By Josh Volk


This trip and article are a follow-up to a trip that I took to Italy in 2014, also with Lane Selman and a few others. After that trip, I wrote an article called “How to grow heading chicories,” in the November 2016 GFM. It has details on growing many of the more common radicchios and other chicories, but it didn’t address forcing. It’s worth checking out in the archives as a companion to this article.


In January of this year I was fortunate to be one of about 20 growers, chefs and journalists to join Lane Selman of the Culinary Breeding Network on a trip to the northeast of Italy where there is a long tradition of radicchio and forcing chicories. Look at a map of that area and you’ll see town names like Chioggia, Treviso, Castelfranco, Verona, Lusia and Gorizia – all towns that are associated with one or more types of radicchio.

We were lucky to have a young Italian grower, Myrtha, as our fixer and she arranged three very full days of farm and seed company tours for us, many chicory influenced meals, and capped it all off by organizing a festival of winter growing at her home farm, which happens to be an amazing biodynamic winery, Foradori, in the Dolomites.


Isontina type radicchio packed for sale. These were grown in the Friuli-Venezia Giulia region of Italy and forced in water.


That festival attracted small growers from even more regions of Italy, and many brought displays of the chicories and other winter crops they grow. The trip was completely overwhelming, exhausting and inspiring all at the same time. And, I learned a lot about how growers in this region force chicories (mostly radicchio), as well as how they grow a number of other winter crops.

“To force” means to encourage plants to sprout new growth before they naturally would in the field. This is often coupled with blanching, which is to exclude light in order to reduce the chlorophyll in the leaves, making them paler, bringing out background colors, and making the leaves more tender and milder. My basic takeaway from visiting and talking to growers from multiple farms across several regions in Italy was that there is no standard way to force chicories, and that different farms have their own ideas of how it is best done.

This is usually based on the resources they have on hand and convenience as much as any kind of tradition. The best-known forced chicory in the US is Belgian endive, not usually considered a radicchio and not from northern Italy but grown using a similar process and from the same species, Cichorium intybus, rather than C. endivia as you might expect given its name.


Tardivo with leaves cleaned off but roots intact. Before these are packed for sale they will have the roots peeled.


Treviso tardivo

According to Andrea Giubilato – an organic farmer in the Veneto region considered by many we met to be the King of radicchio - this is the original radicchio and it appears in at least one painting hanging in the Louvre that dates back to the 16th century. Tardivo is the Italian word for “late” (think “tardy”). You will see the word tardivo applied to different radicchio types but when it is used by itself it generally refers to Treviso tardivo. Giubilato harvests his tardivo from the end of December to mid-February.

The 45th parallel bisects the area, putting it in the same latitude range and day lengths as northern Oregon, the upper Midwest and northern New England. The winter weather in this part of Italy is typically slightly below freezing for weeks at a time, but the cold alternates with temperatures a bit above freezing and occasional rain making the climate perhaps most similar to the Pacific Northwest of all of those places. In the late summer and fall the weather is a bit warmer with more humidity than the Pacific Northwest, perhaps more similar to the upper Midwest or Northeast.

While we were there the temperatures were actually fairly mild and skies were sunny to overcast, in the upper 30s and 40s Fahrenheit with some freezing at night in some of the higher towns. The soils in Treviso are typically heavy and there are many springs that provide water in the winter. The relatively warmer spring water is commonly used as the forcing medium in that area.


Forcing Isontina (foreground) and Tardiva (background) in troughs of slow moving water inside unheated greenhouses.


The most common method we saw for forcing tardivo was to dig up the plants with a few inches of roots intact but most of the soil knocked off, strip a few of the damaged outer leaves, and then pack them tightly into plastic bulb crates and either start forcing them immediately or, if the plants were dry, to put them into cold storage for forcing later.

If the plants were too tall for the grower’s likes, the leaves were cut flat with a hedge trimmer to encourage a shorter finished product – the idea being that the new leaves shooting up will start to curl over when they see more light as they begin to emerge out of the mass of older leaves, keeping the resulting head from getting too long.

For forcing, many farms built low troughs about five inches deep in the ground inside unheated hoop houses. They sides and ends of the troughs were made from wood or cinder blocks and then lined with heavy black plastic. Usually there was a grid of wood and rebar, or something similar, at the bottom to hold the crates off of the bottom, and at the tail end there would be a slightly lower section for water to drain out of, typically into a ditch.

At the head end a hose or pipe would add a slow flow of water to the trough, just enough to keep the roots submerged. One grower I talked to didn’t have the ability to leave water running so he just changed the water every few days.


This is the forcing setup for Tardivo at a small farm in the Veneto region. Water is slowly and continuously fed into the troughs and exits through pipes plumbed into the top of the far sides. All photos courtesy of the author.


After 15 to 25 days, depending on the temperature, the tardivo was ready to be cleaned. Outer leaves were stripped until only pure white ribs with deep red edges remained. Roots were trimmed to about 1” and also peeled with four or five strokes of the knife. The only blanching came from the outer leaves that were tightly packed in the crate.

To grow the plants to the forcing stage all of the farms we talked to were planting seedlings in mid-August. Some side dressed fertilizer after planting, and others relied on the existing fertility in the soil. Plant spacing was typically about 12-16” between plants and 16-20” between rows.


This is a field of Verona waiting to be harvested in January. This planting is harvested from one end of the field to the other over the course of four to six weeks.


Gorizia or Isontina

We didn’t actually go to Gorizia, but they are well known for a forcing type which creates a rose-like effect which is stunning. Outside of Gorizia these are usually called Isontina and we commonly saw these red varieties alongside a yellow version called Canarino, and the variegated Castelfranco (or possibly sometimes Lusia which are also variegated – both being called variegato but having slightly different colors, leaf edges and tendencies to make either a looser or tighter head).

These were mostly forced in the same way as the tardivo, but likely were grown on slightly tighter spacing as they are typically smaller plants. The other difference was that when they were given their final cleaning some care was taken to open up the heads a bit to give them their rose-like appearance and they were also dunked in cold water to make the leaves curl out like rose petals.

One grower we visited in Udine was not using water for forcing Isontina, but instead was using a mix of damp sand and cow manure. She was replanting the roots at a tight spacing in the sand mix in stalls in the back corner of an old barn and then covering the stalls with black plastic. To avoid ruining entire batches of plants with rot she checked daily to make sure no rot had started as it apparently will spread very quickly.


This is the basic frame of a forcing structure at Entroterra. The farmer covers the ground with several layers of plastic to create a low pond, and then covers the hoops with black plastic to keep light out. You can see a Youtube video of their process on the Entroterra channel.



I saw Castelfranco being grown multiple ways and one of the most fascinating stories I heard about this variety of radicchio is that it is a cross between tardivo and escarole – and the progenitor of Chioggia and Lusia types. As I mentioned above, on some farms it was being forced and grown small and then opened like an Isontina.

I also saw it being forced and blanched at a larger size, in the field. Plants were pulled up with their roots and then basically piled (mostly standing up) under low hoops with a layer of row cover and a layer of black plastic (presumably the row cover kept condensation from dripping but I didn’t actually ask).

After three weeks under the cover the outer leaves were stripped (looking a bit slimy), and the inner heads, which were beautifully blanched, were packed into crates. This forcing and blanching method seemed to mimic stories I heard on my last trip to this region about Castelfranco being harvested before especially hard freezes and stored in straw in barn stalls for later use.


Pacific Northwest farmers Jason Salvo and Dan Sullivan checking out the impressive display of forced chicories from Rosato Farm in the Veneto region of Italy. This display contains Tardiva, two types of Isontina, Canarino, Castlefranco, and the farmer’s own cross of Isontina and Castelfranco


A few non-forcing types

In addition to the forcing types we saw quite a bit of Radicchio col poc (or Lidric col poc), red and green Grumulo and Castelfranco with the root on. In the Friuli dialect poc means root and this was just one example of regional dialect we heard used in relation to radicchio. I was told this is grown by broadcasting the seed in mid-July and with the goal of 1 plant every 1 to 2 inches.

The plants are then cut back to four or five inches high once or twice before the first frosts kill the outer leaves. Once there have been at least three frosts the inner rosettes will be sweet and are harvested roots on and trimmed and peeled to a little point. These can continue to be harvested until early March with the different varieties each having seasons when they are best, but all being very cold hardy and harvested through most of the winter.

Another chicory that was new to me was Cicoriella zuccherina di Trieste. As the name suggests this one is from Trieste and if you recognize the Italian it’s a sweet little chicory. Again, this one is broadcast, but this time it is cut like a baby salad green. It can be cut multiple times but it gets more bitter with subsequent cuttings.


This is Castelfranco being cleaned after forcing in a pile covered with low hoops, floating row cover and black plastic. In the foreground is Verona waiting to be harvested.


Seed selection

Another revelation for me, something that should have been obvious is that just like every other crop, radicchio varieties are continuing to evolve. Treviso tardivo may look similar to a crop from 500 years ago, but many of the types we see today have been around for less than 100 years, and some for only a few decades or less. Even the ones like Castelfranco which are quite old are evolving.

We tasted a selection on one farm that was a very old style, handed down from farmer to farmer and never in the commercial seed trade. On first glance the farm selection and the commercial variety were the same crop but the flavor and texture were very different and the color was also subtly changed. It was clear that the commercial variety was bred for size, and probably to self-blanch. The farmer-selected seed had much better flavor and texture and a deeper yellow that likely only came out with actual blanching.

Many of the farmers we met with had at least one variety that they were saving their own seed for, selecting for the characteristics they wanted. A lot of the radicchio in Italy is a commodity crop, with farmers selling pallets of cases for ridiculously low prices. For the most part the growers we met with were sticking to more specialty types where they could still get a higher price for their quality. In some of those cases part of what was unique about their radicchio was the work they had put into selecting and improving varieties.


A field of Tardivo waiting to be harvested.


Varieties for North America

I don’t know all of the sources and I think some of the biggest specialty growers in North America are working directly with companies in Italy. I’m not sure what they will have for the coming season but Osborne here in the NW has previously carried T and T Seeds ( and are starting to work with Levantia (both Italian seed companies). Their varieties are solid commercial varieties, definitely the best I’ve worked with.

Franchi Seeds from Seeds from Italy have previously been the best varieties I’ve worked with, and they have the most complete line I’ve seen here. Gourmet International I’ve gotten from in the past and I would not recommend those. Uprising, Adaptive and Wild Garden Seeds all have limited selections of chicories, but what they do have has been good for me. I haven’t grown from other companies for a while, and I’m not familiar with what regional suppliers in other parts of the country are carrying.


Tardivo for sale in a farmers market in January in Bologna, Italy.


Adding to the winter mix

There are a few reasons that I love growing radicchio on my farm. First of all, it’s delicious. I tend to only grow it for fall and winter when it’s at its sweetest and least bitter. When it’s grown and harvested properly it’s actually not very bitter at all, although the argument against any bitterness at all falls apart when you realize that coffee and chocolate are two of the most loved tastes in the world and they both have bitter elements. Over time I’ve actually come to love the bitter element in chicories.

For me chicories, including endives, escaroles, Catalogna, and radicchio, are all crops I grow to extend the salad season after it gets too cold for lettuce. Unlike lettuce, chicories also have more cooked uses in addition to being great raw in salad. With a little luck with the weather and good planning I can make the chicory season last from October into March, right when the first spring lettuces and baby brassica greens are starting to reemerge.

Besides providing diversity in my winter diet they also provide diversity in the field and a way for me to displace some of the brassicas, which I usually have too many of for healthy crop rotations. Part of the background for the trip to Italy is a project that Lane Selman and the Culinary Breeding Network is doing to promote winter vegetables, vegetables that are best during the winter and ones that require minimal season extension and storage infrastructure. In addition to sharing what we learned about production methods, the goal of the project is also to encourage chefs and home cooks to use more winter vegetables and increase the demand for them from local growers.


Castlefranco and Lusia types aren’t always forced but it is common to find them “opened” during packing to expose the self blanched centers. Dunking them in warm water (65° F) helps make the process easier.


Josh Volk farms in Portland, Oregon, and does consulting and education under the name Slow Hand Farm. He is the author of the book Compact Farms: 15 Proven Plans for Market Farms on 5 Acres or Less, available from Growing for Market. He can be found at