Growing Ranunculus

The beautiful ranunculus can be a very difficult crop in zones with short springs and large temperature swings.  Follow along with these steps to get the best blooms in May and June.

Ranunculus is native to the Mediterranean. A good starting point for growing is understanding the native climate. The key here is COOL spring temperatures and well draining soil. In our zone 5, corms should be presprouted in late January. They need a full 90 days to start putting on blooms.

Corms are soaked for a few hours and placed into a tray of moist (not wet) soil. Sprouting temperature should be 50-65°. Sprouts and roots should appear in 10-14 days. From this point, they can remain in trays under lights for the next month as vegetative growth and root structure starts.

A month in, plants should be potted up. Spacing recommended at 6”. There are a few options here-

In ground: covering is highly recommended, whether a simple hoop cover with frost cloth/plastic, or a blanket — covering when night time temps dip into the 20°s.

Bulb crates: this is how we grow them. Bulb crates can be made into a mini raised bed. You can often get them from your grocery store or on Facebook marketplace. The benefit of bulb crates is the ability to move them inside a garage or shed on a cold night. You can fit 8-12 plants per crate.

In pots: Pots are a great way to grow ranunculus. You can control the soil and sun and move or cover them when necessary. 8” depth is recommended.

Ranunculus like well draining soil. We use a high quality potting mix and add extra vermiculite or perlite. Water regularly. Letting them dry out will stunt growth. Apply a liquid fertilizer every week or two for continuous blooms.

Ideal growth is 8-12 hours of sunlight, 65° days and 45° nights, but they can handle cold all the way down to 25°. They will go dormant once temperatures are consistently in the mid 70°s to 80°s. If you want to save your corms, stop watering, and let the leaves die back. Place the corms in an open dry place (garage works well) until fully dry and store in a paper bag until next season.

We hope you have fun with this plant. They are a bit tricky, but the reward can be spectacular!