I collected seed from my Green Mountain plants, well, from the few that flowered. An interesting phenomenon is the number of these F2s that are chloritic - lacking or low in chlorophyll. I noticed it in the first batch I sowed a month ago, but my recent sowing shows a considerable proportion with charateristic. Of the 16 or so plants I grew from Kelly's original seed 2 plants were chloritic, and succumbed at about the pencil stage.
In this generation, 15 out of 34 emerged seeds are yellow. This will only be a problem if they fail to thrive, so it will be interesting to see what eventuates.