Once sprouted, the seed has begun growing. It has basically become a vegetable at that point, and will last no longer than purchased bean sprouts (which is not long). I've had shellies sprout in the fridge, so refrigeration will slow, but not stop, their growth. My suggestion would be to promptly plant the sprouted seeds, give them away for someone else to plant, or just throw them in the compost pile.

As for spacing... I thin Fortex to 2 @ 12", and they densely cover a 6.5' trellis. Kentucky Wonder is more vigorous, I space them 12" apart to get the same full coverage. I've not grown Blauhilde, but if it is similar to Trionfo Violetto - which is fairly wispy - it could use the same spacing as Fortex.

Its been over 20 years since I last grew Rattlesnake, I don't remember enough about it to make a recommendation.

Thank you, Zeedman!