In some ways this list reads a little like the ‘Palm trees that always look good’ but we’ve tried to mix things up a little and throw in some other species too. Here we’ve looked specifically at palms that will tolerate more than a little frost.
Coming from southern Brazil and Argentina the Jelly Palm is used to icy blasts well below zero from the Andes. In the UK this palm is regarded as hardy in all but the coldest of locations. During the record-breaking winters of 2009/10 and 2010/11 we lost a number of palm trees in our London garden but despite -14°C and days below zero our Jelly Palms were barely touched. (Note that most books will tell you they are hardy to around -8°C to -10°C so we advise that you err on the side of caution). Regardless, you’ll be hard-pressed to find a location in New Zealand where this palm won’t thrive.
We’ve put this one in as a bit of a teaser. The Himalayan Fishtail Palm isn’t hardy in the sense it’ll sail through -8°C with ease but for such a tropical looking palm it’s tougher than it first appears. Reliable data on cold-hardiness is difficult to come by for this species (likely due to where the seed was collected and the nature of the cold) but estimates range from -3°C to -7°C. That puts it within reach of much of coastal New Zealand. Not bad for a palm that’s perhaps better associated with steamy jungles of Southeast Asia.
Much like Caryota maxima we’ve included the (yes, we’ll repeat, non-spreading) Bamboo Palm for its relative hardiness given its tropical appearance. Like many species of Chamaedorea it’s well-suited to New Zealand’s mild climate requiring only a little warmth to grow. It is however one of the hardiest Chamaedorea species with an ability to tolerate temperatures down to around -6°C to -8°C. That means practically anywhere in the country. Can’t you just imagine these along a border or in pots outside a front door? Why not be the first to plant one in your town?
If we’re going to discuss hardy species of Chamaedorea then one can’t go past the Radicalis Palm, Chamaedorea radicalis. This is a highly variable palm (some forms remaining trunk-less while others growing to become solitary palms) which can take a reported -12°C. That’ll see off practically everything else in the garden but the hardy Radicalis Palm will still be there!
If you’re looking for a frost hardy palm that will take just about anything the weather can throw at it and just keep growing forever then the Mediterranean Fan Palm is the best bet. It’s slow but sure and can take temperatures of between -6°C and -10°C. Ours came through -14°C with quite a bit of leaf damage but quickly shrugged this off with a new flush of spring growth. The rarer blue form, the Blue Mediterranean Fan Palm (Chamaerops humilis var. cerifera), is probably just as hardy. We’ve seen these growing through the snow and ice in mid-winter along the windswept Tizi n'Tichka pass in the Atlas Mountains.
Rather than picking Livistona australis we’ve opted for Livistona decipiens, the Ribbon Fan Palm, as a good example of a frost hardy Livistona. Despite its tropical origins (North Queensland) this palm tree is known to take temperatures down to around -6°C. Whilst it’s not grown quickly a completely unprotected plant in our London garden has seen off icy temperatures for several years now.
There are several contenders for hardiest Phoenix palm but we’ve picked the Date Palm for a change. There are certainly examples of the common Phoenix canariensis growing in southern Canterbury. In fact as a child I remember being amazed by these beautiful palms in Christchurch. The Date Palm however can take not only cold weather (probably to -6°C) but wins our vote on account of being much more exotic looking.
For such a delicate looking palm the Lady Palm is practically impervious to frost. It’s a palm that does better in shaded positions but will take a fair degree of ice and snow. Hardy to around -6°C even when cut down by sustained temperatures below zero it can still regenerate from the ground. In much the same way that we’d recommend Chamaedorea microspadix as the palm for all parts of the country this applies equally to Rhapis excelsa.
Sabal palms grow throughout the Caribbean as well as the Gulf of Mexico and southeast United States. As a consequence several species receive considerable cold in their native environment. Sabal minor, the Dwarf Palmetto Palm, which is a pleasing blue/grey colour grows to around 4-5m (eventually, it’s very slow) and can withstand to temperatures to around -15°C. It does need some heat to grow but even in Northland’s mild climate it puts on good summer growth.
As we’ve noted previously, the Chinese Windmill Palm, whilst a scruffy plant in warm locations, can with the right climate (and parentage), be a large a beautiful palm in cooler locations. It’s also tough. During bitter freezes in London in the 2009/10 and 2010/11 winters many other species of palms were wiped out. Our Trachycarpus palms weren’t even protected; we never bothered to knock the snow and ice off them and in spring they just carried on as if nothing had happened. Even small palms of other Trachycarpus species that turned black by the end of winter quickly recovered in spring. The Windmill Palm is reported to take temperatures down to -15°C and requires little warmth to begin growing in spring (ours in London would start sending out flushes of new leaves during the cold and windy month of March).