Short answer, it depends...

It depends primarily on the type of fern and the growing location.

If the ferns are in a location with a lot of sun, consider making a
temporary shade for them.

Also, did you disturb the roots much during transplant?
At this point in the season, I find it best to slide the whole root-ball
out of the container, plop it into the pre-dug hole, and then fill the
space around the root-ball with soil. I always stage some dry grass clippings
or loose mulch around the fern's crown to provide additional shade
during the transition period.

Josh

Thanks so much for the info, Josh. Well, I didn't do the digging myself and I'm not sure what kind of fern it is (neither is my friend - they were planted by someone else) but it gets very tall (3 feet or so). I was presented with the ferns and they each had approx 4" diameter of rootball attached with about 5-6 fronds each. Once the trees are fully leafed out, they will be getting at most 1/2 sun if not less so they are in a fairly shaded spot. I did mulch them well with leaf mold so I hope they will at least survive until next year when their new foliage will be able to stay upright! My main concern is whether or not I should cut down the existing flopping foliage - my gut feeling is not to since I don't know how the plant will do photo synthesis then, but any input will be appreciated.

Don't cut the floppy foliage yet. Let the ferns take back what water or nutrients they can. I wouldn't trim the old fronds until next spring, when you have confirmation of new fronds.

Can you take a picture, by chance?

Josh

Josh is right. Don't cut the foliage because if you do, the plant will not be able to gather food, and will have to spend all it's energy putting out new leaves, instead of root repair and new roots.

So what if they are floppy? If you provide all the nutrients and water the ferns need, the fronds may soon become upright after the plant does root repair and re-establishment.

Thanks both! It's not that I have a problem with flopping foliage (although I confess that I prefer it to be upright in the case of ferns), but the reason for wanting to cut it down is that when transplanting ordinary perennials, it is always a good idea to cut off some of the foliage so the plant can concentrate on it's root system rather than on providing nutrients to the foliage. But if ferns are different that way, I happily accept to leave them be ;-)

Marianne

PS: I don't have time to download a picture right now, but I'll try in a few weeks since I'm a novice at the picture posting thing and I know it will take me a while to get it right :-)

With my woodwardia, which is an evergreen, I bend the ugly, yellowed fronds about halfway along the frond, and I pluck the fronds of spotted, snow/frost-burned dead material. This trauma seems to hasten the retrieval of water/nutrients, and very soon the old fronds are completely browned. At this point, I cut them where I made the initial bend. Then, I wait for the frond to dry further. Finally, I trim the spent frond to about an inch and a half from the crown. I leave the stub alone until the following year, at which point I cut it within a half inch of the crown.

Josh