The Wheat and the Chaff

Another visit to Austrian member Robert Lackner's garden, full of practical information, and first hand knowledge.
Robert Lackner, 2405 Bad Deutsch Altenburg, Feldstrasse 48, Austria
Chamaerops No.30 Spring 1998

A Long Way From Home: Washingtonia robusta in Robert's garden in Austria.

‘Have a mild winter folks’, I wished you at the end of my last article (Chamaerops, Autumn 96). Well probably the Eskimos had one or the people in Brazil. I guess neither were in need of one, admittedly for different reasons though. What can be worse than a bad winter, my dear palm fellows? Right, two bad winters. Last time I reported about one of the coldest and longest winters in eastern Austria this century. The winter 1995/96 was certainly a record winter in terms of snowfall and frost duration. Temperatures fell as low as -19 deg. C, but surprisingly it turned out this was not the limit for my at-this-time unprotected Trachycarpus.

Well what about it, I thought, bad winters have always occurred around here. Damage was appraised and new palm replantings made as everyone was absolutely certain that the winter 95/96 was an exception and no two such winters can occur in a row. In the beginning of the winter 96/97 this seemed to be right. November was just fabulous! Most of the days were warm enough to wear T-shirts, the warmest temperature was +23 deg. C in the shade and I was able to have breakfast outside the first three weekends of the month. It was the first time I erected the frame for my largest Trachycarpus in shorts! November was like an indemnification for the rest of the year. Also December started mild with temperatures no lower than -1 deg. C at night. All my pot grown palms remained outside until December 20th.

The following day then gave the starting shot to the coldest winter since the legendary one in 1985. Within one day the temperature dropped from +5 deg. C to -11 deg. C accompanied with heavy snowfall. This was the start of an immense frost period. The temperatures did not rise above freezing until February 4th and in between we registered the following extremes:

December 27th: min:-18°C max:-14°C
December 28th: min:-22°C!! max:-14°C
December 29th: min:-20°C max:-10°C
December 30th: min:-14°C max:-10°C
December 31st: min:-17°C.

Generally snowfall was rare, but the snow remained on the ground for more than 5 weeks. The snow was so cold and dry that it was almost impossible to form a snowball.

On New Year's day a short but heavy snowfall dumped another 10 inches of snow but also ended the extreme cold with temperatures thereafter being mostly between -10 deg. C and 0 deg. C. The westernmost parts of Austria were again spared the worst cold, though normally eastern Austria is much warmer. But also in other parts of Europe this winter brought astounding temperatures: Venice shivered at -9 deg. C and even the lagoons were partly frozen, Rome woke up to -3 deg. C and Naples to -1 deg. C one morning, Valencia at 0 deg. C. Prague froze solid at -23 deg. C and in Poland many people froze to death at -37 deg. C in parts of the country.

Luckily this winter didn’t make everyone nuts, because the duration was rather short with the cold staying around for only 6 weeks. By mid February it was so warm that you could again walk around in shorts at +21 deg. C in the shade. March began even warmer. February and March brought 6 weeks of uninterrupted sunshine and warmth. In late March winter brought the last greetings with a heavy snowfall followed by -7 deg. C at night after which it cleared up.

April was rather cool, but May and June were hot and fabulous as was the whole summer apart from July, which was the wettest month ever on record here. From late July till November 8th we hardly had any rain. On one hand late October brought some very unusual heavy night frosts down to -7 deg. C, which happens probably only once or twice a century here at this time, on the other hand the first half of November was exceptionally warm. We’ve had a couple of days with more than +20 deg. C herearound, some towns in Austria registered even +26 deg. C. Even at night temperatures ranged between +15 deg. C and +20 deg. C. If I had my way it would last the whole winter and I could replace the Trachys with coconut palms. But, to be honest, I’d rather relinquish plans of a coconut plantation than dispense with snow. Yes I know, that’s the sick thing about us palm nuts, in the tropics we’d probably try to grow conifers. Apart from that the whole coconut plan took care of itself with temperatures around zero centigrade now in late November. Good luck for my Trachys.

Trachycarpus fortunei and wagnerianus - the winners. Nightmares of palms turning to mush and of thermometers with barely visible mercury can make a palm enthusiast shudder. This is the time you wish you were a spruce and birch fan. But who’s really interested in this arctic stuff? I’d rather fear for my palms every winter than plant rows of birches, which will still be safe at temperatures unknown in my area since the ice age. The same must hold true for a Texan who sent me an email because he wanted to know if he could successfully overwinter a coconut palm in his garden with heating cables. Different latitude, different palm, same problem.

But was this winter a nightmare at all ? I was exceedingly astounded by the last winter’s results. I lost only 3 of 13 Trachycarpus (twelve fortunei and one 4 foot wagnerianus). Even more interesting this may seem when I tell you that none of my palms, except my largest Trachy, was protected apart from having the leaves tied up. The largest Trachycarpus was again sheltered with a temporary frame and inside this frame the mercury did not fall below -18 deg. C. Therefore it was the only Trachy avoiding complete defoliation, though most leaves were damaged. All the other Trachys were completely burnt down to the trunk, but soon began to grow with a sensational recovery rate.

Trachycarpus wagnerianus was no more than a hairy trunk with a completely brown growing point sticking out. Not a single leaf survived. ‘Now it’s gone’, I thought, though I had some hope it might survive, because the heart was quite solid and did not pull out when I gave it a good tug. Then in March the record race of my Waggy began. It grew so exceedingly fast I could hardly believe it and it underwent a metamorphosis from a stump to a dense leaved palm. Indeed it turned out to be my fastest growing palm with regard to its size and produced no less than 14 new fans!! (The photo shows the Waggy in summer with 10 leaves). Only my largest Trachycarpus fortunei fared better and made 17 new ones, but it is 6 feet taller than my 4 foot Waggy. So forget about all the stories that want to make you believe that Trachycarpus wagnerianus is much slower growing and less hardy than its widespread cousin. Also all the other Trachycarpus grew very well and made a complete recovery after the winter. One astounding thing is that 10 Trachycarpus fortunei (5 pots with two plants each) which I brought up from Udine (Italy), seem to be especially hardy. Six of these have been growing in my garden and four were given away as presents to relatives. These plants had no winter protection and additionally were not planted in favoured positions and despite their rather small size (4 feet) all ten survived without problems. True, they defoliated completely, but they had the best looking centre spear of all the Trachys after the winter, because on all plants it was still green and solid and subsequently these plants made a fast recovery. Unfortunately these plants are too young (4 feet in height) to produce fruit yet, but it’s likely they’ll set fruit in a couple of years. This might bring seeds of very cold hardy Trachycarpus fortunei, but I’ll need a lot of patience until then.

Rhapidophyllum - the loser. Rhapidophyllum hystrix was definitely the loser of the year in my garden. Both plants (5 feet) and the aforementioned seedling succumbed this winter, though they actually looked quite good during the cold snap, but the warmer it became the more their shape deteriorated only to be absolutely dead in spring. I don’t know why these ultra hardy palms did not make it, though they are known to cope with even lower temperatures in climates less “benign” than ours. Anyway my experiments with Rhapidophyllum have come to an end now. It is slow growing, easily tattered by wind and doesn’t have too much charm for a palm. So instead of being plagued with this low clumping palm, in the future I’ll purchase only real palms, like Washingtonia, Brahea or whatever, and thus invest the amount I’ll save in heating cables and enjoy the charm of a large and fast growing palm.

Washingtonias and heating cables. Last winter I tried heating cables for the first time. Formerly I was never really fond of using any kind of heat source to get my palms through the winter, but then I chanced upon a couple of meters of heating cable which was used for frost-protection in a loft. The owners had no use for the cables any more and gave them to me. I had a 4 foot Washingtonia filifera which never really liked the winter inside the greenhouse. It produced lots of new fronds during the summer but lost most of these again during the winter. Also my other Washingtonias in the greenhouse suggest that W. filifera is not really one of the best greenhouse plants in winter. Whether they suffer from too much moisture or darkness or whether they lack regular air circulation or fresh air, I don’t know. Those two prerequisites - gratis heating cables and my filifera’s poor greenhouse performance - were the motivation to plant this palm outside. The trunk of the Washingtonia was wrapped in fleece and the heating cable around it. The leaves were tied up, but were not heated and the whole plant was sheltered by a cold frame. The cables were set to activate at -5 deg. C and deactivate at 0 deg. C.
Actually I didn’t count on the Washingtonia’s survival when the mercury plunged mercilessly, because the protection was in my opinion only sufficient for average winters. The leaves froze solid, because inside the frame it was just as cold as outside, but the plant survived this mad winter, though not in a very good shape, leading to a poor recovery during the summer.

In late February it was joined in the ground by a 10 foot Washingtonia filifera and a 5 foot Washingtonia robusta beneath (see photo). These plants survived a heavy snowfall in late March and -7 deg. C at night without a scratch. They remained in perfect shape even after another two nights with -5 deg. C, though this is said to be a critical temperature for Washingtonia robusta. The clue is that it warmed up considerably during the day which definitely helps palms to survive frosts.

This winter all three Washingtonias will be protected by means of heating cables and I’m sure they have a good chance. I’ll give you a detailed update after the next winter. After my first trials I can only recommend heating cables. First the heating costs are exceedingly low compared with other heat sources. I only needed 50 cents to heat the Washingtonia last winter and also successfully overwintered a Jubaea with costs of only 20 cents! Secondly they are easily established and transport the warmth exactly to the points were it is needed, namely to the palm. And last but not least it enables you to grow more tender species with a minimum of effort. Indeed we are not far from a climate which enables us to grow Butia, Jubaea, Washingtonia, Brahea, Sabal and many, many other relatively frost hardy palms. In most years just a few nights separate us from a tropical looking garden. So why not give mother nature a little leg-up and create the garden you’ve always dreamt of? Certainly buying heating cables is less of a large-scale project than moving to Italy. Heating cables or no, my Trachycarpus will be grown also in the future without heating cables, whether they like it or not.

Evergreens. It was so cold this winter that even Aucubuas were damaged to varying degrees, but they resprouted nicely. However I’ve been surprised that all four Fatsia japonica in my garden came through. Two froze back to the ground the other two were hardly damaged. Also both Magnolia grandiflora fared very well, one of these didn’t have the slightest problems with -22 deg. C. Not a single leaf was damaged after the winter, which was somewhat strange, because last winter it lost most of its leaves at just -19 deg. C. In summer they flowered for the first time.

Cupressus sempervirens ‘pyramidalis’, the Italian cypresses, were reliable as ever and had no problems with this severe winter weather, even though they are planted in a very exposed position and have no shelter. In spring they developed a light bronze tone which they rapidly overcame with new green.

Bella Italia. Of course I was also in Italy a couple of times this year and saw a lot of exciting palms. My first journey led me to Pistoia in mid February. The weather there was cooler than back home in Austria and it was pouring down with rain. The Trachycarpus were all in excellent condition, but the Cycas revolutas looked rather poor. Their leaves were mostly yellow, but the plants themselves seemed to be fine. I was told that sharp frosts down to -12 deg. C this winter caused their poor appearance. Also Udine, which I found out later this year, was not spared by the cold spell: -14 deg. C was simply too much for the 6 metre Phoenix dactylifera of which I reported in my last article. But the absolutely best thing Italy held in store for me this year were two large Jubaea chilensis which I found in a nursery. I almost couldn’t contain myself when I saw those exceptionally beautiful plants and my only problem was how to get those huge plants home. No real palm enthusiast would leave such plants where they are. They were fabulous, the trunks had a circumference of 85 cm and the total height (without the pot) exceeded 5 feet (see photo). To find such palms was beyond my wildest dreams, I had considered it impossible to find such large Jubaeas anywhere for sale in Europe.

Almost as unbelievable was what the nursery owner told me. A friend of his who lives in northern Italy possesses a large Jubaea of seedbearing age with a thick, large trunk. In 1985 this palm allegedly survived -25 deg. C without protection, whereas all Trachycarpus fortunei in the same garden were killed. He said the palm defoliated completely, but resumed growth in spring. Obviously the thick trunk of mature Jubaea can keep off a large extent of frost from the growing point and certainly frosts in northern Italy are not as long-lived as here in Austria, but even so it is astounding and we all know that 1985 brought legendary temperatures to many parts of Italy. Younger plants however, the nursery owner added, pointing at the plants I purchased, would endure ‘only’ -12 deg. to -15 deg. C. Interestingly most of his Jubaea customers were not from the milder parts of northern Italy, but from Austria, Switzerland, South Tyrol and Germany, because they esteem the frost hardiness of those plants, which is not so much of importance in Italy, whereby people rather grasp at the much cheaper Phoenix canariensis, though in my opinion a Phoenix pales beside a Jubaea at any age.

Well, it will be quite a while before my Jubaeas develop their significant thick trunk, thus I’ll carefully protect them during the most severe freezes, hoping that I’ll be able to eat maybe the first coquito when I’m eighty.

Reaching for the fans. Certainly the last two winters cut us palm freaks down to size. Let’s be honest, apart from 1985 the last 30 years hardly brought cold winters, in many years snow was becoming a rarity here in Austria. Though it was quite nice to enjoy spring warmth in winter and to play tennis outside during these warm winters of the late 80’s and early 90’s it was certainly not normal. After a very long absence severe winters seems to have come back again to Europe. Our goal cannot be to create a warmer climate which enables us to grow palms (so there’s no necessity to have the car running in the parking lot and push the greenhouse effect), but should rather aim at raising palms being capable of enduring our climatic conditions. Seen from this point of view the last two winters enabled us to separate the chaff from the wheat, which will bring us closer to growing palms in our countries even in less favoured climatic periods than the last 30 or 40 years. Not that mild winters bring the progress the bad winters do. So, I wish you a severe winter and in doing so, you’ll probably have a mild one!

Update After The Winter 1997/98

We had an incredibly mild winter. Very sunny, exceedingly dry, mostly frost-free and very warm. The highest temperatures in Austria were +26 deg.C in November, approx. +15 deg.C in December and January and +23 deg.C in February (all in the shade). Only in late January we had one lone cold week and on one occasion the temperature dropped even to -14deg.C But the daily highs rose quickly to around freezing and the frosts were dry. In fact it was so warm that by the end of February even cherry and apricot trees were in full flower, many trees have been showing already small green leaflets and the violets and magnolias have been blooming. Spring has been very warm and now in late spring we’re experiencing many hot days, e.g. June 7th brought an official high of +37 deg.C. The Trachycarpus species continued slow but steady growth throughout the winter. They were unheated but most of them were covered with a Styrofoambox to avoid moisture. Result: No damage.

The Jubaea was heated with heating cables below -8 deg. C and also sustained no damage. And finally the Washingtonias were also covered with large Styrofoam boxes and heated with heating cables. I found out that it was really quite easy to keep them frost free even during the coldest days, but I admitted the temperatures to fall as low as -7 deg. C. on several occasions. Result: No leave damage, but spear had to outgrow some fungus on it. In late February I planted out one of my large (5 ft.) Jubaea . I have to concede it is really an exciting sight, compared with Phoenix and Butia palms of equal size.

Trachycarpus wagnerianus has now (June) some 20 fans, after it lost all of them during the 96/97 winter and my largest Trachycarpus fortunei already 30! Eucalyptus parvifolia, E. debeuzevillei and E. niphophila, all about two feet high, sustained no damage as did a Eriobothrya japonica, which overwintered outside the whole winter in a pot. Because the Loquat did so well I planted it permanently in the ground in February. I’m really glad we’re back to warmer winters again after the last two severe ones.