sourcing japanese mountain vegetables (us)

several months ago when alan carter was here and there was a giveaway for his book, he mentioned here about some woody possibilities for the forest garden, namely koshiabura and harigiri, both woody members of araliaceae that grow wild in japan, and whose shoots are foraged in the springtime as sansai - ‘mountain vegetables’.

does anyone have leads on seeds or cuttings for these plants, or others used similarly? the latin names for the two mentioned are Kalopanax septemlobus and Chengiopanax sciadophylloides. i know of some wild domestic araliaceae and have access to several - that’s not what i’m looking for here. alan is in the uk and the sources on his website don’t seem geared towards the us, but i haven’t dug into them too deeply.

It looks like you'll have more luck sourcing Kalopanax septemlobus. i found seeds available at B&T world seeds. Based in France but they ship world wide I believe. There seems to be a few examples in botanic gardens around the US and it is naturalised in some Eastern States - presumably spread by birds: https://www.bostonglobe.com/metro/2015/07/29/invasive-tree-taking-root-may-trace-back-harvard/pI3nBvzsdQ0QRNSb9P7KgN/story.html  I think I got one from Edulis nurseries in the UK last year, but it didn't survive being planted out. I'll have to grow it on a bit next time I try.

I could find very little English language on Chengiopanax sciadophylloides, although there is a little on it's uses here: https://www.specialtyproduce.com/produce/Koshiabura_10469.php
I did find that crug farm plants in the UK list it : https://mailorder.crug-farm.co.uk/default.aspx?pid=9417  but that is the only UK source according to the RHS and I could find no US references.

Nancy Reading wrote: I think I got one from Edulis nurseries in the UK last year, but it didn't survive being planted out. I'll have to grow it on a bit next time I try.

Ha! I went to check and it seems OK! Only about 6in tall so far and we've still got the worst of the winter to go, but looking good!