Hardy Tropicals UK

I'm wondering if Cyatheas and Dicksonias keep pumping out fronds all year in New Zealand or do they naturally go dormant and stop growing for 4-6 months like our native ferns do?

I read that Dicksonia antarctica have to be kept at +2*c in transit to keep them dormant.

The simple answer is I don't know for sure, but many plants stop growing below a certain temperature even if they don't have a dormant season as such.

With Dicksonia antarctica as there is a rhizome at the centre of the trunk they have enough energy stored to kick out a flush when good growing conditions return, even if defoliated. This 'flushing in spring suggests they may go dormant over winter. Cyathera are different as they don't 'flush,' instead producing a succession of fronds. This may suggest that they just continue all year round while conditions are good enough.

When we visited the south Island in New Zealand the temperate rainforests were epic and FULL of tree ferns. They looked as if they produced fronds all year round to me.

I have to find a US supplier or a supplier who ships to the US and try one of these next year

Hi all, I remember driving down the great ocean rd victoria, Australia to visit family in Portland.The tree ferns in the cape otway national park are out of the world. Ok the gum trees maybe 40ft plus but in the forest it is full of tree ferns im talking about tree ferns 15ft high which might not seem high but the trunks where aleast 2ft across. Amazing..... Family over there said the fonds never stop producing. Maybe because they never see frost????

That all depends on the species AND it's growing range; tropical species never go to sleep, species from colder areas sometimes go to sleep, but only if they grow in colder areas. Cyathea australis e.g. does grow in cold habitats where it can shed it's fronds every winter. BUT it also grows in warmer areas where is keps all the fronds all year round.

Kind regards,
Remko.

griphuz wrote: Cyathea australis e.g. does grow in cold habitats where it can shed its fronds every winter. ....

A deciduous tree fern?? Does that apply to scattered individuals, or whole populations, in colder areas? Are these plants obligate deciduous (drop fronds every winter, even milder ones, at their location), or only deciduous in bad winters? Wonder if it would be a better success in Britain than typical evergreen specimens?

Conifers wrote:

griphuz wrote: Cyathea australis e.g. does grow in cold habitats where it can shed its fronds every winter. ....

A deciduous tree fern?? Does that apply to scattered individuals, or whole populations, in colder areas? Are these plants obligate deciduous (drop fronds every winter, even milder ones, at their location), or only deciduous in bad winters? Wonder if it would be a better success in Britain than typical evergreen specimens?

My Yorkshire grown C australis remained evergreen last winter.

Let me put it this way: Some treeferns (like C. australis) can take it (naturally) to loose their fronds every year, or every other year, but will only loose their fronds if the weather forces them to. If conditions are milder/ less severe they will offcourse keep the fronds whenever possible.

I wouldn't want to call it deciduous however, because deciduous trees also drop their leaves if conditions even if the weather stays ok,..right?

Kind regards,
Remko.

Down here in Tasmania even in the mildest areas like Bruny Island Dicksonia antarctica don't produce any fronds at all from May - late September ! I know this for sure as on my father in laws land he has about 70 huge tree ferns some with 12 ft of clear trunk that usually only flush 2 -3 times a year !