These are very moisture loving species and prefer areas that stay evenly moist all through the growing season, like alongside or even in a pond or slow moving stream. It is hard to duplicate these conditions in regular soil if there is much of a presence from larger, woody plants like mature trees or big shrubs - their larger, more aggressive root systems will rob smaller plants of needed moisture. If planted in regular garden soils rather than a wetland area, make sure there is little root competition from larger plants and water enough to keep the soil consistantly damp.

I have planted a few dozen and am amazed how they will not remain in one spot but literally a few inches over they do fine. I would say yours are gone for good. I also have had litte or no luck transplanting after they divide. I am in a damp shade too. good luck

Don't give up!! At my old house, they grew in the very worst conditions, and each fall I was SURE they had died. Each spring, they came back, bloomed their lil' heads off, and each fall looked dead again.

Pat

P. denticulata isn't that fussed about shade. In one garden I know they left the cosy conditions of the garden bed and seeded themselves in the gravel of the driveway - and flourished.

They got sun for most of the day, but their feet were protected by the gravel and they could easily reach fairly reliable water - even under hard summer conditions.

They grew in company with Monarda which was burgeoning in water coming down the drainpipe and into a soakpit.

P. vialli I find to be a temperamental creature - but it again needs reasonable amounts of sun and a loose soil which holds moisture/has plenty of humus but doesn't get too boggy.

If I was planting round a pond I'd probably plant on mounds so the crown was clear of any flooding.

They seem to do well in company with the 'swamp' rhododendrons, Astrantia, Iris kaempferi, Clematis buchanii.

I'd be looking more for good air movement for cooling, rather than shade, I think.

I've also found them to survive droughting. Not 'happy' as such, but they did recover to bloom the following season.