Curious about these beautiful spring flowers, but not sure where to start with growing ranunculus flowers? Don’t fret, we’ve made all the mistakes so you don’t have to! This quick start-ranunculus guide is great for ranunculus first-timers and experienced growers alike.
Skip to sections:
- Why to Grow Ranunculus Flowers
- What is a Ranunculus Corm
- Where to Buy Ranunculus Corms
- When to Start Ranunculus Corms
- How to Grow Ranunculus Plants
- Harvesting Ranunculus Flowers
- What Not to Do
- Which Ranunculus Varieties to grow?
Why should you Grow Ranunculus Flowers?
Ranunculus flowers are very rewarding to grow, they’re beautiful spring-time blooms that push out stems over many weeks. Once you know the tips and tricks, and what not to do (hyperlink to anchor of that section), they’re pretty easy to grow, making them well worth the garden space and effort. For warmer climates that can’t grow peonies (like where we are in North Florida), ranunculus are a good alternative. (I like to think of ranunculus flowers as a thornless rose alternative as well.)
In arrangements, when harvested properly, ranunculus flowers have an excellent vase life. They work well as a standalone flower in a bouquet bubbling over with just ranunculus stems or when paired with other complimentary spring-time foliage and flowers like anemones, eucalyptus, veronica and ferns.
Top 3 Reasons to Grow Ranunculus Flowers
- Long vase life of 10+ days
- Abundant flower production
- Easy to grow (with the right technique)
What are Ranunculus Corms?
Many flowering plants grow from bulbs, corms, rhizomes or tubers. They’re all essentially stores of energy that your new plants will emerge from. Ranunculus plants grow from claw-like corms. They look weird, almost alien. These shriveled hand-like corms come in various sizes, but all will push out a ranunculus plant when properly soaked, planted and cared for. Corms can be saved and replanted year after year, or treated like an annual and tossed after the growing season has ended. (This is what we do, we don’t save our corms year to year).
How can you tell if a ranunculus corm is healthy?
Your corms will come dry and ready to store until planting time. When you receive your ranunculus corms make sure to look them over to ensure they’re healthy. There might be a big gap in time between when you receive your corms and when you plant them. Healthy ranunculus corms will be dry and firm, free of signs of black fingers or rot. They should not be mushy. You might see some white/light grey fuzz at the top of your corm (the non-finger side) which is completely normal. If any of your corms seem to have rot, take a photo/video and reach out to your supplier immediately with your concerns. Otherwise store them in a dark, dry and cool place until it’s time to plant.
What size ranunculus corm is best?
Any size ranunculus corm that is healthy will produce a flowering plant for you. Larger corms should produce more flowers and be hardier than smaller corms, but don’t be dissuaded from planting smaller corms. Expect to pay more for bigger corms.
How are ranunculus corm sizes measured?
Ranunculus corm sizes are measured in centimeters, and often are just listed as numbers (for example BB 5-6 are 5 or 6 centimeters in size). The bigger the number, the bigger the corm.
Sizes you can find ranunculus corms in:
- 2-3 (Smallest)
- 3-4 (Small)
- 4-5 (Medium)
- 5-6 (Large)
- 6-7/Jumbo (Biggest)
Where to Buy Ranunculus Corms
A quick search on your favorite search engine will quickly bring up multiple places to order ranunculus corms. Etsy is another marketplace to find ranunculus corms.
If you know the varieties you’re interested in growing, that’ll limit your options to just the suppliers that carry those corms and have them in stock.
Of course we would strongly recommend shopping for ranunculus corms from Hedgehog Flower Farm! We offer a variety of vetted and curated corms that we grow ourselves with growing notes based on our experience. We keep in stock a selection of classic colors and more unique cultivars to ensure there’s a ranunculus variety available for any taste. We typically have corms available year round, with varieties changing depending on availability. We recommend ordering late summer/early fall to maximize your options.
Check out some of our in-stock and ready to ship corms. Every order comes with a complimentary growing guide!
When to buy ranunculus corms
Feel free to scoop up the corms of the varieties you like any time of year, they store well until you’re ready to plenty.
But typically you can plan on shopping for corms depending on your growing zone on the following schedules:
- Warm climate US growers, you’ll want to purchase your corms in late summer/early fall for fall planting
- All other US growers, purchase your corms in fall/late winter for spring planting
When to Start Ranunculus Corms
Trust us when we say, timing is crucial for growing ranunculus flowers. They do not handle heat well, and if you plant them too late, you will get few, if any flowers, on short, wimpy stems. If you start them at the wrong time, you may find your ranunculus plants grow greenery, but never put out flowers :(
For US based growers:
- Warm Climate Growers - Start in the fall, and overwinter your ranunculus plants. They should be fine even if it gets below freezing. Cover with frost cloth if the temps dip below freezing to protect your young ranunculus plants. If you wait until early spring, it’ll get too hot, too soon to harvest a significant amount of flowers.
- Everyone else - Follow the generally accepted planting guidelines for ranunculus (start in the early spring) to harvest flowers through-out the spring.
How to Grow Ranunculus Plants
Before you start to grow your plants, first you MUST identify when to plant them. If you don’t plant them at the right time for your growing zone, you will not find success.
When the time is right, there are three steps to growing ranunculus: Soak Corms, Plant Corms and Maintain Plants.
Soak Your Ranunculus Corms
These shriveled claw-like corms need to be soaked in room temperature water for a few hours before planting. They’ll plump up and be ready to plant in about 4 hours.
Plant Your Corms in a Prepared Bed
Ranunculus plants are prone to rot, so they’ll need to be in a garden bed that drains well and doesn’t hold on to too much moisture. Mixing in perlite is a great way to increase draining in areas that are prone to being overly wet.
Select a site that receives full sun to maximize your flower production. In warm climates, you might opt for partial-sun with some afternoon shade or a place where you can put up shade cloth.
Don’t plant your corms too close together, that can lead to poor air circulation that causes powdery mildew, fungus and rot. We suggest 6-9” apart between corms. Plant your corms about 2” below the surface, you don’t want to plant them too deep. Plant the corms FINGERS DOWN. Imagine a claw digging into the ground. The fingers of the corm should point down, not up.
We recommend placing labeled plant markers wherever you plant your corms that include the variety name in pencil on the marker.
DO NOT WATER until you see green appear. It’s so tempting to water them too much, but overwatering will lead to corms rotting.
Growing ranunculus in containers is possible, but we don’t recommend it. The containers dry out quickly and a raised bed or in a garden bed will produce more flowers and be easier to manage.
Maintain your Ranunculus Plants
Once your plants have started to emerge above the surface, they don’t need a ton of care. Keep weeds at bay; make sure not to over water. The soil needs to dry out in between watering. We suggest proactively treating with copper fungicide if you receive a lot of rain to keep powdery mildew and other molds, fungus and mildews in check.
If you see any early blooms on short stems, cut the stem back to the ground level to encourage longer stems.
Keep harvesting flowers to encourage more and more flower production. You can fertilize with fish emulsion once in a while, about every 2-3 weeks, or just once a month if you prefer a more hands-off approach.
Need more details on how to grow ranunculus flowers (including instructions on pre-sprouting to supercharge your chances of success)?
CHECK OUT ARE CRAZY IN DEPTH RANUNCULUS GROWING GUIDE HERE
Harvesting Ranunculus Flowers
Hooray, it’s time to harvest! It’s the whole reason you grew these plants to begin with, to enjoy their flowers! Now that your ranunculus plants are blooming, you will want to either harvest regularly or deadhead regularly to encourage your plants to keep producing more and more flowers.
When harvesting for bouquets, cut your stems deep into the plant to encourage longer stems to grow. The right time to cut your ranunculus blooms is when the buds feel like a marshmallow. They will open and close during the day/evening respectively. If the center of the bud feels hard, it’s too early to cut. “They” recommend cutting once the bud has opened and closed three times. Who has time/patience to track that for each flower? Not us. Just do your best and enjoy your flowers.
What NOT to do when Growing Ranunculus Flowers
We’ve made all the mistakes, and killed all the flowers. Learn from us what not to do and save yourself the headaches:
- DON’T plant whenever you want and think the planting times are just “guidelines” for suckers. It definitely matters when you plant your ranunculus corms.
- DON’T water your corms. It’s SOOOOOO tempting to water your planted corms before they push up green. You will probably rot them if you do.
- DON’T overwater your ranunculus plants. Once you see green, you can start watering your ranunculus plants, but don’t over water. Sick ranunculus plants look dry and it’ll trick you into wanting to water too much. You will cause plant sickness and rot. Water once the soil dries out and be mindful of how much rain you’ve received.
- DON’T plant too close together. Online guides say you can plant 6” apart, you can. But we have found it better to add a little more spacing for air flow and plant health.
- DON’T forget to label where you planted your corms.
Which Varieties of Ranunculus to Grow?
We are of the mindset that you should experiment for your growing area and your personal taste to find out what varieties of a given plant to grow. What we have found to perform well for us in hot, sticky, surface of the sun Florida are the following:
- Tecolote Rose - This variety has been very care free for us, and prolific. Plus we love saturated bright colors so from a personal standpoint we really love the look of this ranunculus variety.
- Half Clone Iceberg - From a classic white flower perspective, Half Clone Iceberg is a great choice. It makes lots of flowers for us and the florists love it.
- Amandine Black - This is a great goth bloom, that looks different depending on lighting. If you gravitate towards something dramatic, we strongly recommend growing Amandine Black ranunculus flowers!
- Half Clone Juliette - If you want a traditional soft pink, perfect for spring colors, Half Clone Juliette is a sweet, romantic option.
- Any of the Super Greens - We offer a couple different Super Green Ranunculus corms, including Super Green White, Super Green Cream, Super Green Rose, Super Green Yellow and Super Green Brick. Each Super Green variety has green petals surrounded by another color of petals. They kind of look like beautiful heads of lettuce. Weird and a must-grow in our minds.
Whatever you decide to grow, you’ll probably be happier with your bouquets if you select varieties in colors that work together.
Other Ranunculus Growing Resources
We hope this comprehensive guide to ranunculus growing has been helpful. If you’re craving even MORE ranunculus goodness check out our other ranunculus resources and products:
- More ranunculus articles
- Ranunculus Print on Demand products