do plants grown in windowsill need to be hardened off ?

Question

I have peppers growing on my south facing windowsill and I was wondering if they need to be hardened off the same way as plants grown under a grow light?

Answer 1

Yes, even more so than those grown under light. They will not be used to the high intensity sunlight, since your windows will filter out most UV or drying winds. Start them out with about 4 hours of outside time per day for about a week. This will be plenty of time to harden off. Starting high light requirement plants in a windowsill will usually cause extensive stretching to the point that they may not hold themselves up upon maturity. I recommend starting under LED lights before I would recommend starting in a window. They stay much more compact under artificial lighting.