Propagation: Jiffy Mini-Greenhouse for starting seeds, 1 by Sebowe

Sebowe wrote:
Every year I buy flowers for my porch, but decided to start seeds this year instead. I was inspired after buying a pack of Forget-Me-Nots from Dollar Tree a few weeks ago. I'm in an apartment, so my space is somewhat limited, but here's my terrarium with two Jiffy greenhouses! I planted them on Friday, and just noticed the sprouts tonight. For those more experienced, how tall do they need to be before I remove the lids? Thank you!