Chusan Palm (Trachycarpus fortunei)

(Photo taken at Mount Stewart, Co.Down, N.Ireland)

This appears to be one of the best palms for the British climate. Hardy to -15°C (5°F) and also (simultaneously) tolerant of wet. In fact it prefers a cool, damp climate and is supposed to be difficult to grow in the tropics (you didn't expect that of a palm did you?). Worst thing about it is that strong winds can damage its leaves (fan shaped leaves which can grow to 4 feet in diameter). Examples of t.fortunei can be seen at various locations in N.Ireland.

Other species/variants:

Miniature Chusan Palm (T.wagnerianus) - smaller, stiffer leaves so more tolerant of wind.

T.martianus, T.takil, T.Latisectus, T.nanus, T.oreophilis, T.princeps (one or two of these are less hardy than t.fortunei).

Mediterranean Fan Palm (Chamaerops humilis)

(Photo taken at Mount Stewart, Co.Down, N.Ireland)

Hardy to -10°C (14°F), tolerant of wet soil (although must have good drainage), strong winds, etc.

Other variants:

C.humilis "vulcano", C.humilis "cerifera" (blue version).

Jelly Palm (Butia capitata)

-10 to -12°C (10 to 14°F). This is one of the best feather palms for the British Isles. Slow growing up to 25ft or so, likes some summer heat but does not demand it. Also B.eriospatha, B.odorata, B.yatay.

Chilean Wine Palm (Jubaea chilensis)

Another feather palm , supposed to tolerate temperatures as low as -14°C (8°F) once established. Unfortunately very slow growing. May eventually reach 70ft with a trunk 6ft in diameter, but a small plant won't grow this much in your lifetime.

Hardy Parlour Palm (Chamaedorea radicalis)

Small feather palm related to the parlour palm (C.elegans) which most people seem to have as a house plant. More hardy though : -6 to -8°C (17 to 21°F).

Another similarly hardy palm is C.microspadix.

Needle Palm (Rhapidophyllum hystrix)

Has nasty sharp needles (hence the name) at its base.

Dwarf Palmetto (Sabal minor)

Hardiest sabal and supposed to be virtually as hardy as the needle palm. Everything I said about the needle palm applies to the dwarf palmetto also (apart from the bit about the needles).

There are many other cold-hardy sabal species worth a try (although I suspect that all sabals will have the problem of the lack of summer heat in our climate to some degree).

Very hardy (-10 to -15°C?) and now more widely available, if a bit expensive!

Also T.acanthacoma (possibly less hardy).

Amazing blue-leaved palm from Mexico. Supposed to be hardy to -10°C but needs very well drained soil.

Also B.edulis (less hardy I think).

Thought to be one of the hardiest of all palms (perhaps to -18°C). However its desert origin (Pakistan, Afghanistan) means that it requires very dry soil. It is also monocarpic, i.e. dies after flowering. However new growth replaces the old.

+ many more! And that's the great thing about this type of gardening - growers are just beginning to discover the true hardiness of these plants. As they become more widely available at a reasonable cost, this list could well expand!

Yucca filamentosa

Small spiky shrub, fully hardy in the UK.

Yucca gloriosa variegata

Small variegated spiky shrub, really stands out. -10°C (14°F).

Note on yuccas: the above plants are monocarpic, i.e. once they flower, that growing point dies. However new growth replaces it.

Also: Y. Rostrata + several others.....

Japanese banana (Musa basjoo)

(Photo taken at Mount Stewart, Co.Down, N.Ireland)

Fast-growing banana with huge leaves (6ft). More exotic-looking than some palms! Very root-hardy but leaves and trunk need protection during heavy frosts. If the plant is cold-damaged it usually grows from the base up the following year. Up to 15ft in height.

Also: M.sikkimensis.

Dicksonia antarctica

(Photo taken at Mount Stewart, Co.Down, N.Ireland)

Fern with a trunk. Grows large leaves very quickly in summer but trunk only grows about an inch a year. OK down to -5°C (23°F). This temperature refers to the leaves - the plant is supposed to be root hardy to much lower temperatures.

Other tree ferns: Dicksonia fibrosa, D.squarrosa, Cyathea australis, C.medullaris (some of these are less hardy).

Haven't tried these. Supposed to be fully hardy and fast-growing. I have however tried the supposedly less robust pleioblastus species, with great success. Beware their invasiveness, though.....

(Photo taken at Mount Stewart, Co.Down, N.Ireland)

From Australia / New Zealand. Spiky tree growing to 15-20 ft. In abundance in Northern Ireland - some really huge ones, especially near the coasts. Strangely, although this is the "palm" everyone grows (at least in N.Ireland), it's hardiness may be as low as -7°C (19°F) - in other words much less hardy than some of the true palms! Also - C.indivisa (large-leaved version - less hardy?).

Cycas panzihuaensis

Hardiest cycad. Cycads are a bit palm-like but are noticeably different. This is the only one recommended for the garden but some more adventurous British gardeners have tried C.revoluta and have concluded that it too is more hardy than first thought!

Agave americana (variegata)

Varigated (or not) spiky succulent. Can grow to a few feet. Discovered to be more hardy than previously thought, but it needs extremely well-drained soil.. Like the yuccas, it is monocarpic. In addition, "pups" grow around the main stem - these can be separated from the plant.

Also: A.parryi, A.palmeri, A.utahensis, etc.