How to Grow Ranunculus
At the height of their beauty, ranunculus blooms resemble that of a rose, with vibrant shades of cup-shaped, tissue paper-thin petals. The blooms of ranunculus are a far cry from the appearance of the corms they grow from. The popularity of these blooms and the relative ease of growing them makes them a great addition to any cut flower garden. We're happy to pass along some of our best tried-and-true tips on how to grow ranunculus.
Are Ranunculus Annuals or Perennials?
Ranunculus flowers can be either annual or perennial, depending upon the zone in which they are grown. Gardeners in zones 4-7 (including us here at Wheels 2 Fields Flower Farm) cannot expect our corms to survive in the ground over the winter months. Instead, we store our dried corms until late January or early February and replant them each year. In growing zones 8-11, most ranunculus species can successfully be treated as perennials.
How to Plant Ranunculus Corms
Ranunculus Corms are not pretty. They look oddly reminiscent of dried octopus and, yet, like the ugly duckling, they transform into beautiful blooms.
Here at Wheels 2 Fields Flower Farm, we store our dried ranunculus corms until early February, at which time we gently go about the process of "waking them up." We start by soaking them in a lukewarm bath for about four hours. It's important to soak them in a spot that either allows for a dripping faucet or a fish tank aerator to circulate the water. Allowing ranunculus corms to soak in stagnant water can lead to disease.
After the soaking period, ranunculus corms become plump and ready for either pre-sprouting or direct planting. We opt to pre-sprout and are rewarded with an earlier blooming time. To pre-sprout your ranunculus corms, you need to evenly space them in a shallow tray of potting soil. Ensure that the corms do not touch one another to reduce the risk of mold. Lightly cover the corms with high-quality potting soil and give them a sprinkle of water. Then, loosely cover the trays, making sure to allow a slight opening for air to circulate. Store the trays in a cool, dark space. We store ours under the basement stairs. Every few days, check the trays. Keep them moist, but not wet. Watch for signs of mold. If it begins to form, the trays are too wet. Any corms that show signs of mold should be removed and discarded.
The pre-sprouting period should last about ten days. During this time, the corms will double in size and develop 1" roots. Depending upon the temperature of the room, they may also begin to sprout. In growing zones with low temperatures of 15° - 20° Fahrenheit or warmer, the revived corms can be planted outside with minimal cover. We plant ours 8" apart and about 1" deep in rows and then cover them with caterpillar tunnels.
All About Ranunculus Blooms
Ranunculus will begin to bloom at around the ninety day point. These flowers have an excellent vase life; you can expect them to last up to ten days when properly maintained in a bouquet or arrangement.
As with any cut flower, you will maximize the longevity of your ranunculus blooms if you keep them in clean, room temperature water and refresh the water every couple of days or when it begins to look cloudy. Store your flowers in a spot away from direct sunlight. You may also use plant food or a teaspoon of sugar dissolved in the water with a couple drops of bleach.
Ranunculus flowers have a special place in my heart. My dad and I once visited The Flower Fields at Carlsbad Ranch in California. At that time, they grew nearly fifty acres of Giant Tecolote Ranunculus. The entire hillside was covered in a rainbow of the most gorgeous blooms. I'm sharing a picture of what we saw firsthand.
I hope these tips equip you with what you need to know about how to grow ranunculus. These really are some beautiful flowers