So, on the list for this year's new things to explore-forcing radicchio. I got a better idea about how to do this after e-mailing the owner of Seeds from Italy and asking him about how to do this. I also saw a great youtube video produced by an Italian company that grows the Treviso Tardivo variety of radicchio. Here is what Seeds from Italy sent me:
Growing fancy radicchio the way they do in Italy. This is based completely on some email conversations I had this past December with one of my favorite farmers. Tim Wilcox grows out in the Connecticut River Valley in Massachusetts (this is the only place in the state where you can dig down more than six inches and not find very big rocks). Tim has spent a lot of time in Italy and, as am I, he is passionate about things Italian. We were having an email exchange about something and he sent along this report along with some stunning photographs of the Treviso radicchio he grew in good old Massachusetts. This is definitely the way to grow it, at least in areas with more severe winters. I put the description below together from two separate emails.
In brief, the radicchio was grown like this:
June 15 seeds sown in flats. July 15 transplanted to the field spaced 9-12"x18" for the rows. (I direct sow in July). Direct seeding would probably yield a higher average final weight, but there's the added work of thinning and weeding. Plants grow well with minimal fertility. Plants are allowed to grow until after a hard frost, with no special treatment. Then they are dug up root and all, the dead outer leaves pared back, and formed into bunches of 15 plants. At this point in time (60-75 days from setting out transplants) the plant has not yet formed much of a head at all in the field. They can be dug any time until the ground freezes. The roots are trimmed level, leaving about 4-6" at least. Then they are set in a bucket or washtub of water to the level of the root in utter darkness for 2 weeks at 55° or ideally 3 weeks at 45°. (I did mine in the garage for at least 3 weeks) They do not cut the head, but just remove the outermost leaves and bunch the plants tightly together. This forces them to grow very compactly, and the outer leaves shield the hearts from both light and rot. In Treviso they use these huge basins with running water, but it works well on a small scale like this[ using a big bucket filled with water]. When ready they are trimmed of all outer rot and washed well. The unforced roots can be stored in a cold root cellar or refrigerator until needed. They have tardivo as late as April in Italy.
Here are pics of my first results. I tried two varieties of Treviso radicchio. The first batch that I picked up was the Treviso Tardivo and they were a bit smaller because I picked from my smaller (in size) crop where I sowed them. The transplants, of course, are bigger because they have more space to grow. The second batch are the plain Treviso type. A few of the larger ones are picked from my transplants and some are also picked from the sowing bed. The forcing didn't make them as red as I was hoping for, but they are crisp and tasty. Good all the way to the root. I am also adding some pics of the endive and other radicchio that I blanched.
|Smaller and younger Treviso Tardiva pulled and ready to force|
|A close up of the roots. You will see that these are a good deal smaller than the next batch|
|Growing in the dark for almost 2 weeks|
|The group of the first batch after about 2 weeks and cleaning off some dead outer leaves|
|End result of first batch after over 3 weeks (again these are smaller because they started out small)|
|Batch #2 Treviso|
|Some of these larger ones were already forming a decent heart|
|Blanched Pan Di Zucchero|