Hello. It depends what kind of fertilizer you have ie Organic or inorganic (such as miracle grow). Either way, fertilizer usually comes with some directions. I've had luck fertilizing my transplants after about a week or two of putting them in.

-mac

I have miracle grow, and I don't have the instructions anymore. I just wasn't sure if the full strength fertilizer would hurt the transplants or not. Guess I'll wait a littlw while and then feed them with some diluted fertilizer.

Full strength MG won't hurt them. Lettuce likes a good amount of nitrogen to grow quickly. That's the first of the 3 numbers on the label.

Okay, thank you. This is my first time to grow lettuce, so I'm learning.

YB,
I also grow lettuce, a lot of it. I use Neptune's Harvest fish and seaweek with great success. MG works with out a doubt, my I like the organic and there is no possiblilty of burning with it.

1eyedJack and the Dawg