Only advice I can offer this thread is that beans are very fussy about temprature to germinate one degree too low and they wont germinate, three to four degrees or more higher and they will germinate in about a week. I always grow mine in my polytunel, or before I had one, in my hut in compartmented seed trays. The only varieties I have grown are the ones Lidl's sell,one green, one yellow and I've always had a good crop,this year I'm trying a purple Italian variety. When harvesting for the feezer parboil for about a minute and a half with a touch of salt as this keeps their colour, drain and plunge into cold water,bag and freeze. The same can be done for runner beans.