Garden Friends, today I want to talk about how to grow ranunculus flowers. One of the best fresh cut flowers, is the ranunculus. Ranunculus flower is a cold loving perennial flower and when temperatures start getting about 70 degrees consistently they are done for the season. The ranunculus is a multi-layer flower that come in many colors pink, yellow, orange, blush, red and white just name a few. Ranunculus are good flowers for containers and flower beds. Ranunculus have a long vase life and is an excellent cut flower.
Ranunculus do best in regions with mild winters and long cool spring weather. Fall is a good time to plant ranunculus if you live in one of these regions. The areas with colder regions like me in Michigan, late winter or very early spring once the threat of hard freeze has past or create a small hoop cover or caterpillar tunnel for them until the threat of freeze has past. Ranunculus can grow well in zones 3 thru 10 but will need to be lifted in zones 3 thru 7 and stored for the winter. They are winter hardy for zones 8 thru 10.
Pre-Sprouting Ranunculus Corms
Ranunculus sometimes are refered to as bulbs but they are actually corms. It’s uniform undifferentiated structure composed of stem tissue for the sole purpose of storing food for the next season. Before pre-sprouting ranunculus corms they need to soak in room temperature water for 3 to 4 hours, no longer then that because they may get too mushy, rot and not grow.
Corms like to be re-oxygenated during their soaking. There are several ways to do this, the probably most expensive (but really, probably under $20) is to get a bubbler for a fish aquarium with a 5 gallon bucket, put the corms, each variety in its own mesh bag, with a label (so you know what they are) and add them to the water. The easier way is to get a few different containers with room temperature water in them and either change the water every hour or just take your finger and stir up the water. I have watched several YouTube videos, and most say neither is needed but they all do something to aerate the water.
Once the corms are done soaking, they will double in size and look a little like an octopus. Doing this gives the flowers a headstart in growing these awesome flowers. Another way to give them a headstart is pre-sprouting ranunculus corms. You can get seed starting cells and fill them with pre-moisted seed starting mix or potting mix. You can just add enough water to the soil to get it moist but not soggy.
Place corms on top of the moist soil and cover them lightly with more moist soil. Place them in a 50 degree place like a cool basement/Michigan basement, somewhere they won’t get too warm. Check them every couple days, and after 10 to 14 days, the corms should be sprouted. When you see white roots they are ready to plant either in containers indoors or if your wealther allows to plant in the ground. They will be ready to plant outdoors if the temperatures are not too cold 50 or 55 degrees or plant indoors in larger containers until they can go outdoors.
Starting Ranunculus indoors
When starting ranunculus indoors or outdoors, you would do the same thing when prepping, soaking and pre-sprouting. When starting indoors, living in a cold climate, the best time to start them indoors is 3 months before your last frost date. Once the pre-sprouting is done, you will need to find containers. When starting ranunculus indoors you will need to find a place for them, preferably in an east facing window and cool spot. They can also go in an unheated sunporch that can be in the high 20’s to 30 to 35 degrees. Some of the flower farmers in the YouTube channels have had ranunculus in temperatures down to 10 degrees and they still did fine.
Ranunculus don’t like to dry out, so keep them moist but not soggy. If the ranunculus get the appropriate water they will do well as long as they are not near a heat source or draft. In colder areas like in Michigan, where we dip into freezing temperatures for long periods of time, they can stay indoors or move to a hoop house or low tunnel, caterpillar tunnel for protection.
Planting Ranunculus Outdoors
Ranunculus like a sunny spot with well draining, rich soil. If the flower bed is prone to puddling, you will want to redirect the water to not waterlog the plants. Ranunculus like the sun but not the heat. The soil level can be added to help with drainage by using 2 to 3 inches of compost. organic matter or peat moss. When planting ranunculus outdoors you will want to take this information into consideration when planting outdoors.
Ranunculus corms have pointed ends that look like claws. When planting outdoors, the claw-end is facing down when you plant them. Plant them 1 to 2 inches deep and 4 to 6 inches apart. Water well after planting, and add 1 to 2 inches of mulch to help retain moisture that is needed for the plants early growth. The flower growth will appear in about 90 days. Again if you are in zone 8 thru 10, you can keep the corms in the ground. To insure they come back the following year, make sure they have a very well drained soil. Corms are prone to rotting when they get to wet.
If you are in a zone 8 thru 10, they can be planted in the fall and will start blooming in early spring and flowering continuously for 6 to 7 weeks. If you are in zone 3 thru 7, plant them in late winter to flower by mid-spring and usually will remain blooming for 4 to 6 weeks. If you plant the ranunculus outside and there is a frost or freeze danger, cover with a frost cloth for protection,from what I have learned they can take quite a bit of cold. Ranunculus need to be deadheaded as flowers begin to die off, cut them right at the base to encourage more blooms.
Ranunculus flowers are a great cut flower as they have a vase life for about 10 days after they have been cut. Ranunculus are great for fresh cut flower bouquets. They grow 12 to 24 inches in height. The key to keeping ranunculus is to cut them properly. Cut them when they are still a bud and not fully open. This will allow them to stay in a vase for over 10 days. When the buds have color and are still squishy like a marshmallow, it is a good time to cut them. Cut the flowers at the base with sterile sharp scissors. If you cut the flowers after they are open the vase life is about 7 days.
Earlier in this post I talked about ranunculus flowers in zone 3 thru 7 they will need to be lifted or treated as an annual. If you decide to lift them to try again the following year, here is what you do. It is best to wait for them to be done blooming and die off by themselves. When the top half of the plant has started to die, cut right down to the crown of the plant. By letting the ranunculus die back on their own, it will be able to store enough energy for next season. Remove the corms from the dirt either by hand or a small shovel, remove the majority of the dirt. We don’t want anything left on the corms that can produce moisture and rot the corm. Let the corms dry for 24 to 48 hours and place them in a paper bag and label them. Then store them in a cool dry place like your basement, anywhere its a cool dry place
Purchasing Ranunculus Corms
The best time to order corms is in the late summer for the best selection and will deliver in the fall. Always get the largest size available, 2 to 3 inches (5 to 7 cm); they will produce more abundantly and the flowers will be larger. The bigger corms will give 10 to 12 stems in a growing season as the smaller ones, 1 to 1 1/2 inches (3 to 4 cm) will produce only 5 to 7 stems. I have purchase corms from Eden Brothers, Amazon, and a few other places. You can also purchase at your local garden center either corms or plants.
I love ranunculus flowers and if you are interested in purchasing some corms, check out Eden Brothers or the Amazon link below. Eden Brothers are pre-ordering for spring 2022 and delivery depending on your zone. I have purchased from both. I have been watching quite a few YouTube channels about Ranunculus and found the most updated information from Flower Farmers all over the US and in my zone. If you have never grown ranunculus, I encourage you to try. These can be planted in the fall as well when the temperatures start cooling off, you can follow the same process but plant in the ground when the temperatures are under 70 degrees and plant them again in the spring.
Please leave me a comment and let me know if you have grown ranunculus before? Did you have success or failure? They can be a little tricky but not too bad. If you have grown them what colors or varieties did you grow?