Layers of papery thin ranunculus petals form beautiful, exquisite flowers 3 to 6 inches wide on top of 12- to 18-inch stems. Yellow, orange, red, salmon, gold and white are just a few of the colour choices and the flowers can bloom for up to six weeks. Ranunculus are an excellent choice for the garden but can also be grown in containers.
Fill your planting container with potting soil, packing it down lightly as you go, to within 1/2 inch of the rim. Plant each tuber with the claw-like end pointed down 2 inches beneath the soil level. Space the tubers 4 to 5 inches apart.
Water the tubers thoroughly and stop when the water drains out the drainage holes. Apply a mulch.
Set the containers in a sunny location. Don't water again until you see new growth, usually in about 15 to 20 days. At that time and thereafter, water to keep the soil slightly moist.
Cut the ranunculus back after they are finished blooming and the foliage has turned brown or yellow and died back. Stop watering and bring the containers to rest in a cool location such as a basement or garage. Bring them back out in about three months, when they may bloom again.
Choose containers that are at least 10 inches wide. Ranunculus have large root systems and need lots of room. You can plant one or two jumbos or three "number two" tubers in a 10-inch pot. Make sure there are several drainage holes in each container. In U.S. Department of Agriculture Plant Hardiness Zones 8 through 11, plant ranunculus in October or November, for flowering in March. In Zone 7 and further north, plant them a week or two before the typical last frost for flowering in the summer.
Many gardeners throw out their tubers once they have bloomed and start over with fresh ones. Ranunculus are not always reliable perennials, whether planted in a garden or in containers.