when to separate/thin seedlings?
OK, so I had the 20c seeds and the lettuce germination rate was terrible, so I wasn't sure how the cucumber germination rate was so I planted 2 per cell. well, it figures they all came up LOL! so.... when should I separate them? what is the optimal time? when they're small, 1st set of leaves, second? when I put them outside? or... a friend said she'd just leave them that way. what is the best option?