Fall is the best time to split them. My suggestion would be to dig up only part of the plants you want to split vs. uprooting the whole plants and resetting them in the ground. If each plant covers 3' I would think you could leave part of it undisturbed and still get 3-4 eyes on the roots you dig up. If you dig the whole plant and disturb it, then you have a higher probability of foregoing a season of blooms next year.

Wherever you plant them next, prepare the soil thoroughly in advance, and give it some healthy soil. Plant with the eyes no more than 2" below the top of the soil. In fact, since dirt settles and sinks over time, especially if you dig deep to loosen up the soil, I'd plant with the eyes no more than 1" deep, and just cover lightly with soil. You can always add more soil to the top, but if you plant too deep it's tougher to fix that problem.

If someone else is reading this and has more advice or differing advice, please comment.

If I can add to the original poster's question...I am having to transplant/split a peony from Nebraska during Labor Day weekend, so I can plant it in my backyard in Kansas. When I plant the roots in my backyard, should I cut off all the foliage and stems and just plant the bare root, or would you suggest I dig out the foliage/stems with the root and keep it intact when I plant it in my backyard? It's still warm here in Kansas, so I'm thinking the foliage probably won't do much good anyway, but at the same time, I don't want some of the young buds/eyes to start sending up new growth/stems (if I were to cut off all the existing stems). I had this happen last fall when I planted some bare roots I ordered, and I think my peony would have been fuller this spring had it not sent up shoots last fall. I know, sometimes it's just unavoidable, right? Thoughts?

Thank you houdinii. That's kind of what I was thinking, but wanted to double check. These are such beautiful peonies (soft blush pink with hot pink on the tips of the center petals), and I didn't want to miss out on next years blooms.

houdinii's advice is good. Peonies can vary a lot depending on the species, as to the mass of the root. The larger rooted species with a diameter of three feet will be too difficult to dig intact with out breaking a lot of brittle roots. It would be better to use your transplant spade to plunge straight down through the crown of the plant dividing it into two pieces. Now dig up by digging deeply as the root mass will be about two feet deep, each half, or if you want you can leave one half in place.
Houdinii I would cut the stems down to about six inches when you move to Kansas. This will not affect the new buds and the peony should bloom next spring. Al

I second the above advise, I have divided one of mine and
they are blooming great for the last 12+ years, here is a
pic of one , taken this year.It had several more on after
I took this pic.

Caroline, do you know the name of that peony? It is beautiful and it looks like the stems support the flowers very well. Thanks

thyme, I am sorry I do not know the name. It was the first
flower I planted when I moved to town from the country
about 20+ years ago. I have a red one also. I had to move
the red one, I had it in too much shade, didnt bloom
good. I use a ring to help hold the leaves up. They
like to droop with the heavy flowers. I do like it and
wish I could help you on the name.

btw...can somebody please tell me how to put a picture in with my message?
Sure. First you will need to open a Photobucket (Free) account. Secondly, upload your pic there.

then....

1...just type your message,...or in this case a reply to this post, changing the Subject of Posting line by one character.
2...open Photobucket in another tab
3...find the pic you want to post in the message,
4...click on HTML code found in the third box below the pic. It will say copied in yellow,
5...go back and paste the HTML in your message box,
6...hit preview,
You will then see your message, and the actual pic,
and
7... lastly hit submit.

Stop on over to the Test Forum Gallery. We have ongoing pic posting lessons there continuously.

You can add to this thread, or start your own. There are regulars there that can/will readily help you.

Stunning pic Caroline. Thanks for sharing!
Sue

I would like to divide some of the peonies that are at my late Grandma's house but I would have to do it this month has they have sold her house and we have to turn it over the end of May to the new owner. I am sure they are blooming or have bloomed and didn't know if they would survive if I did this. Anyone have any suggestions?

if you really want to move them, follow the same advice as above for dividing a large clump. dividing will make them want to grow more than leaving them whole. give them a good bit of water or do what i do for everything (and it seems to work incredibly well) and leave them in a buck of water for a day or 2 to soak and then replant them. i ahve no idea why this works but all of my roses, raspberries and irises took like champs. i would imagine the peonies would be the same way. i've only ever moved them in the fall so i didn't care what the leaves did.

Thank you so much. 1google search and this exactly was the info I desired. Will report re my outcome

How often should I water my peonies?? Thanks

PeaGreen I see you are a brand new member, welcome to the garden web. It is always better to start a new post than to bring back a three old thread, especially when you have a new subject. Peonies are deep rooted and do not benefit from frequent light watering unless you are in fast draining sandy soil. Your soil will determine how often and how much you water, and of course if your peonies are not established or are newly planted you will need to watch carefully and avoid wilting. Al