Ranunculus is a genus of herbaceous perennials consisting of about 400 different species, including buttercup, spearwort and water crowfoot. They are typically grown as annuals in most locations, as the tubers cannot tolerate freezing temperatures. Ranunculus can reach 10 to 14 inches in height, and produces flowers in a variety of colors in early spring through summer. Plants are easy to care for and require only minimal maintenance once established.
Plant ranunculus tubers in spring after all threat of frost has passed. Select a planting location with full sun and rich, well-drained soil. Dig a planting hole about 2 inches deep, place the tuber inside with the clawed side facing down, add a handful of sand and fill the hole with soil. Space plants 6 to 8 inches apart.
Water ranunculus tubers thoroughly just after planting and continue watering once every 10 to 14 days to keep the soil barely moist until foliage emerges. Increase watering to once per week after growth appears and continue until late fall when foliage dies back.
Apply a 2- to 3-inch layer of mulch to the ground surrounding ranunculus plants just after planting and watering to keep the soil moist and prevent the bulbs from drying. Peat moss is the recommended mulch for ranunculus, but bark mulch may also be used.
Feed ranunculus plants once per year using a balanced flower fertilizer. Apply fertilizer according to the manufacturer's instructions in late spring, or as soon as new growth emerges. Water thoroughly before and after apply fertilizer to prevent nitrogen burn.
Dig ranunculus tubers from the ground in late fall, before the first frost of winter. Ranunculus will not survive winter temperatures in most locations. Store the tubers in peat moss in a cool, dark location. Replant in spring after all danger of frost has passed.