Petunia Seedling Update

The petunias that I planted first are almost ready to transplant in to larger pot.    They are 3 weeks old and have their 2nd and 3 leaves starting.   I will wait a few more days as when they are this small - its easy to crush the stem when moving them.  If you crush the stem - the plant will wither away and die.   They are planted in 288 plug trays - I will have a lot of them to transplant.     I plan on selling them on the 26th when we have the neighborhood yard sale - but I am not sure if they are big enough.