slide you some relective material between the soil and wire mesh.

assume you have a little room to move it in and out for watering through veg then left alone due to hose watering.

cut some mylar to 14x14
cut one line half across
placed ontop of 12qt pots like a square pacman

no soil light loss
no light loss below the rims

light being reflected back up is lighting up those 2ndaires.