Ranunculus corms resemble little, strange octopus. It’s best to soak them in tepid water for 3-4 hours prior to planting. Don’t over soak the corms, or they could rot. In Zones 7 and above, they can be planted throughout the spring. In colder Zones, ranunculus should be planted outside after all danger of frost has passed. For an earlier start, pre-sprout the bulbs indoors in a seedling tray filled with a standard potting soil. Cover the soaked corms with potting soil, water well, and keep the tray in a sunny window. Check the soil every few days to make sure it’s moist but not soggy. The corms will swell and produce white roots. Place outdoors after the danger of frost has passed. Plant bulbs with the ‘tentacles’ facing down.
Plant bulbs 2-3 inches below the soil surface and space them approximately 9 inches apart.
Ranunculus prefer a rich, well-drained soil. Amend the soil with a thick layer of composted organic matter dug in to the top 6-8 inches of ground.
Plant in full sun, or in regions with hot summers, plant in partial shade.
For best results, fertilize monthly with an all-purpose fertilizer.
Ranunculus blooms have a very long vase life of up to 10 or more days. Harvest the flowers when the buds are colored and soft but haven’t fully opened. Add floral food to the vase water. Keep the plants dead-headed to maximize the bloom time.
End of Season Care
In Zones 7 and above, leave ranunculus in the ground and cover with a protective layer of mulch. Leave the foliage on the plants to help nourish the bulbs. In Zones 6 and below, dig the bulbs before the first frost and let them air dry for several days. Store bulbs in peat moss in a cool, dry location. If you are unsure about overwintering the corms in the ground, the safe bet is to dig them up and store them until spring.