I’ve just been alerted to these posts by a friend and am only too happy to help another Codonopsis grower if I can. Firstly please refer to
www.codonopsisplants.co.uk where, as Carolyn says, there is lots of helpful information on growing and identifying them.
Specifically, C.gracilis should be treated as a tender biennial and always collect seed if you can to ensure its survival. It is a wonderful plant and worth the effort.
You may be able to maintain C.kawakamii in the garden but here in the UK I also treat that as tender, although perennial.
The Pseudocodons can be a little tricky but there are four that are regularly grown and, once you know them, you’re well on the way. P.vinciflorus has smaller flowers with the distinctive calyx lobes as you have noted. It has the best colour of all of them. P.convolulaceus ssp forrestii is usually the last to flower with large paler flowers and a very dark centre. P.grey-wilsonii has a distinctive purple ring on the blue flower and the pure white form, P.grey-wilsonii Himal Snow, rarely has a purple ring. Certainly I’ve never seen one so your pale form is very interesting.
The seedlings of Cc ovata, cardiophylla and obtusa may flower next year and have almost certainly been grown from seed I sent in last year.
If you’d like to look at the website you can always contact me through that. I look forward to hearing from you further and good luck.
