yellow and dropping leaves

[bigblue]

Hello all,

Wondering if anyone can put a finger on this. I potted these up to 4” x 4” x 4” pots about 4-5 weeks ago. They are in Miracle Grow “Organic Choice Potting Mix”. After a initially not feeding them I was advised to/and have been feeding them ½ strength Urban Farms Vegetable fertilizer. All has been going well they perked up and for the last 3 weeks I have had them for a few hours each day in the window in direct sun. About 4-6 days ago the lower leaves started getting yellow and dry. The plants still look healthy on the top. I am watering only once a week (and feeding) so the mix is quite dry before they get watered (but don’t wilt). I don’t think they are over watered. Maybe not enough fertilizer? I am puzzled.