light
Calathea prefer medium light and do tolerate low light conditions. Direct sun may cause leaves to burn.
soil
Plant in an all-purpose potting soil, or up your game with a maranta specific mix made up of 2 parts peat moss or coco coir, 1 part all-purpose potting mix, 1 part perlite, and 1/2 part charcoal.
water
Keep soil evenly moist, but not saturated. Never allow to sit in standing water.
fertilizer
Feed every two weeks with an all-purpose fertilizer during the growing season; April through October.
tips and troubleshooting
Calathea can suffer from leaf curl, browning tips, and leaf drop. All of these problems can usually be attributed to low water and low humidity. Check moisture levels often and increase humidity if necessary. Terrariums, cloches, or domes are an option too.