I've grown an impressive stand of Oregon Sugar Pod II snow peas this year, but unfortunately they have proven to be a bit tough. The weather here has been very cool this summer (only a few days over 70 degrees- miserable!), but otherwise the plants themselves have seemed to be rather happy. I have been picking them before they reach their purported 4 1/2" in size, much earlier in fact, but they still seem to be rather tough. I believe my seeds were a burpee seed rack purchase.

Does anyone know what environmental factors might cause these to be so tough?