[Gardening] stuck starts?

Hi all - great new list! I started many flower seeds in the usual plastic flats, and have transplanted them in the ground. But probably due to some days of shaky childhood as sprouts (not great light, and a cold spell), they seem stuck -- into their second week now, and staying small, healthy appearing, but not growing. Any advice to give 'em a kick start? I've cared for the soil, neighboring plants are doing great, and last year's did well - so I don't think it's that. Thank you! Rick (King Charles Rd)