It is probably too early to uncover for your climate.

Wait until you see new growth and SLOWLY uncover a bit at a time until the
last average frost date has passed.

Tim

"mmarteen" wrote in message
om...
I planted a bunch of rugosas and hardy canadian explorers in July and
August of Last year and took special care to tent and mulch them for
the winter in case their roots hadn't established themselves. Now we
are in that zone of Spring-Winter where it can fluctuate between 15
and 50 degrees. Is it better to uncover them a bit so that they don't
get some kind of fungus and risk having them get nipped by a late
frost?

I'm in zone 4a, Minneapolis. Thanks!

mm