Question
I live in the north east US and the ground has already frozen. I want to thin out some Iris plants. Is it too late to do it in early spring as soon as the ground thaws?

Answer
Hi Martin,
Thanx for your question.  Actually, early spring is a great time to thin irises although in my opinion fall is better.  The reason is that many times when the rhizomes are disturbed the plant doesn't bloom for a season.  But if you do this in the fall, the rhizome has all winter to recover and will usually bloom the next spring.

Yes, right after the last hard frost.  As long as the soil doesn't freeze solid, the rhizomes should be fine.  I hope this helps.
Tom