George is 100% correct - forced or florist hydrangeas are very difficult to transition into the landscape in colder zones. They tend to be sold as floral gifts or throw-away plants - enjoy them whilst they are in bloom, then toss them. For one, they are almost always macrophyllas, which are seldom bud hardy in zones lower than 6 without significant winter protection. Nearly all of these bloom on old wood and in colder climates, this wood is killed back by winter cold - no old wood, no flowers, much the same as if you pruned them hard each season (winter is doing the pruning for you!). And they do take time to establish to outdoor growing conditions, even if they prove root hardy. In colder climates, growing paniculatas or arborescens (Annabelle) are better bets as these are very hardy and are reliably good bloomers, plus they bloom on new growth so do not mind the winter dieback. There are some macrophyllas or bigleaf mophead hydrangeas that bloom on both old AND new wood and are considered hardier than the norm.....'Endless Summer' is one but there are others. Unfortunately, these are seldom utilized as forced or florist hydrangeas - you will have to seek them out at garden centers or by mail order. And visiting the Hydrangea forum is an excellent idea. Lots of great info there on overwintering and protecting hydrangeas in colder climates plus suggestions for planting others that will thrive in your climate.

Many tend to be large shrubs so it would be hard to tell if the ones in the picture get no taller than that or if the owner prunes them to keep them that size. There are some dwarf type hydrangeas like Pia, Hornli, etc. that you could check but they may grow too low for the hostas that you plan to get. Measure the heigth that you require, the height of the hostas and then look for hydrangea macrophyllas advertised to grow no higher that you desire. Make sure they will do well in your zone too. By the way, height estimates are estimates so be prepared to prune now and then if the shrubs get too tall or wide. Examples: Pia, Blue Billow, Blue Deckle, Hornli, Masja, Marechal Foch, Shirofuji (white blooms), etc

Thanks so much for advice. hcmcdole: After reading that link, it made sense. I was wondering why I would see some peoples hydrangeas around me and they never pruned them at all, just let them stay ugly during the fall/winter and they were full the next year. hokierustywilliamsbu: Thanks so much for your input! I think I'll just leave them alone. Maybe remove the dead blooms on the ones I do have when they die and thats it.

Plant looks kinda like Jimson Weed. The seeds are the right shape if they are as flat as they look. But I've never seen them darker than brown, usually tan. If the blossoms look like big purple Morning Glory and the seed pods are spiky... pull it out.