Grow ranunculus plants in pots by planting them in 10-inch containers, using well-drained potting soil, watering them regularly and placing them in a location with exposure to full sunlight. Mulch the plants to keep the soil moist, and remove faded flowers to encourage growth.
Fill a 10-inch pot with well-drained potting soil with a pH of 6.0 or 7.0, and mix in bone meal and fertilizer or organic matter. Place two to three tubers or bulbs, depending on the size of the pot, in 2-inch deep holes with the claws pointing downward. Water the bulbs, and place them in a cool, sunny location. Spread a 3-inch layer of natural mulch such as cocoa bean hulls, straw or bark over the bulbs to keep the soil moist. Water the plants regularly from the base only once the tubers sprout, and avoid wetting any foliage and flowers.
Regularly deadhead the flowers to prolong the blooming period. After the flowers stop blooming, cease watering them. After the foliage dies down, remove and store the bulbs for spring planting, or bring them indoors. Do the latter during the winters in wet, cold climates, and place them in a west- or south-facing window with an average inside temperature of 55 to 68 degrees Fahrenheit.