Cyathea tomentosissima is a rather small tree fern that hails from the cool mountain cloudforests and grasslands of New Guniea at very high elevations.  This is a climate lacking in seasonal extremes, except for the intensity of the sunlight, nothing like any of the climates in the temparate Northern Hemisphere.  This treefern seems to have found its way into cultivation in Europe, Australia, and even the United States, though it is still overall very rare.

It does not grow as fast as most of the other tree ferns, and its ultimate size is only about 8' tall with fronds up to 4' long under good conditions.  Its small size makes it easy to incorporate into a city garden, and it will also grow well in pots or tubs.  Also, it is not much of a chore to wrap up such a little fern to protect it from the winter cold.

Despite its origin in a perpetually cool climate, it seems to be strangely and remarkably adaptable, in fact one of the most cool- and heat-tolerant tree ferns around.  The combination of heat and dryness, however, will be the death of it; but unlike many highland plants it can withstand any amount of heat so long as it has enough moisture.  It will do well if kept wet in the summer and also tolerates dry conditions well as long as it is cool.  It is also said to do well indoors under cool conditions.  Mine has also done well with our very wet winters here in western Washington, and it has tolerated temperatures down to 26°F as a young plant.  It may be significantly hardier than this (one source, in fact, reports it has withstood 16°F in Britain), and as far as I am aware the limits of its hardiness have not yet been found.  Unfortunately I lost mine in the exceptionally hot, dry summer of 1998.