Interesting. One generally doesn't think of non-tropical ferns as a group needing very high temps. to thrive but I suppose I can believe it for that one. From a very cursory web search it seems W. unigemmata is from some elevation in southern China, high enough to where summers might be a bit cool, whilst W. orientalis is found at low elevations in southerly Japan, where summers would be very hot. At least you can grow the similar looking (to use non-fern specialists) W. fimbriata with ease.

FWIW I tried both W. unigemmata and a couple inexpensive W. fimbriata from Forestfarm last spring. All were very small plants, but the W. fimbriata developed much faster and held up better in summer 2013, which was relatively "cool" and wet by our standards, but still had much hotter, muggier weather than what W. fimbriata is used to. Whereas of course you would have expected the Asian species to do better here, especially in a summer where each month had 6-10 inches of rain. Alas, they both died this winter, which was the coldest in 20 years. Far Reaches was selling W. unigemmata as zn 7 which seems totally incorrect...I could list several zn 8 plants that still managed to survive this winter because I had good snowcover. So if I want to fiddle (no pun intended...) with a giant chain fern again, I'd probably try another W. fimbriata, since it doesn't seem to mind my hot weather at all, and hope for enough mild winters to get one established. A W. fimbriata came closer to surviving the winter: the one in a more sheltered spot still had some green fronds, but the core was dead. (heart? whatever they call it in fernology) OTOH the W. unigemmata seemed to completely blacken out after the first dip to 3F, even under snow cover.

I did plant W. fimbriata and it did great in fact, it did so great, I gave it away because it was really huge and did not stop growing and I did not really want to host it in the space I had.
W. unigemmata I would like to try that if I could find it even for sale.
I would grow W. fimbriata again, but it was just not as pretty as orientalis. It is kind of huge and bushy all over and orientalis is graceful.
Orientalis is doing ok, now as a house plant, the cat likes to sit over it, and it seems to be making new fronds now.

Apparently that one can "go crazy" in coastal Northern California, if you have a heat wave!
http://forums.gardenweb.com/forums/load/crypto/msg0822395322590.html

The thing to remember, as I've posted elsewhere on GW, is current hot summer climates had cooler summers during ice ages. The converse is generally not true: coastal California has never had summers like the the eastern US. So you expect most plants from the east coast of US or low-elevation east Asia to do well with the low dewpoints and cool nights of maritimes climates, and in fact they do. Likewise most non-geophytic plants from California and certain like climates (but not all of them) struggling in a hot humid climate. Rosemary, though, grows fine even in the deep south. Why? The Mediterreanean is right now more humid in summer in California (Rome getting roughly 1" of rainfall in June, July and August, for example) and at times in the past was probably even more so. The place that's closer to coastal California in long-term historical climate is the Azores...and indeed a couple Azorean plants I tried even as annuals and winter-protected temperrenials died pretty quickly when dewpoints skyrocketed in summer. (A couple Echiums, for example...though lesser Echiums from continental Europe are fine here. Aeoniums aren't happy but they will persist as young plants; when they get big a rain storm usually causes them to rot)

Here is a link that might be useful: http://forums.gardenweb.com/forums/load/crypto/msg0822395322590.html

I see W. unigemmata and it might work for me outside, but when I looked at this link I noticed it said W. fimbriata will grow 9 feet tall. I gave it away when it was much bigger then that photo even. It would be good if I had a mostly empty garden, I was looking to fill up. But, Orientalis needs a green house even in san Francisco which is zone 10, it may do ok in Hawaii or San Deigo Zone 11, but it would need a lot water in San Deigo. I am really into tropical plants, I just wish I could grow them better here.

Here is a link that might be useful: W. unigemmata for sale here

My Orientalis made baby ferns also if I would leave the old fronds on but I cut them off. I wanted the plant to conserve energy, but not making those babies. I was not sure they would be viable, anyway. Half Moon Bay Nursery has Orientalis for sale, but they have a green house situation. And a heated green house, when I buy plants there, the die at once as they are not with the program of being outside in this climate. Half Moon Bay has very similar conditions to San Francisco. But, its was good to find out they carry Orientalis. I assume it's really big in Hawaii and San Diego.

Just to clarify a bit more, because a certain aspect of my post is actually confusing, here's a rank of the world's Mediterranean climates in terms of their paucity of high summer dewpoints:
Chile
California
western AU
the Cape
the Mediterranean itself

And this is congruent with my experience in trying to grow plants from such regions in my area with high dewpoints...with the caveat I noted before that some types of plants (geophytes, bromeliads, and probably many ferns) are exceptions to the rule. Again, discounting the fact my winters are too cold for many plants from these climates: I'm only talking about summer survival and for something like an Aeonium, it's obviously in a pot and I'm parking it in what is essentially a cool greenhouse, during winter.

OK, I see, I think.
But W. orientalis would need a greenhouse in San Fran. to boost summer temps and dewpoints. It grows in zn 9 parts of southern Japan so winters are not the problem. All of the immediate marine influenced Bay Area is zn 10, and in fact western (mostly*) gardeners in southern Japan struggle with many plants you take for granted.
* I say this not to seem racially insensitive but to point out the Japanese gardening style is not as reliant on exotics as that of say, the British Isles

This post was edited by davidrt28 on Tue, Nov 18, 14 at 15:13

What plants could I grow in San Francisco that would not make it Southern Japan? I am just curious. So, it gets too hot there in the summer?

Well, right...anything requiring cool summers isn't going to be possible in southern Japan. But I was talking more of zn 10 subtropicals. For example Cyathea australis apparently grow in the most sheltered urban gardens of Fukuoka but not over most of Kyushu, becuase colder winters still drop into the 20s.

They don't sell them anymore. I assume it was too hard to keep them and they keep dying and people want their money back, so they don't sell them any more. I would like to know how they do in San Diego.

Here is a link that might be useful: there are two type here on this site of plant delights

Hhhmmmm, well I'm sure I saw some quite a few Cyathea in the Bay area. More in botanic and public gardens of course: being able to grow doesn't mean easy to grow. And I perhaps shouldn't base my example on a report from one or two gardeners in Japan. In any case, it's a comparison between a fairly mild climate (southern Japan), and a very mild climate (Bay Area). I also saw Norfolk Island pines and a couple other strange Araucaria in San Francisco and my guess is most of Kyushu is a bit too cold for them. All time record lows are -3C/27F for San Fran proper, -4C/24F for Berkeley; I'd guess the figures are slightly lower for most of southern Japan. (But by no means much lower: a lot of American gardeners forget that Japan is both protected by the Siberian High and an Island so has much milder winters: the record lows for Tokyo and various other large Japanese cities are only around 20F versus single digits or below on the US east coast all the way down to Florida & Texas)

This fern goes dormant in the winter but comes back the problem this year it did not warm up at night and therefore it refused to produce new fronds.