Green Cauliflower (Vitaverde) is as easy to grow as any cauliflower. Have not tried the Romanesco types. Cauliflower in general is much more temperature sensitive than broccoli. Too high it won't head and the heads will freeze and brown below 25 degrees F. I grow early DTM varieties in Spring, longer DTM varieties in Fall. But I am in middle Georgia. With cooler summer temps, you could grow thru the summer for harvest in September. My harvest is December.

I've successfully grown green macerata & purple of sicily cauliflower for a few years (Botanical Gardens sells a pack of seeds called "Chef's Choice Gourmet Cauliflower" which was fun to try and introduced me to these 2 varieties). The Romanesco was a little more difficult-- I've tried for several years and just finally timed it right this year and harvested my first Romanesco on Christmas Eve! I started all my brassica seeds early July and have had a steady harvest of different varieties since October--Romanesco is the last one to mature.

Another fun one to try is the overwintering type, which I also start in July. These won't be ready here in the Pacific NW until the spring, but I have purple cauliflower and a purple sprouting broccoli. But like others have mentioned it all depends on where you're located, and then it might take some trial & error...

I'll think i'll try seeds for 'Green Macerata' and 'Orbit' F1 hybrid Romanesco.

Think I grew 'Vitaverde' last year, I bought unnamed "Broccoflower" seedlings at a nursery. The big plants grew very well in early summer heat, heads were shaped just like common cauliflower except intense chartreuse but I didn't like the taste, maybe it was the late June maturity in Ohio.

In November 2013 I picked this common generic "white" cauliflower that I planted late August, and it grew cool like this. Anybody know why? The late Autumn maturity?

I grew the romanesco broccoli one year by accident. They tasted very creamy!

I planted some this year in a new raised bed, but we ended up having not enough sun! Hoping they'll get a head in the spring when the sun hits them better! The plants look great, just no heads!

Romanesco Broc and purple cauliflower are both producing! YAY!