If you plant too early, you risk them coming up and a normal frost killing them back to ground. They usually come back, but nothing is gained by the early planting, because they have to regrow.
I am surprised by the St. Pat's day date for your zone 5, I have always heard that was the date for my zone 6.

Hi, I live in northern oklahoma and I planted potatoes this last weekend. I always plant the first week of march if weather permits and have not had a problem, even if there is a frost you already have a root system in place and the foilige comes right back within a few days.
One year my potatoes got frosted 3 times and still made a good crop
Gary

I bought a few seed potatoes and planted them on the soil and covered with straw. I've done this before and it worked. I am only really interested in the new potatoes which you can find easily under the straw. I have some potatoes (not seed potatoes) that are sprouting. Would there be a reason not to go ahead and plant these too since I am going to throw them away and buy more at the grocery store?

Thanks for the answers. I planted some Yukon Gold on the 6th, they're not up yet.I'm planting more as soon as it gets warm this weekend. Then I'll plant some more around the 15th of April. I'll let you know which planting does the best.

Hi, Just posting a update, My first row of potatoes which are Yukon Golds are just coming up now, But no sign of the fingerling potatoes yet.
Good luck with your gardens!
Gary

Its my first time planting potatoes,the soil is clay here in southern utah.What should i do to get the soil ready?
Its april 17th now,is it to late to plant them?I need help thank you

We are in Missouri and Arkansas. You live in a totally different climate. Try the link below. I am not sure the forum is still going; this link is to an old post.

Here is a link that might be useful: Utah forum