When to plant perennials in zone 5?

I've got the planting itch. Living in a colder climate,I'm wondering when it's safe to plant plants such as lily's of the valley and clematis,and day-lilies.

When to plant perennials in zone 5?
I live in zone 5 and always considered tax day in April to be the last major frost day.

Making it tax day also helps me to remember exactly when I can start planting t. That %26amp; I usually use the refund for garden stuff.

My Clematis is already flowering. You Day lilies could have been planted last fall so they'd be flowering about now. But you can still plant them now just don't expect flowers from them this year. Probably just get the green leafy part this year.
Reply:I'm in Zone 5, and I plant them anytime I get them. Because they are perennial, it doesn't matter
Reply:You can plant perennials anytime the ground is not frozen. You can usually tell when the garden centers start having perennials in your area. Lily of the valley will multiply so make sure you don't plant them close to where you don't want them to grow. I started with 2 plants around a tree and they have multiplied many times that now they have taken over one big area of a flower bed. The more I try to pull them up or dig them the next year I have twice as many. They grow under the landscape mat I put down to control weeks.
Reply:In zone 5 perennials can be planted anytime after about April 15. Of course this year, we still had snow on the ground, so I waited a couple of weeks for thr ground temp to warm up. You can still plant safely thru the end of June - after that it may be too hot %26amp; dry for plants to get a good start. Then we can start planting again around Labor Day.
Reply:I live in zone 5 in western New York . You could plant now or wait till the middle or end of May. We've had snow on Mothers Day around here.