The ranunculus, a cold-hardy perennial, is known for layer upon delicate layer of vibrantly colored, paper-thin petals. Growing 12 to 24 inches tall with a 6- to 12-inch spread, ranunculus plants sport grass-green foliage and 3- to 10-inch wide blooms in a vast array of shades. Ranunculus flowers grow from tubers, shaped like a minuscule bunch of bananas, divided into four size classes, including jumbo, No. 1, No. 2 and No. 3. Whether planted individually, in decorative containers or in dramatic mass plantings, ranunculuses add extraordinary beauty to any landscape.
Choose planting locations that offer well-draining soil and full sunlight. Equal amounts of coarse sand and organic compost can be worked into the planting site to improve drainage, especially for clay soil types.
Wait to plant ranunculus tubers until 1 to 2 weeks before the last frost for colder climates with harsh winters. In warmer climates, bulbs can be planted in late fall for late winter/early spring blooms.
Make a 1- to 2-inch hole and place the ranunculus tuber in with claws (resembling a bunch of tiny bananas) pointing down. Once the tuber is situated properly, cover with a thin layer of soil.
Space tubers according to type. Jumbo tubers should be planted 8 to 12 inches apart, while smaller tubers need only 4 to 6 inches of space.
Water tubers thoroughly to set, then cover with a 2- to 4-inch layer of mulch. The National Gardening Association recommends bark, straw or coco hulls.
Wait until sprouts appear before watering again. Germination typically takes 15 to 20 days.