma No. 5
Another myth about Nannorrhops is that it is a slow-growing palm. It is just slow growing when
given the wrong conditions! If you know how to raise them, however, you can have a splendid looking palm within
only a few years. I purchased my green (Pakistan) Nanny as a 30 cm (1 ft.) seedling, still with seedling leaves.
Now, not even six years later, I have a wonderful double trunked palm with a height of almost 150 cm (5 ft.)
without the pot. The trunk diameter at the base of the taller stem is already 12-13 cm and it is still growing
fast. Even much faster growing is my silver form from Iran. I raised it from seed three and a half years ago.
Now it measures 100 cm in height!! Doesn't really sound like a slow growing palm, does it?
So what is the proper way to raise them?
• Use large pots.
• Keep them very hot (30 - 45°C).
• Keep them very moist during the hottest temperatures.
• Use (plastic) saucers during this time, so that the plants can stand in water.
• Allow them to soak up the water from the saucers before refilling them.
• Reduce the watering as it becomes cooler. The lower the temperature, the less water they need.
• Keep them very dry in winter if they are in an unheated greenhouse. If you keep Nannorrhops in a heated
greenhouse do continue watering, but not as excessively as during the hot summer months.
Germination
I germinate Nannorrhops seed like any other palm, in a transparent plastic bag, but with two
little differences: 1) I keep the seeds at temperatures between 30 and 45°C as these hot temperatures are
necessary for good results; and 2) I take the seedlings out at an earlier stage than I would for Trachycarpus,
for example. When germinating Trachycarpus it does not make a big difference if you leave the plants somewhat
longer inside the plastic bag. Nannorrhops, however, seems to bring slightly better results if you take them
out and pot them up a little bit earlier, because of their strong root growth. I usually take them out when
the first seedling leaf has just begun to appear. Then I plant it in a deep plastic pot to allow the first roots
to grow unhindered for a while. Leaving the plantlets inside the plastic bag longer means that the roots of
the seedlings get mixed up and the necessary separation of the plants afterwards causes some stress. Therefore
it's better to pot them up while the roots are still small.
The first seedlings usually appear after three to six weeks. As far as the silver forms are concerned most of
the seeds germinate within two months. I achieved a germination rate of 85 to 90% with both silver forms. The
green form seems to germinate over a longer period. Some seeds can take over a year to sprout, some only a few
weeks after sowing. But generally they also germinate satisfactorily.
Soil
I do not use any special type of soil. Nannorrhops seems to grow equally well in regular garden
mold or soil for pot plants. To my surprise, however, they did grow much more slowly in sandy soil. While they
grew nicely even in this sandy soil, the plants that had been growing in light soil types grew much faster.
I also fertilize the Nannies like any other pot plant. As such, my treatment of Nannorrhops, Washingtonia, or
Trachycarpus is the same, except that I keep them at different temperatures during the growing season.
Conclusion
All of the different types of Nannorrhops are wonderful plants. They are exceptionally good
palms for the heated and unheated greenhouse and almost trouble free. The green form especially is completely
trouble free, as I have never, ever had any problems with pests and diseases, despite the fact that this plant
was, until last month, in the greenhouse year round. During the first three years I kept it in an unheated greenhouse
and afterwards it remained two years inside a heated one, where it grew side-by-side with a superb coconut palm.
Would you believe that these two palms thrive under identical conditions? The Iran silver form is a must because
of its beautiful colour, and it is nearly as trouble free as the green Pakistan form, in heated greenhouses
as well as in unheated ones. The Pakistan silver form is probably the most 'tender' of my Nannies. If you keep
it permanently in a greenhouse you'll surely fight sometimes against some insect pests, but that has never been
a big problem. It is also an interesting palm because of its beautifully coloured leaves.
During the last summer the green Nanny became too broad to be kept in my rather small greenhouse, so I decided
that IÔd plant it out next year. Since then I have been keeping it outside in the pot, so that it gets
used to the colder temperatures outside. I'll leave it outside as long as temperatures do not fall below -8
or -9°C, and then winter it in a cool place. Next spring I'll plant it out in the hottest and driest position
I have in my garden. I feel it has a good chance in our climate in this favourable spot, as it would be completely
rain sheltered and would see sun from dawn till dusk. Our hot continental summers will do the rest and our normally
very dry winters will hopefully be dry enough.
During the last four winters we didn't see much snow here and temperatures never fell below -10°C. The summers
were very long, hot, and very dry, which caused tremendous havoc agriculturally. To such conditions Nannorrhops
would be ideally suited. However, I have no illusions that some really cold winters will come; it's just a matter
of time. When it does become really cold (-20°C) again some winter (which happens about every 15 years or
so), I'll be prepared to help the green Nanny through the worst of the cold.
If the green Nannorrhops grows satisfactorily during the next two or three years, then the silver Iran form
will be the next to be planted out, as it'll be quite large then. According to their habitat, these two Nanny
forms are hardy enough to tolerate temperatures of -20°C in dry conditions. I'll see how they cope with
the not-so-cold but rather foggy periods here, which can also occur during the winter. This is probably the
only drawback of our climate as far as Nannorrhops' needs are concerned. Newer palm literature suggests, and
my experience shows, that the silver Pakistan form is certainly the least hardy in terms of low temperatures.
So this palm is, in my opinion, not suitable for outdoor cultivation in my area.
If you want to see some nice, mature Nannorrhops, you can find them at the Rome Botanic Gardens. Probably the
best known, this green Nanny has a huge winding trunk. The most beautiful Nannies I have seen grow in the garden
of Villa Thuret in Cap d'Antibes in the South of France. There you can admire a beautiful double trunked and
upright green Nanny about 3 m in height, and, beside it, a somewhat smaller plant. I also saw plants in Huntington
Garden in California, and I've heard of large plants in the Fairchild Botanical Garden in Florida and of one
in a private garden in Florence.
The bottom line is that, if you can offer Nannorrhops the appropriate conditions, you should get one as soon
as possible. You wont regret it! Although Nannorrhops will still remain somewhat of a mystery until experts
do further examinations, I hope that I have given you a brief insight into this wonderful palm that might help
you to grow them successfully. I'm not an expert as far as the classification of palms into their species is
concerned, and therefore I don't know whether my observations of the characteristics of the different forms
are useful or not, but I'm eager to know what will happen with the Enigmatic Palm in the future.
Readers Comments:
(No comments yet. Be the first to add a comment to
this article!)
|
 |
[an error occurred while processing the directive] |
