Looks like Adiantum caudatum . Hardy only to about z7.

tj

Thanks for that. Everything I see on adiantum caudatum indicates the fronds are singles, with no side-fronds attached. Mine has shorter fronds springing out to the side of the main longer frond. Shouldn't that mean it's something else? But then maybe the plant has variations. Should I go out there right now, dig it up, and put it in a pot inside to avoid the incoming snow? I'm appreciative of any and all advice.

If you like it, and don't want to take the chance, dig it up and bring it inside.

Thanks. I just did bring it in. I still need to know for sure, with no uncertainty, what I've got and what its happy zones are, though. If it's not adiantum caudatum, then it might need to experience freezing temps over the winter to survive.

I'm glad I found this forum. Looking forward to clarity.

OK, I just looked up adiantum online and discovered there are a bunch of different species of adiantum. Mine looks like it's Adiantum hispidulum. Hardy to zone 8. Wow, I'm glad I brought it inside. Thanks, all.

Then again, if it's Adiantum pedatum, I should have left it outside. I can't make up my mind because it's just not clear. Oh my.

Now I think it's Pteris aspericaulis "Tricolor" fern. If yes, then it definitely needs to be inside. These Pteris ferns are labelled as terrarium plants.

garden soil in the house can end up problematic .. watering issues ... plus worms and bugs and stuff ..

you might want to take it back outside on the next nice day.. bare root it.. and repot in a good media .. outside just to make the mess out there ..

indoor humidity in winter might be an issue.. if you have forced air winter heat ... and misting it may not be sufficient to overcome such ...

also ... just for future reference.. snow is just water ... its usually not the issue... it depends how cold it is when it snows ... and how cold the soil is ... and whether it will retain heat this early in the snow season ... regardless ... it got you motivated ...

ken

Thanks, all. I will probably kill it. But I've got a ton of houseplants all of which need humidity. I'm thinking of getting a humidifier for them. Maybe it will survive in my house with all those tropical friends surrounding it. I am definitely motivated.

Misting one single plant doesn't improve humidity at all.

Pretty sure it’s not Asperis aspericaulis. It looks like one of the Adiantums to me.

Have you asked the garden center which Adiantums they sell?

tj

I could ask. That's a thought. Someone would need to dig up the paperwork from early spring to see what they bought. I'm not sure that would be a reasonable request of them. It would take time. I know how these purchases go..... I worked there in the past. No one would know right off the bat.

update July 2021:

I never found out what fern this was, but I brought it inside and kept it watered over last winter. It stayed green, and seemed to be alive but did not put out any growth. But as spring approached, all the fronds dried out and turned brown. In May I planted it outside, just in case there was any life left in it. Now it's the first of July and the plant is a little trooper - it's putting out new growth. The new fronds are small in size, but new ones are appearing and it seems to be happy. I'm going to keep it outside. I'll leave it where it is over the winter and see if it comes back spring of 2022. (I'm north of Boston, zone 6). Hopefully I'll remember to post an update.

Here it is, on July 10. Up close:

From above. Lilies of the Valley, Ginger, Lamium, Creeping Jenny surrounds it. It's so tiny right now.

Here's how this bigger frond is splitting into parts. Does anyone know what this might be? I think it should have stayed outdoors through the winter, maybe. I'm in zone 6.

It looks like Adiantum silvaticum. Also similar looking to Adiantum hispidulum, but this is more of a warmer climate plant than the A. silvaticum.

Photos of A. hispidulum.

One of A. silvaticum.

Thanks, tropicbreezent, I'm looking up adiantum silvaticum online and can't find its hardiness zone anywhere. Do you know? How much cold does it tolerate in the winter?

Its habitat ranges from coastal to mountain ranges, but not usually where snow is likely. Best to shelter it from extreme cold and keep it growing all year round.

I was unable to keep it growing all winter. It went dormant as winter ended and then dried out totally. It looked dead. I planted it outside and now it's coming back. I'm wondering if it is native to New England.

I checked these out again. I've seen many A. hispidulum and A. silvaticum and have many photos. The A. silvaticum occurs naturally in the New England area of Australia. The climate there usually has good rainfall most of the year, but does get drier in the spring. So the plant would be adapted to that pattern, without necessarily dying off totally during the dry.

A. hispidulum is more wide spread also occurring well into the tropics. I have some in pot. Well watered it grows throughout the year. Our dry season is about 5 or six months long and if it doesn't get supplemental water it will die back. But a full 6 months without water would kill it.

In New England USA the dominant naturally occurring Adiantum appears to be A. pedatum. From reliable photos I've seen online it looks more like A. hispidulum, and a little less so like A. silvaticum. You need fully mature fronds to really pick it out.

Thanks, tropicbreeze. I'll keep posting photos as the plant matures. There are photos at the start of this thread that I took back when it was thriving in a pot. They might have mature fronds visible.

Our usual winters here in my part of New England involve snow cover that comes and goes, and temps occasionally down to 10º Farenheit. So, it's wet in the winter, the air is definitely cold. We also have a lot of freeze-thaw-freeze weather.

Here's the best photo I took before the winter. This frond has five "fingers." The smallest two are connected to the two medium ones. It's possible with more maturity this frond might develop into this A. pedatum form. That's what I'm hoping. I want it to survive outside, because I am not bringing it in again this upcoming winter.

The A. pedatum and A. hispidulum are very similar, as in the drawing you've posted. This is a herbarium specimen of A. silvaticum.. Very different in the mature form, but difficult to differentiate when immature.

The reason I'm so interested in what fern this is has to do with whether it will survive the winter. If I conclusively discover what it is and that confirms that there's no possibility it can endure the winter outside here, then maybe I'll bring it in for winter again and try harder to keep it alive. Otherwise, it stays out there.

sw_gardener, thanks for your insights. This fern was out with the shade perennials when I bought it. I got it at the end of the season on sale, and the label was gone. So I originally thought it should stay outside. I also bought a much smaller one in a tiny unlabelled pot that was with the annuals. I figured that one needed to be inside in a terrarium because of the other plants next to it on the shelf. I was motivated by the sale to try these.

But the two ferns looked like they were exactly the same type of fern when I got them home and inspected them closely. So I posted here, and eventually changed my mind about what to do as winter approached, and brought both in. The small one did not make it through the winter inside (no terrarium). No big loss. The replanted larger one is growing steadliy outside now, very happy where I've put it. I have hope for it.

I've read somewhere that winter-hardy maidenhair ferns are hard to keep alive here in New England. We'll see. I never see them growing wild in the woods.