Growing and caring for Ranunculus
The flower name ranunculus comes from the Latin words ‘Rana,’ which means frog, and ‘unculus,’ which means little. But no one calls these flowers little frogs today. You probably know them as buttercups.
What Is a Ranunculus?
Ranunculus grown in gardens or purchased as cut flowers are usually varieties of Ranunculus asiaticus, also known as Persian buttercups. The original species is native to southeastern Europe and parts of Asia.
Types of Ranunculus
Ranunculus colors range from white to red, pink, yellow and orange, and all shades in between. They’re considered tender bulbs, hardy in U.S. Department of Agriculture Plant Hardiness Zones 8 through 10.
For those in USDA Zones 7 and colder, ranunculus are grown as cool season annuals because they go dormant in temperatures hotter than 75 degrees. The bulbs — actually tubers — can be dug up once dormant and stored for re-planting the following spring.
Depending on the variety, ranunculus can range from one to two feet high. Taller ranunculus may need to be staked or secured, because their big, rose-like flowers can be prone to flopping.
How To Plant Ranunculus
Where ranunculus are hardy
If you live in Zones 8 through 10, plant ranunculus tubers in the ground in the fall. Choose a location with full sun and well-drained soil.
When you first buy the tubers, they’ll look dry and shriveled. Some say they resemble tiny octopuses or the claws of a bird. Soak them for a few hours in room temperature water and they’ll plump up and be ready to plant outside. Plant about two inches deep with the claws pointing down, about three to six inches apart.
If you pre-soaked the tubers, they should sprout in a few days and bloom in approximately 90 days.
Where ranunculus are not hardy
If your winters are too cold for ranunculus to survive in the ground, plant them in spring.
Decide when you want your ranunculus to bloom, then count back 90 days to determine when to plant. Before planting, soak the tubers for a few hours in room temperature water, then plant in containers or pots. Put them in a cool location where temperatures will stay above freezing, like a cold frame.
Some gardeners like to pre-sprout their ranunculus tubers before planting. To do this, soak them for a few hours, then lay them out on a flat planting tray filled half-way with clean potting soil. Cover with more potting soil and keep in a cool location. The tubers will sprout new, white roots. At that point, you can pot them up to continue to grow.
Only plant ranunculus in the ground when there is no possibility of temperatures below freezing.