There are SO MANY different kinds of ranunculus to choose from! It's hard to know why the price varies so much and what's up with all the different kinds. I'm going to share my experience with the varieties I am familiar with thus far. Please seek out the largest corms you are able to find when shopping for ranunculus. 5/7 (I assume that's the diameter of the corm in centimeters) is the a good size. TLDL: You get what you pay for, and size definitely matters!
First, I have to admit that my favorite line of ranunculus are the Italian ranunculus sourced from Onings America. In my warm climate where we grow in winter (that sometimes has weeks of 80 plus degrees) these perform beautifully. They are reliable, productive, have nice tall stems and come in a dizzying array of colors of petal shapes. Elegance is their more affordable line and is grown the old fashioned way. Their cloned lines are called Success and Pon pon (which I assume is Italian for pompom).
The Cloni (sometimes called Clooney by florists) line is produced by tissue culture (cloning) and has either the Success (for the more common petal forms that resembles a rose) or Ponpon for the ruffly petals that sometimes are mixed with green and make a pompom looking ball. They are quite expensive and make larger flowers. They are distinct and fantastic! Fiesta is their more affordable version of Ponpon but only comes in a few colors or mixes.
These are a more recent addition and are more wildflower looking. They don't have the ruffly petal-filled flowers that the more common ranunculus have. They are bigger plants with tall stems and multiple flowers on a stem. They are wonderful mixed in a vase with regular ranunculus.
These are more affordable than the Italian varieties and are fairly heat tolerant - important for our climate. The flowers aren't as large as the Italians but they come in all the colors people want so these are a great way to try out ranunculus and figure out your techniques without risking so much money. I don't have photos that I feel confident are Amandine varieties but if you google some "Amandine ranunculus" you'll find lots of beautiful colors. Chamallow is a blush pink, Juliet, a bright pink, and Purple Jean a soft lavender.
I'm still not sure how I feel about these. The photos are incredible but in my trials last year (I tried 10 of Maillane or Maritime (can't recall which) and only 2 of them grew. In the facebook group for flower farmers I read that the company that produces these harvests their corms earlier than other companies and that might be why they aren't as reliable. That's definitely a con HOWEVER they have colors that you don't see from other lines. I'm giving it another try this year with a lot more varieties and will report back on how they did. So far in the pre-sprout stage I'm not very impressed. Maybe they are just slow? I'll keep my fingers crossed because the corms are quite expensive.
These are super affordable! That's a great thing if you just want some lovely flowers to look at in your garden. If you want sturdy stems to harvest you might want to pass on these. They can be fine but they aren't bred for the flower farming market so the focus isn't on making plants with sturdy stems. They are a GREAT line to practice with until you have your growing technique solid.
Why to grow ranunculus
Because they are so incredibly beautiful!