Phoenix Canariensis is given in most books as hardy to 20°F (-7°C), that is why I have mine in a big pot that I place in cold shelter when temperatures drop below -5°C (I live in zone 8). However I have been watching 8 of these palms that were planted (in the ground) in a suburban Mall 10 years ago. During this period the record low temperature in the area has been -15°C (5°F) with typical winter lows -7°C to -12°C. The Mall is not in an urban area so the palms do not grow in a potentially warmer microclimate. The palms have thrived throughout the period, without any kind of winter protection, not showing any evidence of frost damage, they are today 10-15 m high. I am now tempted to plant mine in the ground since it is getting big. I got additional encouragement reading the November issue of The Garden (the Journal of the RHS): in page 801 there is the picture of a splendid Phoenix Canariensis planted in the center of a busy roundabout in London. Any encouraging evidence from North America? Gomero
Like the Canary Island pine, these are not a feature here far outside of California (southern Oregon coastal stip has coastal Californian climate). As M. Frankis pointed out on the pine thread, the warm days of places like California (as well as aridity, soil mineral content, probably other factors) prevents occasional low temperatures on par with those of a cooler climate from eliminating them. Various palms are grown by palm enthusiasts in PNW, but only windmill palm has become a common feature. Winters here probably less limiting for many of these than cool summers. Feather palms in particular apt to put out chilled (yellowish) fronds during part of the growing season, indicating it is too cold for them.
Reading into some Palms websites, I have seen that a Phoenix canariensis in Gold Beach, OR is the most northerly known unprotected, large Phoenix palm in the Western Hemisphere. Gomero
i have a 22cm high plant , can i plant this outside in south u.k. , will it get through the winter do u think??