If you've mastered the prayer plant, and looking for a plant similar but with more intricate leaf design and a step up in difficulty, Calathea is your plant. Calathea Medallion is a more common variety, both attainable and easier to care for than many other in the Genus.
Calathea are a ground cover Tropical plant with vibrantly colored oblong foliage. The leaves can reach up to 24" long and 10" wide on some varieties, but the plant itself rarely grows larger than 36" tall and 36" wide. Your Calathea can likely be grown in it's 6" grower pot for years to come, and when it outgrows the container you can transplant into a container 2" wider, or split your Calathea.
Calathea are considered an intermediate plant in regards to its care. The leaves crisp around the edges, curl, or deform when they dry out for too long. Calathea perform best in High humidity and damp conditions. Be sure to keep your Calathea humid, using a drip tray with rock and water, a mist bottle, a humidifier or any other means. Water your Calathea regularly Spring through Fall, watering every time it dries out. And water slightly less often in the winters. Calathea are a magnet for Brown two-spotted spidermites. With that in mind, keeping the higher humidity around your plant will help keep it healthy and growing well, but also discourage spidermites from sticking around. Calathea are almost a "Canary" in a coal mine. Check them regularly to be sure your home is still pest free.
Transplant your Calathea using a Tropical Soil Mix, to hold moisture slightly longer than a traditional soil mix and avoid terra cotta planters when possible.
We use Schultz all purpose fertilizer throughout the growing season, and stop fertilizing entirely for the winter months. You should be feeding regularly, every to every other watering, directly into the soil. Avoid foliar spray fertilizers and leaf shines, as Calathea are slightly delicate in regards to what product they have on their leaves.