Growing Ranunculus on the Canadian Prairies


Certain flowers seem to be a must for us. Ranunculus is one of them. The multiple petals of the blooms are truly like nothing else. The only downside is they don’t last all summer.

Many years ago I tried growing ranunculus. I followed the back of the package which essentially told one how deep to plant the corm. I was disappointed when not one grew. After a couple attempts I gave up.

A few years back I decided to try my luck again. Using a different method altogether I now have succeeded. Our initial 40 corms we started with a few years ago now number over 130.

Ranunculus are a cool season flower. We start ours around mid March (or when our unheated garage is consistently 10 degrees Celsius). They get planted into the garden mid April.
They can handle -5 degrees Celsius but begin to fade once we hit the hot temperatures of July. They fill the gap between the tulips and our heat loving flowers.

Dry Ranunculus Corms

When you first receive your ranunculus corms they don’t look like anything that could possibly produce a flower. They look like a dried up brown octopus.
The first stage is to soak the corms for 4-8 hours.

Rehydrating Ranunculus Corms

Some say you need the tap trickling to keep the water aerated during this process. I simply change the room temperature water every 30-45 minutes.

Digging up at Seasons End

The corms are sufficiently soaked when the legs take on a tan look and are twice the size.

Ranunculus Corms Ready to Pre-sprout

Once the corms are rehydrated, prepare a tray of soilless mix, vermiculite, or potting soil (I’ve used all three for this stage).
Place the corms in legs down into an inch of soil. Use care as those little legs can be fragile. Cover with an inch of your soil and place the tray in a cool dark place.
A temperature around 10 degrees Celsius is perfect. We put ours in the garage. Keep the soil moist, not wet.

Pre-sprouted Ranunculus

Pre-sprouting takes 10 – 20 days. When the corms have developed tiny white roots it is time to pot them up and bring them into the light. A Sunny south facing window or under a grow light will work.

Frost Blanket for Ranunculus

Once outdoor temperatures in the evening are consistently around -5 Celsius you can plant out the ranunculus. Be sure to harden them off first. Should temperatures dip, cover them with a frost cloth

Using one large bloom as the thriller and smaller as the filler

Ranunculus make a great cut flower. Harvest the blooms by cutting the stem at the base of the plant and place immediately into water. Strip off the lower leaves when making a bouquet. These beautiful blooms will keep for 7-10 days if you change out the water every few days.

Sorted and Prepared For Drying

One should expect to get 6-7 weeks of blooms. Once the days warm to 26 Celsius the plants will begin to go dormant. Allow the plants to die back. At this stage energy is being saved by the corm for next year.

When the plant has died back dig up the corms and dry them in a dark place with good ventilation. we place ours in planting trays.
After a day or two you should be able to carefully separate the new corms that have developed. I find rocking back and forth gently works the best.

Once dry place the corms in a mesh bag or paper bag and store in a cool dark location such as a cold room.

Why not try them, you will be happy you did.