All three, actually!
Well, the peas have come down to make room for some squash and climbing beans, and the vote (mine!) is in. Here's the tally:
Amish Snap Pea: Winner for earliest and for taste.
Johnny's Snap Pea: Winner for yield.
Cascadia: Winner for disease-resistance.
I really think all three were winners and I'd definitely plant the same combination next year. (Although I have to admit this is partly because I'm cheap and I have lots of seed peas left over!) But overall I was really pleased with how these varieties worked out. The fact that the Amish snap peas produced first staggered the pea harvest without having to stagger the planting: I put all the peas in the ground at the same time. As the Amish peas were finishing the Johnny's snap peas were taking off, with the Cascadia not far behind. As far as yield goes, the Johnny's really won out. Of course I didn't count the number of pea plants I wound up with of each kind so this isn't really a very "scientific" study, but the Johnny's were so far ahead of the other two I think it's pretty obvious:
Amish: 1 lb
Cascadia: 1 3/4 lb
Johnny's: 3 lbs !! (That's a lot of peas!)
Amish (left), Johnny's (middle), Cascadia (right)
Now, in terms of taste, I think the Amish won hands down. They were very delicate, but sweet even if under or over-ripe. Both the Johnny's and Cascadia peas were larger than the Amish, and although they were both delicious, (sweet, crisp, and juicy) I really loved the Amish snap peas the best.
Although I really didn't have any problems with disease of any kind (that I could see), a few of the Amish and Johnny's snap pea pods had either a few spots or were a bit deformed. I really didn't notice this at all with the Cascadia, which were bred for disease resistance in the Pacific Northwest.
It's been a terrific pea season and I'm a bit sorry to see it go. But with the baby carrots, parsnips and beets starting to make an appearance I'm sure I'll get over it!