Posted: 30/07/2014 at 08:55
Heleniums do not like dry soil. They enjoy wet soils. However, I would incorporate some grit in the mixture locally.
Aconitums.....different vsrieties. I have one in flower now and another that flowers later.
Acteas.....your soil should be ideal.
Anything you plant should be helped by adding grit as said before......plenty for frikartii Monch which is worth trying. It will flower forever .
Hackonechloa will certainly love your heavy wet soil....ok, a grass amd deciduous but womderful from spring to autumn
Agree with Beaus Mum about astrantias too. Some very nice varieties....I grow a tall white, jewel like, one called jumble hole but dark red, pink, white and even a beautiful foliage variety Sunningdale Variegated.
If you're growing penstemons there all the above should do be fine too