Dig a great big hole around them--maybe about a foot outside the outer diameter of the plants, and at least 2 feet deep. Lift out the plant, soil, roots and all, wrap in damp burlap or put in really big plastic tubs, and transport. Set in equally big holes in your new home and water, being careful to keep them at the same level as they were originally. The flowers might all drop off, but the plants will be okay. Chances are, you will also have to fill in the holes you left at the old property.

If you're going to move them now (better sooner than later in June), let me share some advice I just got from a friend who's a professional gardener. Unfortunately, I had to move my budding peonies to another state this past week. (I can only hope they will actually bloom in their new home, but it's a long shot)

Here's what she said:
"Soak peonies, dig big root ball-packing dirt towards the plant center with shovel as you dig, put into large pot or burlap and re-plant as soon as possible with a little compost in bottom of new hole. If it is sunny (could that be possible?!) cover with a bit of netting for the mid day period. We have moved full grown peonies in June and they bloomed!"

Be careful to follow what ljrmiller said about plant depth.

Peonies are so worth the effort!!
Judye

Just had the same problem, actually! We "rescued" several older peony bushes from yet another teardown house/new construction (grr...don't even get me started!) down the block. Pulled them out about three weeks ago, literally in front of the construction equipment. Was advised by a gardening guru who specializes in peonies to dig a circle around the whole plant and then divide the plant into quarters with a sharp spade. (Soaking would have been great, but was not an option or us since the construction sight had no water or hose hook-up.) His logic is that small divisions root more easily and suffer less transplant shock than larger plants. Replant new divisions at same depth - no more than 2" deep, optimally. I was advised to hope for the best and expect to loose a few shoots. So far, the plants have done fine. No real buds (sigh...) but good clean foliage and healthy stems, so we'll look forward to next year. Also, if you're going to move them, make sure they get plenty of water for the first week or so. Water in the mornings, at the base of the plant, and let it get a good drink. Avoid getting the leaves wet or watering late in the day when the water can remain on the plant overnight. This can casue fungus (blech!) which can be really bad for your plants. Transplanted peonies need to put all their energies into getting settled in their new home, not fighting disease, so take care not to help fungal growth along by leaving wet leaves and stems.

I assume that if you move budding plants, you'll probably loose most/all of the flowers for this year, which is sad but unavoidable. Take heart and know that they'll be great at your new place next season!!!

Good luck. Please let us know how it goes.

I'm just thrilled to report that 2 of the 3 peony bushes I transplanted at the end of May bloomed!!!

I think watering them quite a bit after the transplant helped. We also had a cool spell in New England in June that probably helped too.

The one that didn't bloom (has one flower bud on it) was a brand new plant - had only received it in the fall. It's a Myrtle Tischler and I can't wait until next June to see it open!

Hope the rest of you had success as well!
Judye

Since the blooms will be a handicap in moving why don't you cut them off and enjoy in your house as a cut flower. By removing the blooms you might reduce some of the stress of transplant. Depending on the state of the buds some could continue to open for extended period. Thank you for protecting the plant. Watch the yards of any future houses you rehab to see if you can find other plants. Some of the old gardens had plants rarely seen now.

aept states, "divide the plant into quarters with a sharp spade". This is something that is usually overlooked by most people transplanting peopies out of season (fall).
This is important to dive the peony at this time. I do not really know what it does to the peony other than it has a very high survivial rate if divided when transplanted compared to non divided transplants out of season. It is believed that the divisions sense that it is missing some of its mass and each one sets out to replace the missing mass. It goes into a growing stage on the root system to replace the missing roots out of its desire to survive. Some research studies conclude it is a desire to survive and others conclude the growing stage in the root system is the result of not being overcrowed. All studies that I have seen do conclude that the divided transplant starts producing new root growth and the non divided transplant does not, but stays stagnant reducing the survival rate.