Congrats. :-) I start fertilizing when there are good roots showing and use VERY weak dilution. You will not hurt them by using too weak of a solution. I add a tiny amount of a no-burn fertilizer to the water every other day or so. The stuff I use (Schultz liquid) is supposed to be used once a week, at the concentration of 7 drops per gallon of water. For my use, I add a couple of drops per 2 gallons of water... Currently the 1 gallon pots in my sunroom are shooting out new basals like mad on this weak of a dose.

Cheers,
Michelle