Forcing Belgian Endive and Treviso Radicchio in The Upper Midwest

Progress report for FNC20-1251

Project Type: Farmer/Rancher
Funds awarded in 2020: $4,945.00
Projected End Date: 12/31/2022
Grant Recipient: Waxwing Farm
Region: North Central
State: Minnesota
Project Coordinator:
Peter Skold
Waxwing Farm
Expand All

Project Information

Description of operation:

Waxwing Farm is a diverse, family farm devoted to raising fresh to market produce, pastured pork and pastured poultry in the most sustainable way we can. We are not certified organic, but we grow as if we were. That means we do not use any products or practices that are not approved by the National Organic Program (NOP). We have not pursued organic certification because we direct market all of our farm products. We know each of our customers personally and we feel that we can adequately convey our growing practices to them through that relationship.

Neither I, nor my wife, Anna Racer, come from farming backgrounds. However, after working on other farms for three years, we started Waxwing Farm on a rented acre in Stockholm, Wisconsin in 2011. In that year we grew vegetables for a 20 member CSA program, to sell at the Fulton Farmers market in Minneapolis, and for one local restaurant. In 2012, we purchased an old farmhouse and 40 acres in Webster, Minnesota and have been here ever since. In the past seven years, our CSA program has grown to supply 160 families (100 full share equivalents), six restaurants, two caterers, two college dining halls (St. Olaf College and Carleton College), one food co-op and one small town grocery store. We currently market our pasture-raised pork and eggs to our CSA customers exclusively. We used to sell at farmers markets but stopped in 2018 to focus on our CSA and other accounts exclusively.

Currently, we grow 6 acres of vegetables to supply our various markets. We utilize a greenhouse to grow all of our own transplants as well as two unheated hoop houses for early and late season leafy greens sales. 60% of our sales come from CSA shares with our restaurant and food service accounts making up the bulk of the remainder. We grow a wide variety of vegetables, herbs and fruit to keep our CSA and chef customers interested. Tomatoes, Brussels sprouts, head lettuce, leafy greens, culinary herbs, and edible flowers currently represent the most significant portion of our sales outside of CSA shares.

Anna and I both work full-time on the farm. Additionally, we hire 3-5 part time seasonal workers during the growing season. Our long term goal is to expand sales enough to justify hiring a full-time, year-round employee. Expanding winter sales is a critical part of achieving that goal.


Season extension is an important practice on vegetable farms in Minnesota. By lengthening the growing season, farmers can extend their sales into winter when cash flow would otherwise cease. High tunnels and root crops are the preferred method, but these options have limitations. Leafy greens from unheated hoop houses are in high demand, but they do not regrow during the dead of winter, thereby limiting harvests. Conversely, root crops are relatively easy to grow and store but are low margin crops necessitating high volume customers. For smaller farms selling through lower volume outlets like CSAs, restaurants, and farmers markets, this poses a problem.

Forced radicchio and endive could solve this problem. Radicchio and endive are high-value specialty crops that require being dug from the field and forced indoors, without sunlight. They are harvested at the end of the growing season and forced in the winter months. They could offer a high-value, high-margin crop to make lower volume winter sales more lucrative.

This project will evaluate the feasibility of radicchio and endive as season extension crops in Minnesota. Results will be shared through our farm's social media outlets, our local Sustainable Farming Association chapter's annual meeting, and written publications.

Project Objectives:
  1. Evaluate the feasibility of growing both Treviso radicchio and Belgian endive in Minnesota.
  2. Compare different forcing techniques for both crops.
  3. Determine profitability of growing Belgian endive and radicchio.
  4. Share results with other MN vegetable farmers through social media, local Sustainable Farming Association (SFA) annual meeting, and University of Minnesota extension newsletter.


Materials and methods:

The goal of this project is to increase off-season sales while keeping cost down and utilizing idle infrastructure as much as possible. Crops will be planted according to existing equipment limitations. Forcing will take place in an unused walk-in cooler, utilizing the simplest vessels possible.

We will source as many different varieties of each crop as possible for comparison sake. Easily available varieties include 'totem' and 'macun' for endive and Treviso 4 Tardivo for Radicchio. We will source additional varieties as time allows.

Our mechanical transplanter can plant two rows spaced 24" apart with 9" spacing in the row, which works well for head lettuce and early radicchio varieties. Our fields are laid out in 220'x50' parcels. We have space in our crop plan to plant one 220' bed of Treviso radicchio and two of endive, with an expected yield of 500 and 1000 plants respectively. Given our existing market outlets, we feel that this is an amount of forced heads we can reasonably expect to sell in the first year. 

We will require an undercutter bar to loosen the plants from the soil at harvest. Forking by hand would be cost and time prohibitive. 

Radicchio will be harvested into crates for forcing in a temperature controlled water bath, which is the traditional method in Italy. We will construct the water bath using tanks and a simple recirculation pump and aquarium heater. Plants will be forced directly in their harvest crates.

Endive can be forced in a soilless medium of either peat moss or sand, depending on what is most readily available. We will source or build containers that comfortably fit 8" roots, tightly packed. These containers will be stacked in the forcing chamber using existing shelving options. We will try to source containers that can be used for forcing both crops.

Participation Summary
2 Farmers participating in research

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

Due to complications related to the COVID-19 pandemic as well as production related issues, no outreach and education activities have taken place to date. 

Learning Outcomes

1 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Lessons Learned:

2020 was a year with steep learning curves. Due to disruptions related to the COVID-19 pandemic, this project was significantly impacted. However, we learned a lot of great lessons related to the production of forcing radicchios and Belgian endive. We overcame some barriers but faced many new ones because of the pandemic. The project so far represents a proof of concept that still needs more work to be fully realized. 

First, the positive.

More than anything, this year proved that it was possible to successfully grow and force both radicchio and Belgian endive in Minnesota. We learned a lot about growing these crops that is not immediately evident from the available literature from seed companies regarding how to grow and force these chicories. We learned that direct seeding these crops is much more preferable than transplanting for a few reasons. First, chicories are temperature sensitive and they struggle to germinate in a hot greenhouse in the middle of summer (late June). One open pollinated variety, Witloof from Seeds of Italy (additional seed that we purchased but wasn't included in the original grant), completely failed to germinate twice in the greenhouse due to excessive temperatures. Second, direct seeded plants grow straighter roots that are much easier to handle both during harvest and in the forcing chamber. Transplanted plants produce gnarled roots that are much more difficult to harvest, clean, and replant for forcing. Furthermore, some of our chef partners have indicated that they might be interested in using the roots in the kitchen where straighter, more uniform roots are greatly preferred. This could be an additional revenue stream from this crop which would add to the overall financial viability of the project. All of these factors point to favoring direct seeding over transplanting. 

An unused walk-in cooler is a perfect environment for forcing these crops. Both the radicchio and endive were able to grow properly with minimal supervision inside the cooler. Space did become an issue as we learned that forcing in successions is critical in order to have finished product over a long period of time. We discovered that there is a point of diminishing returns in the forcing chamber where plant growth is sacrificed to spread of rot. For radicchio, this happened after three weeks. For endive it was closer to 7 weeks. If we continue growing these crops, a size upgrade to our secondary cooler will be necessary. 

Furthermore, there is an additional opportunity for further exploration in the production of forced radicchio. Much of the currently available information on forcing radicchio is traditional/culturally significant in nature. The only way to do it is the way it's been done in northern Italy. Belgian endive, on the other hand, has a broader appeal and longer history of large-scale production. It would be interesting to explore what production practices that work for endive could be applied to radicchio. For example, can the radicchio roots be vernalized and stored for staggered forcing throughout the winter like endive? Do they need to be forced right after being dug from the field? Is running water necessary in the forcing set up? Incorporating some of these practices into the production of forced radicchio could make it a much more viable crop that could be available for a longer window of time. We did plant a late round of transplants into one of our hoop houses that we were able to dig up and force for a second round of forcing. However, they were small and the yield was disappointing. Also, hoop house space is highly valuable, and planting more radicchio to be forced in the manner of endive would be more cost effective while freeing up that hoop house space for other things.

On to the challenges.

As already noted, we discovered that it was very difficult to germinate chicories (radicchio and endive) in our greenhouse in the peak of summer. Even with shade cloth and airflow, temperatures were too hot for satisfactory germination. The Witloof variety did not germinate at all. As such, we transplanted out significantly less of both crops than we had hoped - 3/4 of a bed of radicchio and 1 bed of endive. Direct seeding with regular watering for germination would have produced much more satisfactory results.

We also had issues due to errors made during the harvest of the endive roots. Based on the research we did, we had not read about how critical the amount of greens left on endive roots is to forced chicon production. It turns out that an inch or two of greens must be left on the root in order to produce a marketable chicon. As such, most of the endive greens were cut too close to the root at harvest. This resulted in roots that grew many tiny shoots rather than one properly sized chicon. Nowhere in the available growing information was it made clear how critical this point is to growing marketable endive. Our yields were again severely reduced due to this fact. 

Finally, and most notably, the COVID-19 pandemic and the winter spike in cases caused many of our restaurants to be closed at the optimal time for marketing these products. Restaurants that were open for take-out service were focused on limiting their costs which meant that the market for specialty items like forced radicchio and endive was minimal at best. Thankfully, this meant that our errors on the production side did not impact our relationship with these restaurants or reduce their interest in using these products in the future. Based on conversations with our partner chefs, they continue to be excited about the opportunity to buy these products and optimistic about the demand for them in their restaurants next winter. As a result, we will be requesting an extension of this project so that we can have another growing season to address the production issues we identified and test the market for these specialty products.

2021 Update:

2021 was a year in which we were able to put some of the lessons learned regarding growing and forcing radicchio and endive into practice. We were able to greatly improve our production systems as well as successfully market all of the radicchio we grew and forced. The Belgian endive is still growing in the forcing chamber, but interest from our restaurant partners is strong and we anticipate strong sales. All in all, the 2021 growing season showed us that forcing radicchios and Belgian endive are viable crops to grow in the upper Midwest.

Despite the fact that much of Minnesota was under drought conditions for most of the 2021 growing season, both of these chicory crops (forcing radicchio and Belgian endive) performed well for us. This year we performed a trial and transplanted 1 bed of endive while direct seeding 2. We only transplanted the tardivo forcing radicchio due to seed supply issues. As expected, working with the roots from the direct seeded was greatly preferable to those from the transplanted bed. They germinated well, were easier to dig in the fall, brought less dirt into the pack shed, stored more compactly, and they were easier to load into crates for forcing. The transplanted beds were marginally easier to cultivate and weed, but this fact is greatly offset by all the other benefits of direct seeding. In the future, we will direct seed all forcing chicories on our farm.

This year, prior to forcing, we took the time to peel off most of the outer leaves of the tardivo radicchios. This significantly reduced the amount of decaying plant matter in the forcing chamber. This meant that forced radicchios did not begin to degrade after three weeks, making for improved growth, yield and a longer harvest window. Furthermore, it made harvest of the finished radicchio quicker, cleaner and more enjoyable. This is a practice worth incorporating for future years. Furthermore, we did experiment with harvesting radicchio roots in a similar manner to endive roots - i.e. cutting all of the greens off within 1-2" of the root crown. These roots grew marketable heads that were more or less indistinguishable from those grown the traditional way. We will force another round that has been in storage for 10 weeks to see how they perform. This is promising information in that it indicates forcing radicchios can be handled in the same way as Belgian endive, thereby increasing the harvest window for this crop.

Occasionally, the pump that circulated water through the troughs in the forcing chamber lost its prime and water stopped circulating. We did not notice any change in the performance of the growing plants which suggests that a water circulation system is not strictly necessary. However, stagnant water promotes microbial growth which could negatively impact growth over the long-term as well as be a food safety hazard. If a grower did not have a system for circulating and aerating water, changing the water in the forcing containers regularly would still be advised.

Finally, the restaurant market had recovered significantly from the 2020 lull, which meant that we were able to sell everything we grew this year. Granted, these customers are of a specialty nature, but demand was strong for forcing radicchios in December of 2021 and likely will be once our endive crop starts to mature in February. We only sold tardivo radicchio to two of our restaurant accounts this winter, and that was all we could keep up with. This suggests that there are significant market opportunities for these crops in the specialty restaurant space. Furthermore, these crops would offer an eye-catching display with an interesting narrative that could also be attractive for farmers market sales.

All in all, 2021 was a good year for growing these crops. We will see how Belgian endive performs in the next few months, but this project seems like it will achieve all of its goals of diversifying the winter crop mix for Midwest growers while increasing the value and margin of winter sales.


Project Outcomes

1 Farmers changed or adopted a practice
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.