- How To Grow Ranunculus
- Recently viewed bulb varieties
- Ranunculus and Anemones in Zone 6b/7
- Storing Ranunculus: When And How To Store Ranunculus Bulbs
- When Do You Dig Ranunculus Bulbs?
- Additional Reasons for Ranunculus Bulb Storage
- How to Store Ranunculus
- Prolific and Terrific: Ranunculus
- RANUNCULUS Flower
- How to Grow Ranunculus
How To Grow Ranunculus
- Depending on where you live and what kind of set up you’re working with, you can plant your ranunculus in either the fall or late winter-early spring. While spring planted corms won’t be quite as prolific as fall-planted ones, a nice harvest can still be had. In areas with mild winter temps (zone 7 and above) ranunculuses can be planted in the fall and successfully overwintered outdoors with minimal protection such as a low tunnel or frost cloth. In colder areas, where temps dip well below freezing for extended periods of time, you can start them indoors—in a hoophouse or low tunnel, or in trays to plant out later—at the very end of winter. Plants can be moved outside once the threat of deep freezing has passed—this is usually about a month before your last spring frost.
- When you unpack your ranunculus corms you’ll notice they resemble little brown octopuses, and are probably not what you were expecting. Don’t worry, these strange looking creatures will actually produce an abundance of beautiful, ruffly blooms!
- Before planting, soak corms for 3-4 hours in room temperature water, leaving the water running just slightly during the process to help provide extra oxygen. As the corms soak, they will plump up, often doubling in size. After soaking, corms can either be planted directly into the ground, or be presprouted. Presprouting the corms before planting will give plants a jump start and you’ll have flowers a few weeks earlier than non-presprouted ones.
- To presprout, fill a flat-bottom seed tray halfway full of moist potting soil. Sprinkle the soaked corms into the soil and cover them with more soil so that they are completely covered. Leave this tray in a cool place (40-50° F or 4-10° C), where rodents can’t find it for 10-14 days. Check on them every few days and make sure the soil is moist but not soggy and remove any that show signs of rot or mold.
- During this time, corms will swell to twice their original size and develop little white rootlets that resemble hair. Once these roots are about 1/8- 1/2″ (0.3-1 cm) long (pull them up to check), plant them in the ground 2-3″ (5-7.5 cm)deep.
- During cold stretches, when temps dip below freezing, cover the plants with a layer of frost cloth.
- Ranunculus normally starts to flower about 90 days after planting. Fall planted corms bloom in early spring and continue steadily for six to seven weeks. Late winter planted corms will flower by mid spring and continue for four to six weeks.
- The vase life on Ranunculus is outstanding, often exceeding 10 days! Cut when buds are colored and squishy like a marshmallow but not open for the longest vase life. If cut open they still last a good week but are more fragile to transport.
Recently viewed bulb varieties
The first plants I ever grew in the lead-up to my horticultural career were Ranunculi. I was just a child then, but I’ll never forget the thrill I experienced when the first flowers began to open that spring. It comes back to me every time I see Ranunculi in bloom, but these plants have taken a fresh twist, and these days, you can get colours I never dreamed of back when I was a kid.
Growing Ranunuculi is literally child’s-play. So, if you’re hoping to set your garden up for success but aren’t sure if you have the (mythical) “green fingers,” they’re a great plant to get you started.
What You Need to Grow Ranunculi
- Relatively well-drained soil (add compost and build your beds up a bit if your garden tends to be soggy)
How easy is that? If you’d like to try them in pots, go ahead, but remember to choose a pot with good drainage holes and a good potting soil. Garden soil hardly ever works well in pots.
If you live in a place with very chilly winters, I suggest you plant your bulbs in pots and grow them in a greenhouse or cold frame, but that only applies if winter temperatures are likely to fall well below -6 Celsius once the bulbs are up and growing. Another way to get around icy temperatures is to plant your bulbs just before the final frosts of the winter.
How to Plant your Ranunculus Bulbs
My childhood Ranunculus planting was done in pure cowboy style. I put them in the ground and gave them some water. Then I made a wish. However, that’s probably not the best way to do it!
- Composting to improve soil texture is nearly always helpful to plants, so start here. As a rule of thumb, one spade of compost to three spades of soil is usually enough.
- A lot of gardeners say you should soak your Ranunculus bulbs before you plant, but it’s not absolutely necessary. They’ll absorb water from the soil after planting. They just sprout a bit faster if you put them in water first. If you do decide to soak your bulbs to kick-start growth, leave them in water for a few hours. If you forget about them, they’ll begin to rot.
- Plant your bulbs about 3-5cm deep and space them around 6-10cm apart. You’ll see that the bulbs have an eye at the top, and downward facing “claws.” Keep the claws facing downwards when you plant.
- Settle your bulbs into the soil by watering well after planting.
Caring for Ranunculus Bulbs
The great thing about bulbs is that they have almost everything they need to give you a fabulous crop of flowers already. Feeding isn’t a necessity. Just keep an eye on things when the weather is dry and give them a bit of extra water to keep them growing.
If you want to cut a posy of colourful Ranunculus flowers when they start blooming, go ahead. You’ll be surprised when you see how well they last in the vase, and cutting blooms just encourages the plant to produce even more flowers. If you want to try re-flowering your bulbs next year, cut off any dead flowers to prevent your plants from pouring energy into trying to set seeds, but leave the foliage to feed the bulb.
When the leaves have died down, decide whether you want to lift the bulbs for storage or leave them where they are. They do want to be fairly dry during summer dormancy, and you might accidentally damage them if you forget where they are, so lifting is probably the safest bet. Cut off the dead leaves and leave them spread out to dry for a couple of days.
Store your dormant Ranunculus bulbs in a cool, dry, well-ventilated place. My granny used to keep her bulbs in the pantry cupboard, but a shelf in the garage or garden shed will do just as well. Choose a cloth or paper bag or an open tray to store them in. Plastic will sweat and encourage rot. A little dry sphagnum moss will absorb any excess moisture but isn’t always necessary.
I’ll admit it: I always thought you could only get Ranunculus bulbs in mixed colours – but what colours they are! It’s as if the lustrous hues of the world’s richest gems have been scattered across the petals. But times have changed, and plant breeders in Italy have achieved the most amazing single-colour selections you’ll ever see.
Italian Ranunculus are so incredible that I didn’t believe my eyes when I first saw them. I think I gasped and let out an involuntary “Oooooooh!” and that’s me, the blasé horticulturist speaking! Farmer Gracy has selected the best of the best of these exquisite Ranunculus varieties – and you won’t be able to get them anywhere else.
The Italian Elegance® Ranunculus range sports a velvety midnight purple variety, soft pink and tequila sunrise varieties with contrasting colours at the edges of the petals, and an immensely feminine soft pink that oozes romance and makes me think of summer weddings.
These Italian Ranunculus varieties would definitely be my top choices for high-profile spots and bountifully blooming containers on the patio. And although I love my flowers for themselves, there’s something immensely satisfying about seeing a gardening buddy gasp and hearing them ask: “Where on earth did you get that?”
It’s Not Rocket Science – or Even Particularly Tricky Horticulture!
There are plants that I’m willing to beg to grow, and if Ranunculi were among them, I’d be all over them with tender care and every trick of the trade I can beg, borrow or steal. But the fact is that these vibrant beauties are incredibly easy to grow.
These days, I’m a bit more thorough than I was as a little girl who just jammed Ranunculus bulbs into the ground, added water, and made a wish, and I think my bloom quality benefits from it. All the same, the flowers continue to surprise me. It’s a little miracle. That clawed bulb is so dry and dull-looking, yet the flowers are so striking – it’s hard to believe the transformation.
Try it yourself. Planting and growing Ranunculi is hugely rewarding, and you (yes, you!) can make little miracles happen right in your home garden!
Ranunculus and Anemones in Zone 6b/7
Nothing can compare to ranunculus and anemones for spring sales, especially if you are in the wedding business! These Mediterranean natives prefer a temperate climate, one that stays cool but doesn’t get terribly hot or cold. Yeah, me too. But, alas, that’s not our climate here in Philadelphia where the winters are bitter and the summers sweltering.
When I first got into flower farming, I immediately ordered myself a couple hundred corms (the proper term for the “bulb” that produces ranunculus and anemones) and thought I’d just pop them in bulb crates in my basement in February to start and then set them outside when the spring weather warmed. That plan was a total flop. The plants were sickly, and the blooms stunted and deformed.
Anemones and ranunculus like a very long, cool establishment period to develop a robust root system and lots of foliage to support an explosion of blooms in the few months of cool spring weather around here. After several seasons of growing these beauties in zone 6b and 7, in my opinion, only those planted in the ground in the autumn and protected through the winter really produce enough high-quality blooms to make them a profitable crop. We typically have anemones starting to bloom in our hoop house in late January, and ranunculus coming along a little later when the daylight hours lengthen, usually in late February. Steady production for sales runs from March to May. This year’s been a bit different thanks to the intensity of the winter cold, but this hopefully isn’t the norm. Hopefully.
A hoop house is very handy to have when growing anemones and ranunculus. But even if you don’t have a hoop house, you can still produce a lovely crop of these flowers with some carefully engineered low tunnels (or “caterpillars”) out in the field. The low tunnel concept was originally popularized by Eliot Coleman for winter veggies, but low tunnels work just as well for flowers. It took a couple (frustrating) years to figure out how to build these to withstand fierce wind and heavy snow. We finally have the formula down and our low tunnels can take just about anything.
We build these inexpensive structures with half-inch metal electrical conduit from Lowes, a hoop bender, greenhouse plastic, tomato twine, and Agribon fabric. If you’re a subscriber to Growing for Market, there was an article a few issues back about how Tony at Bare Mountain Flowers builds his. Tony is a wiz at building and inventing. We based our design off his and then tweaked it with metal hoops and a few other adjustments to withstand our heavy snows. We’ll be demonstrating how to build low tunnels at some of our workshops this spring.
A great rule of thumb for any crop is to think about ordering for next year when the current season’s crop is finishing up. Therefore, anemones and ranunculus corms should be ordered in early summer. My favorite supplier is Gloeckner. They are a large wholesale supplier with high minimums. If you want to try a small batch first before committing to a big crop, a quick online search will yield several retail suppliers for ordering smaller quantities.
For ranunculus, I’m especially fond of the Le Belle series for our climate here. We’ve also been trialing the Amandine series in smaller quantities over the past two seasons. This series has been bred to withstand a bit more heat before going into dormancy in May or June. However, it seems this breeding has made it harder for Amandine to grow as well through the cold of the winter months so the plants are weaker than the Le Belles overall. Therefore there’s been no increase in production by having a longer harvest window. Amandine does seem to be coming up with some unique colors though so we’ll keep trying them.
For anemones, we’ve had great success with the Galilee series. This series has the ever-popular white face with the black eye, sometimes called the panda anemone. The plants are super productive, amazingly tough, and the stem length is outstanding at 18 inches plus. We’ve also grown the Jerusalem series in the past but have since switched to Galilee entirely as the plants are just so tough and productive.
Planting of both anemones and ranunculus ideally takes place in the first half of October but can happen as late as mid-November for abundant spring blooms in our region. We soak and pre-sprout the corms per the directions sent by Gloeckner with the order.
If you’ve been following along here on the blog, you already know we’ve gone through several intense “polar vortex” spells this winter, making it one of the coldest and snowiest on record. The temperatures routinely dipped to the single digits and the wind chills were often well below zero. There were many days too when the sky was cloudy, greatly limiting the available light and solar gain inside the structures. I was fearful that the ranunculus and anemones wouldn’t survive these harsh frigid conditions (and that the low tunnels would collapse under the weight of the snow, but they didn’t). I’m here to say, these babies are TOUGH! In fact, I’m expecting a bumper crop this spring.
Both the plants in the hoop house and the low tunnels have been kept under a double layer of Agribon fabric during the coldest stretches of the winter. The fabric is taken off on warmer days so the plants can get the maximum light. Watering and fertilizing with a cocktail of fish emulsion, kelp, and compost tea has been limited to when temperatures were going to be above 25F at night for at least three days (that’s only happened twice all winter!) so growth has been a bit limited by the lack of water and nutrients. Ideally both crops should be watered deeply and fertilized once a week when they’re actively growing. These crops love to soak up water and nutrients. Anemones in particular love a deep drink.
Weed management is a crucial key to a highly productive crop. If it’s warm enough in the tunnels and hoop house for the ranunculus and anemones to grow, it’s warm enough for the weeds. Weeding in the hoop house is not that hard and actually kind of nice on a winter day when it’s warm inside and cold outside.
But weeding the low tunnels is really tricky since you have to kneel on the ground in the snow or mud. We’d struggled to keep up with the weeds until this season, when we’ve started using a new product called FloraFlow, which is black plastic with pre-punched holes that are perfectly spaced and sized for growing ranunculus and anemones. This weed barrier has been superb at suppressing weeds and no doubt key to it looking like one of the best crops to date in the low tunnels. I think the black plastic has also kept the soil warmer through the cold snaps. That’s great in the winter but a problem once it gets hot outside so we’ll be covering the plastic with straw as things heat up.
For growers who have not tried either of these crops yet, I would highly recommend starting out with just anemones. They are able to withstand cold better than ranunculus, and they have a longer bloom window than ranunculus, making it easier to get a profitable number of stems while you fine-tune the mechanisms for keeping them happy in our cold winters. Once you’ve tried your hand at anemones and feel confident, add ranunculus.
Both crops fizzle out when the temperatures get in the 70s. Usually plants are done producing by mid-May. If we’re lucky, we can eek out a couple dozen stems for weddings until the first weekend of June. I really love it when the peonies and ranunculus overlap. Pure designer bliss!
Storing Ranunculus: When And How To Store Ranunculus Bulbs
Glorious ranunculus makes a delicious display in groupings or simply in containers. The tubers are not hardy in zones below USDA zones 8, but you can lift them and save them for the next season. Storing ranunculus tubers is quick and easy but there are a few rules to observe or the tubers will not have enough energy to bloom the next year.
They are also prone to rotting if ranunculus bulb storage is not done properly. Learn how to store ranunculus so you can enjoy their brilliant colors and prolific displays of tissue paper-like blooms.
When Do You Dig Ranunculus Bulbs?
Bulb and tuber storage is not necessary in some zones, but if you have a tender variety it would be a sin not to try and save them for the next year. It is important to save ranunculus bulbs over winter in areas prone to any freezing, as they are extremely sensitive and will not survive much more than a light frost. Fortunately, it is a simple task that you just have to remember to do before that cold weather threatens.
It may seem like a trivial detail, but knowing the answer to the question of, “When do you dig ranunculus bulbs out for winter” is an important piece of trivia. This is because tubers and bulbs are plant storage organs with carbohydrates nestled away for new plants to use for growth before they put out adequate roots.
Any of these organs need to collect solar energy, which they turn into carbohydrates or plant sugars. The only way they can do this is through photosynthesis with their leaves. For this reason, leaving the tubers in the ground until the foliage has faded provides the organ with essential energy for the next season’s growth.
Additional Reasons for Ranunculus Bulb Storage
In addition to the fact that the plants are not winter hardy in the colder zones, storing ranunculus may be necessary in warmer regions. This is due to the presence of digging mammals, which like to nibble on the high energy organs. These would include:
Most areas of the world have at least one pest animal that will dig up and chow down on their prized bulbs. If these types of animals are present in your garden, it is vital to save ranunculus bulbs over winter. It’s much more economical than purchasing new bulbs and tubers the following spring.
How to Store Ranunculus
The most crucial issue is drying and dry storage. Many gardeners have experienced the futility of storing bulbs only to find they succumbed to moisture and rot over the winter.
Dig out the tubers when the foliage is dry and dead. Cut off the leaves and allow the tubers to dry completely for several days, either indoors in a warm low humidity room, or simply out in the sun.
Store the tubers packed in dry moss, such as peat, in a mesh bag. Those mesh onion bags are a great thing to save for storing any bulb or tuber.
After the cold season is over, start the tubers indoors in February and plant out when the soil is warm and workable. In temperate zones, you can install them directly into garden beds by mid-April to May for blooms in June or July.
Prolific and Terrific: Ranunculus
Brilliantly colored flowers are ‘ranunculus’ chief attraction, and they are indeed special. They most often come in multiple layers of delicate, crepe paper–thin petals, looking like an origami masterwork. Ranunculus (R. asiaticus) excel in southern and western gardens, and make terrific container plants everywhere. They also make long-lasting cut flowers. Bulbs are widely available in Fall at retail nurseries in mild-winter climates; in Fall and early spring from mail-order catalogs.
Ranunculus leaves, grass green and vaguely celery-like, grow in a mound 6 to 12 inches across. Flowers on 12- to 18-inch stems emerge in March from fall-planted bulbs, June and July from spring-planted bulbs; they last up to six weeks. On the most common type, the Tecolote strain, flowers are mostly fully double, 3 to 6 inches wide, and available in bicolored picotee, gold, pastel mix, pink, red, rose, salmon, sunset orange, white, and yellow. The less common Bloomingdale strain is shorter, to 10 inches, with pale orange, pink, red, yellow, and white double flowers.
Where and How Ranunculus Grow Best
Broadly speaking, ranunculus are frost-hardy cool-season perennials. They perform best where winters are relatively mild and springs are long and cool. The roots tolerate soil temperatures to 10°F, while growing plants can handle temperatures below 20°F for several hours.
Ranunculus are most popular in the mild-winter regions of the South and West, in states such as California, Nevada, Arizona, New Mexico, Texas, and Louisiana (USDA Hardiness Zones 8 through 11), where they grow best. Planted there in October or November, they flower in March.
Bulb size predicts the number of flowers. Each jumbo bulb will produce some 35 cuttable flowers, compared to a fifth as many from a number three bulb. Number ones will make about 20 flowers, number twos a dozen or more. Stick to jumbos for containers and most smaller plantings. Smaller number twos or even threes serve well for mass plantings.
At retail nurseries this fall, you can expect to pay about 50 cents for each jumbo bulb, 25 cents for number twos. Increasingly, nurseries also offer ranunculus in fall or spring as bedding plants in 4-inch pots. While the cost per bulb in pots is greater, this is a good option if you need only a few plants for a container.
Gardeners in zone 7 and north (Richmond and Reno to Minneapolis) can also grow ranunculus, but on a different schedule. In these regions, plant in early spring a week or two before the typical last frost.
Or, plant them in pots indoors in February for transplanting later. Place pots in a south- or west-facing window or under grow lights. Temperatures around 55°F are ideal. In early spring, gradually acclimate plants to outdoors by putting them out for more time each day (bring them in at night). Plant outdoors by mid-April in zones 6 and 7 (mid-May in zones 4 and 5). Spring-planted ranunculus will bloom in June or July.
Dry and hard when you buy them, tubers soften and plump up after absorbing moisture. You might be advised elsewhere to soak tubers before planting. It’s not necessary, and if you happen to leave them in water too long, they’ll turn to mush.
Choose a location in full sun and be sure the soil is well drained. The one environment that ranunculus do not tolerate is warm and wet. The cool soil of fall and early spring offers some protection from rotting, but soil that is never soggy gives extra insurance. Plant the tuber’s claw pointed end down and 1 to 2 inches deep, less in clay soil. Space jumbos 8 to 12 inches apart (at least one tuber per square foot), number three tubers about 4 inches apart (two or three per square foot).
Ranunculus adapt easily to container life, but they do produce a large root system. A 10-inch pot can fit one or two jumbos or three number twos.
Whether tubers are in the garden or in pots, water thoroughly after planting, and apply a mulch of your choice: bark, coco hulls, and straw all work well. As long as soil retains some moisture, don’t water again until you see sprouts, usually within 15 to 20 days.
Here are two ranunculus color schemes that have proven popular. Interplant pink ranunculus with salmon Iceland poppy and red-purple pansies, and accent with a few yellow and pink English primroses. Another favorite scheme combines salmon ranunculus with blue Chinese forget-me-not.
Ranunculus from seed. If you can locate seed for sale or through a swap, they’re definitely worth the effort. Sow in a lightweight, peat-based seed-starting mix in late winter, maintain soil temperature at 50°F, and allow 20 to 30 days for germination. Sow thickly, because the number of seeds that actually grow is low. After germination, maintain seedlings indoors at about 55°F until outdoor planting time. Plants will flower by June.
As cut flowers. Beyond their intrinsic beauty, ranunculus flowers have another virtue: they last indoors about 7 days after cutting. And at about a penny-and-a-half per flower, they are very inexpensive. Cut when flowers first show color, in the early morning after they have had the night to recharge themselves with moisture. For an additional day or two of vase life, add any floral preservative to the water.
After the flowers fade. For some lucky gardeners with perfectly drained, cool soil, the tubers can stay in place and be treated like any perennial that comes back year after year. But this is rare. Most gardeners treat ranunculus as annuals, disposing of them after bloom. You could pull and compost plants, or leave them in place to fade away. In most gardens, the tubers will rot in moist summer soils. More ambitious gardeners can save the tubers for replanting next year. Let blooms fade and plants dry out. Lift tubers, cut off tops, and store in a dry, cool place for planting next year.
Michael MacCaskey is a former editorial director at National Gardening.
This very large genus comprises about 250 species of widely differing habit and appearance, but the three listed here are the ones most commonly grown in gardens. Not browsed by deer.
How to Grow Ranunculus
Tuberous roots are hardy to 10F. In the Coastal and Tropical South (USDA 9-11), plant in fall for bloom in winter, early spring; treat plants as annuals there. Beyond hardiness range, plant in spring as soon as ground is workable; or start roots indoors four to six weeks before the usual last-frost date. Nurseries sell tuberous roots of various sizes; all produce equally large blossoms, but bigger roots yield a greater number of flowers.
Grow in full sun, in organically enriched, very well-drained soil (if necessary, plant in raised beds). Set roots with prongs down, 2 inches deep (1 inches deep in heavier soils) and 68 inches apart. Water thoroughly, then withhold water until leaves emerge. Birds are fond of ranunculus shoots, so protect sprouting plants with netting or wire. Or start plants in pots or flats, then set them in the garden when they’re 46 inches talltoo mature to appeal to birds. (You can also start with nursery-grown seedlings.) Remove faded flowers to encourage more bloom.
When flowering tapers off and leaves start to yellow, stop watering the plants and allow the foliage to die back. Where tuberous roots are hardy in the ground, they can be left undisturbedas long as soil can be kept dry during summer. Some gardeners dig plants when foliage turns yellow; cut off the tops; let roots dry for a week or two; and store them in a cool, dry place until planting time. But because roots don’t store that well, most people find it simpler to discard the plants and set out new roots when the time comes.
- Zones LS, CS, TS; USDA 8-11 (see below).
- Native to Asia Minor.
- Tuberous-rooted plant to 12 feet tall and wide, with fresh green, almost fernlike leaves.
- Blooms profusely in spring, when each flowering stalk bears one to four 3- to 5 inches-wide, semidouble to fully double blossoms that some say resemble small peony blooms.
- Flowers come in white, cream, and many shades of yellow, orange, red, and pink.
- Popular Tecolote Giant strain is available in single colors, mixed colors, and picotees.
- Bloomingdale strain offers the same range of colors on dwarf plants 810 inches high.
- All types are good in the ground or in pots.
- Zones US, MS, LS, CS; USDA 6-9.
- From Europe and Eastern Asia.
- Aggressive, weedy perennial spreading by bulblets on stems and underground tubers.
- Forms a dense mat of heart-shaped, 1- to 2 inches-wide, shiny, dark green leaves, mounding to 34 inches tall.
- Bright yellow, buttercup-like flowers rise above the foliage in spring.
- Dies back in late summer.
- Has become a rampant weed in some areas.
- Full sun or part shade.
- Less aggressive selections include ‘Brazen Hussy’, with purple-black leaves; ‘Collarette’, with heart-shaped leaves marked with silver; and ‘Randall’s White’, with cream-yellow flowers and leaves marked with silver.
ranunculus repens pleniflorus
- Zones US, MS, LS, CS; USDA 6-9.
- From Eurasia; naturalized in North America.
- Vigorous plant with thick, fibrous roots and runners that root at the joints.
- Forms a lush, glossy, green mat to 1 feet high, 6 feet wide; leaves are roundish, deeply cut into three tooth-edged, 2 inches-long leaflets.
- Fully double, 1 inches., button-shaped, bright yellow flowers are held above foliage on 1- to 2 feet stems in spring.
- Can be invasive in constantly moist soil.
- Attractive deciduous ground cover for full sun to deep shade.
- Basic species is single flowered and just as aggressive as Ranunculus r.