My Hardy Palms: Trials, Tribulations & Triumphs
Practical? You want practical? In this painstakingly
written article Robert shares with us his hopes, dreams and techniques
of growing hardy palms in Austria. Practical it is!
Robert Lackner, Feldgasse 48, Bad Deutsch Altenburg, Austria
Chamaerops No.21, Winter Edition 95/96
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Left: Snow fun for an Austrian Trachy
Right: Summer and Winter in Austria
Due to the good response I received following my article
in Chamaerops' summer issue (Palms in Austria) I've been encouraged
by our editor to write a follow-up for the magazine. Normally I
wouldn't have done this before next spring or summer, but there
was one thing that forced me to put hands on the keyboard again,
namely: the worst winter we have been experiencing in a long time.
Biting snowstorms, long periods of sometimes severe frost and lots
of snow have been ruling most of the winter so far over the past
10 weeks, not only in northern Europe, which has just been going
through one of its most severe winters for a long time, but also
here in Austria's flatland areas. Additionally this ice-cold winter
weather coincides with a couple of palm experiments I've been conducting,
which give further proof of what some palms really can cope with.
So far the experiments have been successful, albeit winter is not
over yet, but at least the cold has loosened its wrathful grip now
for a while. Yet winter is only lessened for a short time, because
the weather forecast promises severe night-frosts for next week
again. I yearn for a warm February like last year when +15°C
to +20°C in the shade were quite common throughout the whole
month, because that is when we usually unwrap all the sheltered
palms. After a few hours' work the garden once again resembles a
tropical paradise...
But first of all I'd like to take this opportunity
of telling you how I became interested in palms generally. When
I was a young boy my parents took me every summer to Tyrol, Austria's
westernmost-but-one province. Most of the time we were hiking up
in the mountains, but as Tyrol's weather is not stable throughout
the summer we had to suffer some pretty chilly and rainy weather
sometimes. Even in the summer, temperatures can drop below 10°C
there and snowfall down to 1500m is also not unknown at this time
of the year. When such rain fronts moved in to Tyrol we usually
headed for South Tyrol. Italy's northernmost province was until
1921 part of Tyrol and thus of Austria and in fact its people and
landscape remind the visitor of the alpine regions of western Austria.
But there is also something that tells you that you're in Italy,
namely: palms. Many parts of this region are protected by mighty
mountains from the cool arctic fronts that move in from northern
Europe. Only the mild air moving up from the south can flow in unhindered.
Driving from Tyrol on a wet and cold summer day to South Tyrol gives
you the impression of entering a whole new world. Though only some
60 km (as the crow flies) separate Meran (in South Tyrol) from Innsbruck
(in Tyrol), their climates seems to be separated by 500 km. 120
cloudless days per year, no fog at all and an annual winter temperature
of more than 12°C make Meran a very special place at this latitude.
Places at the same latitude in southern Austria are much cooler
by comparison especially in winter. When you pass the mountains
at the border and drive down to Meran you could almost believe you're
somewhere in Paradise.
Only a few kilometres before, you've passed the glaciers
of some of the highest mountains in Austria and then you dive into
a subtropical jungle with palms, huge fig trees, oranges and many
other exotic plants. Looking a bit closer in some places I could
even spot some Phoenix canariensis and Cycas revoluta, though most
of the palms planted there are Trachycarpus fortunei. The Trachys
I had seen there are amongst the most beautiful ones I know, as
the lack of wind and lots of sunshine contribute to their well-being.
It was not only the mere presence of those palms that fascinated
me so much but rather the extreme contrast between the alpine vegetation,
the enormous mountains (between 2500m and 3900m) and the subtropical
plants.
By this time I believed that Meman's exotic vegetation
was explained by its extremely mild climate. You can imagine that
I was somehow puzzled when in 1986 I spent some days in Meran again
and an elderly man told me that during the past winter they had
had some -18°C there. 'How can that be?', I asked myself. 'How
can those palms and all that stuff they grow around here look so
healthy and thrive so well ? No, it can't be. We hardly get -18°C
back home and we don't have any palms there!' I considered this
innocent elderly man to be a bit mentally deranged but as I was
not absolutely sure about this I had to make some investigations.
The rest is history. When I found out that it was indeed true I
vowed that I'd also grow palms back home in Austria. Some years
later - also in Meran - I came across the hardy banana Musa basjoo
for the first time and again I couldn't believe it. 'No don't start
that again', I thought, 'palms yes, OK, but bananas ? No, never,
it simply can't be. This is probably just some fake, it must be
dug in with a tub or whatever. A banana can't thrive in a climate
where once -18°C occurred even if this was an exception. Every
child knows that bananas grow in the tropics' . I was wrong again,
just how, I found out many years later. So that's how the whole
costly matter began and since then I've been collecting and planting
a frightening number of palms, bananas and whatsoever else I could
get hold of.
Now I want to tell you something about the aforementioned
palm-experiments. This year's weather was really weird in many ways.
Precipitation much above normal, a cool spring, a hot and completely
dry summer and a rainless and very warm October with more than four
weeks of unbroken sunshine, and temperatures of sometimes more than
27°C were followed by an unseasonably early snowfall in the
first week of November. The first three weeks of December were mostly
around zero with more snow again. But then it began. Three exceptionally
mild days at Christmas with 15°C and then again a heavy snowfall
only this time the temperature dropped rapidly and did not stop
until it reached -14°C. Even during the day the mercury didn't
climb higher than -9°C to 4°C. A couple of nights followed
with temperatures below -10°C again. The whole frost period
lasted from December 26th to January 7th. Worst of all was the snowdrift
that within some hours caused the traffic to break down completely
in some areas of eastern Austria. Snowdrifts reached staggering
heights of between 2 and 4m. Incredible! Arterial roads had to be
closed for two days because the snow-ploughs couldn't cope with
the masses of snow any more.
Believe me I was not too enthusiastic that the worst
winter for many years coincided with the palm experiments I'd started.
These trials meant I should leave some of my palms outside unprotected
-during the whole winter. The species in question were: a 20 - 30cm
high Rhapidophyllum hystrix, a Trachycarpus fortunei 40 cm high
(this special Trachy showed clear signs of interbreeding with its
hardier relative T. takil, it was that which made me buy it), and
two Trachys with trunk heights between 30 and 50 cm. There are two
facts to mention, namely that I cleared away all the snow from the
palms so that they were not protected by it and for the first time
I measured the temperature right at the palms' fans. I did this
at the T. fortunei/takil at its fan height, i.e. about 30 cm above
the ground. And what I found out there was really a surprise to
me. The temperature near the ground was 3-4°C lower than 2m
above the surface. The maximum-minimum thermometer showed clearly
that this little poor Trachy had had to withstand -17°C unprotected.
Considering this I expected all the Trachys to wilt. Especially
the fans of one of them looked extremely poor, they were very dark
green and somehow folded. You can imagine I was rather bewildered
when after the first thaw the leaves unfolded again and looked like
nothing has happened. Even after a couple of rather warm days no
damages except a light tip-burn affecting a few leaves was visible.
The little Trachy was the only one that suffered some real damage
as about 50% of its fans were heavily damaged though not dead, the
rest of them were unharmed. The largest of those three was completely
undamaged and had no tip-burn at all. Perhaps this may be due to
the fact that its leaves are higher above the ground than those
of the other Trachys and therefore the temperature was 3 or 4°C
higher. No need to mention that the Rhapidophyllum hystrix was also
not harmed. Indeed it may have laughed at those -17°C temperatures.
Also part of the experiment were two Sabal minor which
also remained outside unsheltered. It turned out that the leaves
that had already began to turn slightly yellow during the hot summer
became brown, whereas the green ones kept their good shape. A Trachycarpus
takil seedling I planted out in October (not really a good time)
was also hardly touched by the heavy frosts, though I have to admit
it was protected during the most severe frost by means of a snow
heap. A couple of rather big Trachycarpus fortunei (the largest
about 3 m, trunks between 1m and l.80m) also stay outside and are
protected by some straw on the ground and a blanket wrapped around
the leaves. The abovesaid experiments tell me even this shelter
is not necessary. I'm somehow astonished that reports from the southern
parts of the USA show that Trachys were killed or damaged there
at sometimes much milder temperatures. In my opinion this can only
lead to the conclusion that the palms reduce the frost resistance
after a series of warm winters. Especially in the south-east of
the States mild winters are the norm, albeit once in a while arctic
air is sent down sometimes even to Florida. Normally they don't
have to cope with low temperatures and once they occur they're not
really 'prepared', whereas here in eastern Austria cold and cool
winters occur quite often, i.e. at least a certain period of every
winter is cold.
This year my largest Trachy, which is a female plant,
produced its first fruits and I really have to say quite a bunch
of them. I really was excited by this event as it was the first
year where male and female plants bloomed together. What is a bit
of a surprise to me is the time when the Trachys begin to put out
their new blooms. The yellow tips become already visible in December.
Last winter I attributed this to the extremely mild weather but
this is clearly not so this year. Some other plants that remained
in the open ground unprotected were Magnolia grandiflora, Cupressus
sempervirens and many yuccas such as two Yucca aloifolia variegata
and Yucca gloriosa What I found out about those two yuccas species
is that they seems to take a lot more frost than previously assumed.
I have definite proof that Yucca gloriosa grows in some areas in
Austria where the night-temperatures drop almost every winter to
-20°C and below. That would also explain why some really large
Yucca gloriosa grow in my area despite the disastrous winter of
1985 where -22°C in my area was recorded in some places and
only a few kilometres away, even -27°C. The yuccas are still
there and were never protected. Also the Yucca aloifolia 'variegata'
in my garden showed not the slightest sign of stress at -18°C
and I truly believe they can also cope with temperatures of at least
-20°C. Indeed in northern Italy I purchased a Yucca aloifolia
and the gardener there told me that -20°C wouldn't be a problem
for this plant. I think he knew what he was talking about as especially
northern Italy was also struck by the winter of 1985.
In my last article I promised to tell you more about
my then recently-planted palms. The results were quite interesting.
Even my Rhapidophyllum hystrix achieved a satisfactory growth rate.
In its first summer it threw up three new leaves though it is a
very small plant and has only one stem'. Encouraged by this, last
autumn I bought two large clumps of Rhapidophyllum about 150 cm
high with a couple of trunks each. One is a female plant, the other
a male one and the female plant has already ripe fruits. I think
these large plants will produce - once established - a quite good
number of leaves a year, but of course not nearly as many as my
Trachys, which now throw up 15 fans a year and whose trunks increase
by a foot in the same time. But of course they (the Rhapidos) are
so extremely hardy they should even survive disaster winters without
protection, whereas I'm not so certain about this with Trachycarpus
fortunei, though I again received a report where a Trachy survived
-20°C unprotected (by accident) . You can't really expect it
will keep its leaves at those temperatures but if a plant produces
10 to 15 new ones in a year this is not a tragedy.
The Nannorrhops ritchieana are worthy of a mention
here. Probably the most obvious fact for me was that the green Nanny
is undoubtedly hardier and especially more resistant against bugs
than its blue counterpart. I had a blue and a green Nannorrhops
in the open ground. As I planted them in early March, and last year's
spring was very wet and cold they had to endure some severe weather.
The green one survived; the blue one wilted. Admittedly a friend
of mine also grows a blue Nanny outside but he planted it much later
and he protects it with straw during most of the winter. His one
still thrives. Another fact is that the second blue Nanny I have
was heavily damaged by just 2 hours of -11°C to maybe (above
the snow-surface) -14°C. Its leaves wilted only a couple of
hours later (the tub was covered with snow). The reason why I was
forced to put it outside during those temperatures was that it was
heavily attacked by bugs which I couldn't get rid of even with a
few degrees below zero outside. Also a fact is that a pot-grown
green Nannorrhops that was placed just beside the blue one all the
time was not affected by the bug attack. Apart from that, the green
one planted outside withstood the heavy frost unharmed. The speed
of growth of both forms was really good considering that these are
still quite small plants (30 cm high). The green one in the open
ground threw up 2 new leaves and to my astonishment the one in the
tub four. But this was no match for the blue form (in a tub also)
which threw up 6 new fans. This is outside, not in the greenhouse!
So especially considering the speed of growth the blue form is indeed
very interesting and I think the last words about its tenderness
are not yet spoken. There are too many uncertain factors as humidity
and the weakening due to the bugs, though there is no doubt that
the green form is tougher, but on the other hand also slower growing.
Evidently - at least from my point of view - plants that are raised
in heated greenhouses are more feeble than their counterparts being
brought up outside, but it is certainly a problem to grow plants
below a certain size outside.
Serenoa repens plays in the same league as Nannorrhops
and Rhapidophyllum and thus unfolded 3 new fans at each stem. This
plant is also some 30 - 40 cm high. Undoubtedly the slowest grower
of all was Sabal minor which only produced one new fan. Admittedly
I had to replant it twice because of certain circumstances but even
so, the growth rate was really slow. Once settled in it may produce
3 - 4 or 5 fans in later years but I don't think I can expect more.
But the Sabal minor did have one big surprise for me. One of the
Sabal's heart rotted away and I pulled it out. There was nothing
left except a big empty hole in the middle. I wanted to throw it
away, but fortunately I didn't. Only some 3 weeks later a new fan
began to move up. So don't give a Sabal minor up for dead too soon
especially as its growth point lies below the surface. This special
characteristic also enables this palm to survive incredible low
temperatures down to -30°C at least according to an article
in the 'Hardy Palm International' where it was reported that Sabal
minor in Tennessee survived -24°F(-29°C). Of course the
palms were completely defoliated. What was also mentioned there
was that the fans of Rhapidophyllum hystrix can survive -24°C
without damage and they must know what they are talking about because
the south-east of the States is this hardy palm's habitat, Even
the small plants or shall I say seedlings of Trachycarpus takil
grew very fast and threw up 6 leaves on average and the faster ones
even eight. I have now 11 T. takil seedlings and I want to buy a
lot more in spring and try to raise them outside together with a
lot of Chamaerops humilis var. cerifera' and Trachycarpus sikkimensis
seedlings. Hopefully the blue Chamaerops will be a little hardier
than its green and blue-green relatives as it grows in cooler locations
and has to tolerate quite severe winter weather. I know that in
the UK Chamaerops is quite hardy but even here in the mildest regions
of Austria I wouldn't dare plant one out. Not so with the blue ones
as they might even reach the hardiness of Trachycarpus fortunei.
We will see what the future brings. It would be an ideal palm especially
in very windy places as it tolerates stronger winds than a Trachy.
Just a word now about the toughness of T. takil. As
even T. fortunei withstands -17°C here at my home without or
with only minor damage I suppose that a T. fortunei with a blanket
wrapped around it and with the roots sheltered would survive at
least -20°C or maybe more (at this point luck becomes an important
factor) . Therefore I assume that T. takil would be undamaged down
to -l8° or -20°C and survive even much lower temperatures.
But who knows if it will ever become that cold again in our lifetime
as winters like 1985 occur only every 50 years normally.
Another extremely worthy addition to my palm collection
this autumn were two rather large Jubaea chilensis. Not really cheap
admittedly but worth every penny. They are about 80 cm in height,
but how strong and healthy they look. Wow!! Even a heavy snowfall
couldn't harm their leaves when I left them outside in November.
They will be planted in the open ground in about a month together
with the new large Rhapidophyllums. Good news I also heard from
Tobias Spanner about their frost-tolerance. He expects them to be
as hardy as Trachycarpus fortunei and told me that in France they
survived almost -20°C undamaged. Of course small plants are
not that tough in the first years, but they shouldn't have any trouble
with -12°C, maybe -15°C. Jubaea was always considered to
be the slowest growing of all palm trees, but when planted out it
can achieve a quite moderate growth rate. The problem is that it
slows down its growth when you leave it in a pot as soon as the
roots reach the bottom. Its roots should not be hindered, and allowed
to develop freely. Jubaea can well cope with moisture, drought,
snow, strong winds, and grows also in cooler climates happily and
therefore is really an excellent palm for a variety of climates.
Besides, it's really impressive and very different from a Trachy.
It's probably the only really hardy feather-leaved palm.
The Musa basjoos I planted grew extremely fast. They
really shoot up to the sky. I bought a couple of them from Tobias
and we had to saw them off in the middle in order to fit them in
the car. After 5 hours' drive they had already grown between 5 and
10 cm out of where they were sawn off, despite they had no soil
and no water at their base because they were not pot grown and therefore
had to be dug out. But one important fact I found out about the
Musa basjoo, namely too much water does not contribute to their
well-being. I watered some of them 3 times a day and this seems
to have led to a complete standstill in growth. Watering them once
on a hot summer day was enough and they had no problems when they
had no water for some days and continued growing as strongly as
ever. In the 'Hardy Palm International' also some hardy edible bananas
were mentioned which endured -16°C unprotected. Can that be
true? Why not, I won't be surprised by a single exotic hardy plant
any more. I've learned my Meran-lessons. What happened to the supposedly
hardy banana our editor mentioned once briefly in his Asia diary
(issue 18, 29th October)?
There is one more thing I have to mention, because
it was the most incredible palm-thing that happened to me this winter.
Together with the blue Nannorrhops I mentioned before I also put
outside a Brahea armata seedling, which was also heavily attacked
by bugs. There was nothing to lose any more and so I took the risk.
The only thing I had to lose was a bug eaten seedling, not a 20m
Jubaea. Of course I didn't expect it to survive, but it turned out
that it was not even damaged by 2 hours of -11°C to -14°C.
Then I left it outside for over a day in permanent frost and it
was still not harmed. Now I look with more appreciation at this
Brahea armata seedling.
Unfortunately I've lost the Butia capitata I mentioned
in my last article but not due to frost but due to root rot. What
I didn't know was that below the surface a clay layer prevented
the water from running off and that caused the whole nuisance. The
frost itself didn't harm this palm as until May there were no signs
of damage visible and it thrived very well. I guess the combination
of the clay-layer problem and the abnormally high precipitation
it received last spring were fatal for this palm. Well, failures
are also part of our hobby.
The palms in the front garden I planted just a week
after my first article (I mentioned them briefly) really serve to
spread the word about palms because many people stop to watch what
the hell this is and also some of them ask me if they are also able
to plant palms in their own garden. Especially now in the midst
of the winter some people incredulously rub their eyes when they
pass by at some -10°C or maybe even less. This can really stretch
your mind when you see it for the first time.
Well, that's the Story So Far. Many other parts of
Europe are having a pretty bad winter and I'm sure a lot of interesting
stories are awaiting us. You just have to write them.
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