I would take either plants with sentimental value such as the peonies I brought from my grandparents' home after they were both gone, or favorites for which I don't have a current source. In a situation with a smaller yard, I would place a premium on plants that had a long season of interest or several seasons where it brought value to the garden such as spring flowers combined with fall foliage or interesting winter branches or bark.

For me part of my choices would be based on what I could comfortably accommodate. My next home I expect to be less than a mile down the road, so it will be easier to shift things, while my last move involved a longer distance and 3 weeks of camping out with family while problems with the move were ironed out. Happily, the next owner let me divide a few things at a later date.

My first thought was also the peonies. Other than that, I would wait until I get the feel my new space and buy plants accordingly. Bulbs are good.

I'd want to dig up my roses but they are too big and thorny so probably not the best idea . My next choice would be my daylilies ! They travel well. And clematis .. I pay too much to leave them behind .

Sorry you are sad about leaving plants behind !! I still feel heartbroken over my garden being removed shortly after the sale of our Pennsylvania home. I would have taken plants but the new lady said she loved them and enjoyed the garden so much !! Liar. :(

You don't have anything to lose by asking the new owners if you can divide some plants if they don't mind ! Worse they can say is no . If no , then yay for a clean slate and have fun garden dreaming !!!

Lilyfinch, take cuttings of your roses now and root them. It's a lot easier to root roses than move them, and they grow to a good size within just 2 or 3 years.

Clematis also can be rooted relatively easily by pinning down a stem at a node, wounding the stem, and dipping in or dusting with rooting hormone. Cover the stem and don't let the soil get really dry.

I've done this more times than I would like to remember. Learned to take only those that I cannot find to replace, or are very expensive to replace, or extremely slow growing. The potted plants come (considering that some are ceramic pots, 3'hx3'd, that is no small task!). From the ground (new climate depending):

bletilla, some bromeliads, himalayan blue bamboo, the cascading russellia I lost the name for and haven't seen since that purchase, a sprig from the red barleria, some gingers, a Banksia 'Schnapper Point' (even though it has never bloomed, I cannot give up and cannot find a replacement), choysia (growers stopped offering it in my area), red bauhinia, B. albaflora, Ochna serrulata, Phylica pubescens,cuttings from Metrosideros kermadecensis 'Variegata', several of my favorite alstroemerias and a division of some daylilies and a variegated agapanthus, and one of the bergenia that has come with me on every move for the past 30+ years.