The Kiwi Connection

New Zealander Keith Boyer gives some topical tips to Tony King on cultivating some of the rarer cold-hardy palms.
Tony King ex. Keith Boyer
Chamaerops No. 3, published online 23-11-2002

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Some readers may have been aware of an impending publication that was set to become the 'bible' for us palm growers in the cooler parts of the world. Keith Boyer, a New Zealander, has spent many years researching the cultivation of cool growing palms and cycads, visiting many in habitat to gain a better understanding of their needs. Sadly, the publisher selected for "Palms and Cycads beyond the Tropics" developed cold feet at the last minute and a new publisher is still being sought.

I have been corresponding with Keith and his latest letter contained practical information on some interesting species that I thought I would share with you.

Despite the distance between our two countries, there are many similarities between palm growing in Europe and New Zealand. Even in Auckland, which is toward the north of the north island, Royal Palms and Fishtail Palms cannot be cultivated out of doors. The summer maximum is 25¾C and on winter days 10¾C, this latter with high rainfall. Frosts, when they occur, are wet' and cause as much damage at -2¾C as would a dry frost of -5¾C in say California.

Strict laws prohibit the importation of palms into New Zealand; so all have to be grown from seed inside the country. It is only during the last 10 years that experimentation with species other than Trachycarpus and Phoenix canariensis has taken place. In many ways this is similar to the situation in the U.K. where growers, especially amateurs, are experimenting with new species outdoors, many of which are grown from seed from the I.P.S. Seed Bank or more likely, from Inge Hoffman's excellent seed service. However, we are somewhat luckier in that we can import more mature specimens from nurseries in warmer parts of the world, to broaden our garden palm flora.

* * *

Here are some of Keith Boyer's observations regarding his attempts at raising some mouth-watering palms from seed. An important recommendation with these is that the outdoor species are planted directly into the ground as seedlings, with heavy mulching of the soil for protection.

Firstly, CEROXYLON, those fantastic wax palms from the high Andes.

"Initially, success was a long time coming", he writes, "with the first three batches rotting at a temperature of 25¾C. Better results were obtained with temperatures below 20¾C. The best method is to fill a pot 3/4 full with a free draining potting mix. The top 1/4 is then filled with either sharp sand or sphagnum moss, with the seeds just pressed below the surface. Germination at 20¾C takes 4-6 months. The resulting seedlings are then grown on in an open mix, containing a good proportion of peat moss to allow good water/oxygen retention."

In Keith's Auckland garden, Ceroxylon grow best during winter under cool, wet conditions. Losses occur occasionally during the summer if the plants are exposed to too much warmth and humidity. 75% shade is advisable for the first few years.

Staying with South American palms, Keith next turned to the two species of PARAJUBAEA: P. cocoides from Ecuador and P. torallyi from Bolivia. Again, constant warmth (at 25¾C) proved disastrous with much of the seed rotting. Simulating the warm days and cool nights of P. cocoides' lofty homeland was much more successful, with, again, an open and free-draining potting mix being used. Germination time was still slow, but once sprouted, a deep pot, (40cm/16") was required to accommodate the roots. After 2 or 3 years, growth becomes very rapid, with the best being made in the spring and autumn months, but also into winter. Summer sees the palms enter a state of dormancy.

If P. cocoides is rare, then its Bolivian cousin, P. torallyi, is even more so. On the 5 seeds received from the Palm Society Seed Bank, Keith used a hacksaw to cut the hard seed coat to a depth of 2mm all the way round. After two weeks, the first germinated and 18 months later, the second! An early fear was that this species would not grow in the Auckland climate. This reasoning was based on the fact that in the wild, P. torallyi inhabits a sandstone landscape at 2700m altitude where very little rain falls during the year, causing it to bear leaves of a more leathery texture than those of P. cocoides. Also the climate here is cooler than in Ecuador. After seeing the young plant perform poorly in the pot, enough courage was summoned to transfer it into the ground and to date is has flourished in loam soil and 2000mm of annual rainfall!

A quick jump now to Asia for the last group of palms to mention: the Fishtails or Caryota palms. Three species are currently proving themselves in Auckland: C. urens, C. obtusa and C. ochlandra - the tallest example of which in New Zealand is 2m. This Chinese Fish Tail palm in Keith's garden grows in a heavy, cold, wet clay where even the Parsley and Polyanthus rot in winter". The only ill effects are caused by the magnesium leaching back into the soil with the cold winter rains, cured by the application of a mineral spray to the foliage in the spring.

I m sure you will agree with me that the information gathered by Keith would be of great value to all of us engaged in cultivating palms in the temperate zone and I sincerely hope that his attempts to find a new publisher will be successful. It would be a great shame if we were to be deprived of the final publication and his years of research go to waste.

Should you wish to contact Keith, or express your support for his work, his address is
Mr. K. Boyer 70 Opanuku Rd., Henderson Valley, Auckland, N. Z.

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