When I first saw the gorgeous blooms on ranunculus flowers, I didn’t think it was possible to grow them here in the low desert of Arizona. I’m glad I was wrong. Learning how to grow ranunculus is easier than you think.
The stunning rose-like blooms with tissue-thin petals almost don’t look real. Ranunculus blooms come in nearly every color on tall stems. Learn how to grow ranunculus (even if you live in a hot summer climate like the low desert of Arizona) with these 5 tips.
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5 Tips for How to Grow Ranunculus
1. Plant ranunculus at the right time
Ranunculus grows best in spring-like temperatures of about 55°F with plenty of sunlight.
In zones 7 and warmer, there are two planting windows — late fall and again in late winter or early spring. For zones cooler than zone 7, plant in the spring after danger of frost is passed.
In the low desert of Arizona, plant ranunculus corms from October – November and again from February – March.
2. Soak corms before planting
Ranunculus are grown from claw-like ‘corms’ — a swollen underground plant stem that stores the nutrients for the plant until needed. Look for large corms as they have more stored energy, and will grow larger and have more blooms.
Soak the corms in tepid water for 3 to 4 hours (not longer). The corms will absorb the moisture and often double in size.
3. Plant ranunculus correctly
Ranunculus grows best in rich, healthy, well-draining soil with plenty of sunlight. Add several inches of compost and a balanced organic fertilizer to the soil before planting.
Plant corms 2-3 inches deep and about 6 inches apart. Place ranunculus corms in the ground with the claws facing down. Fill the hole back in with soil, and water well. Do not water again until sprouts appear above ground.
For square foot gardening, plant 4 corms per square foot.
4. Care for growing ranunculus
Overall, ranunculus is an easy plant to grow and it’s fairly pest and disease resistant.
Ranunculus needs plenty of sunlight to grow well. Ranunculus grows best in moist soil, but does not like overwatering. If soil is not well-draining, ranunculus corms often rot.
SPECIAL NOTE: All parts of ranunculus are poisonous when ingested. The plant sap may cause skin irritation. Poison is not residual in the soil, only the plant is poisonous.
5. Enjoy ranunculus blooms
Corms planted in the fall typically bloom for about 6 weeks. Spring-planted corms bloom for about 4 weeks, depending on the weather. Once temperatures heat up, the blooms will stop.
In the low desert of Arizona, you can expect blooms to begin in February for fall-planted corms and continue through May for spring-planted corms.
Deadheading plants encourages more blooms. For cut flowers, cut stems just before buds open for the longest vase life.
When blooms finish and the leaves begin to yellow and die back, cut foliage off and stop watering. Allow the corms to dry out and go dormant. If desired, dig up dormant corms and store in a cool, dry place until it is time to plant next season.
Just love the look of the flowers! Thank you so much for explaining how to grow them. I am really enjoying my calendar that I recently bought from you! Just moved to Phoenix and wanted to know if there was a nursery to buy these little bulbs or where do you get yours from.
Thanking you for all you wonderful teaching!
Hi, Welcome to Arizona! I purchased my corms in the fall from Easy to Grow Bulbs online. I’ve purchased transplants in the spring from Arcadia Color Garden, there may be other nurseries that have them as well.
Thank you!
Hello, it appears Arcadia Color Garden went out of business like the day after you posted your message above! Do you know of another ranunculus plant supplier?
So sad that they are gone. I saw some potted up at Home Depot. You could also try Summerwinds nursery or A&P Nursery.
Go to direct gardening they have 30 corms for just under $7 https://www.directgardening.com/285-bulbs/5173-ranunculus-mix#/quantity-30
I planned some ranunculus on a pot, after I’m done can I use the same pot and soil to plant some veggies I was reading in Google that ranunculus are actually poisonous?
You’re right, all parts of the plant are poisonous. The poison is not residual in the soil and it is safe to plant something else in the pot or edible plants near ranunculus.
It looks like a lot of places don’t ship the corms till after our planting time is over for spring. Can I order online now and save them for the fall?
That’s not a bad idea. It’s tough to get them at the right time to plant.
Question about letting ranunculus go dormant. If I’m using the garden grid system and cant turn water off to the section would I just cut foliage when time then dig up corms with some soil and place somewhere to dry out? I’m probably overthinking it. Thanks!
That’s what I did.
how do you store your corms before planting. I ordered some and they are sending them sooner than I expected and it is too hot to plant them. While I wait for the temperatures to dip what do you recommend?Thanks
The ones I pulled up earlier this year and the ones I purchased this summer are in paper sacks in a hall closet. I may even put them in the fridge for a few weeks before I plant to vernalize them a bit.
do you soak them before or after refrigerating?
Soak them just before planting.