Flax Season is Springing Ahead in 2025, and other news!

But first, I realized that I never put up a blog about the linen flax processing demo at last fall's Harvest Festival at Gale Woods Farm (an educational farm in the Twin Cities Three Rivers Park District). It was a fabulous event! Absolutely packed with visitors. I send out a thank you to all who dropped by my demonstration area to learn how linen flax is mechanically processed from stalk to spinnable fiber. The farm plans to repeat the event this fall, and I'll continue to blog about this year's crop (yes, there will be one—see the end of this blog post) as the season comes nearer.

I was so busy demonstrating that I never had a chance to photograph the activity, but here are images of my demonstration area:

Perennial Flax and the University of Minnesota

Now, I want to catch you up on what has happened over the past few months. Late last year, the University of Minnesota Department of Horticultural Science contracted with me to process some of their experimental perennial flax. The goal was to see how three different varieties might be processed into textile fiber. 

Since the work needed to occur during the winter months, I put a large cattle feeder tub in my basement, put an aquarium heater into the tub, filled the tub with water, and placed three groups of experimental perennial stalks into the tub. (It was actually a re-ret of stalks that had been retted for about a week at the U of M but still were not retted enough for mechanical processing.)

Cattle feeder tub with an aquarium heater in the center.

The flax stalks were placed into the water to soak. I placed dish tubs filled with water to weigh down the flax stalks so they would be fully submerged in the vat.

The process took a total of 14 days, with 12 of those at a steady temperature of 88° F. After the first day, the vat started to show a skim of bacterial matter on the water’s surface. Yay! That was a good sign things were happening. 

The bubbles show bacterial action happening in the vat. The rotting of the stalks has begun!

Shortly after that, the smell started. Ooh la la! Our basement stunk! But it was all for the cause of science! Having a husband who doesn’t seem to have a sense of smell helped! My dog, on the other hand, thought the vat was really yummy smelling, so I needed to take special measures to keep her from drinking the vat water. 

When the stalks showed signs of breaking down, I cooled the vat down for 24 hours, pulled the stalks, rinsed them, and set them out to dry on clothes racks.

I kept the groups tied during the entire retting and drying process in order to know which variety was which. I loosened the ties a bit while they were drying to allow air to get around the stalks.

After about a week of drying, they were ready to break and mechanically process. Perennial flax stalks are known to be much stiffer and harder to break than linen (annual flax) stalks, and that proved to be true. The cellular structure of perennial flax is different than what is found in linen flax. Nevertheless, I was able to break the stalks down and ultimately release fibers. The tops, where the flowers emerge from branches, broke off, even crumbled, into waste matter. That was not surprising since the flowering branches are the weakest part of a perennial flax stalk. And since there are more flowers in the perennial varieties of flax than in linen flax, the branches that carry the flowers create several breaking points in the stalk.

The stalks were very firm before breaking them.

Annual (linen) flax is pulled when harvested, roots and all, but perennial flax is cut at the ground level to allow it to regrow from the root crown, so there were no roots on these perennial stalks. What remained was the main stalk to finish breaking, scutching (scraping off the boon—the woody matter that contains the fibers), and hackling the remaining stalk matter into fine fibers that could be spun.

Perennial flax after scutching off the boon with a scutching knife (the knife is the wooden tool hanging off the side of the scutching board).

Two of the three varieties showed similar qualities in color and fiber length. They were a dark tan color and fairly short—twelve inches or so. 

I used three hackles—coarse, medium, and fine—to hackle the scutched fibers. This image is of the perennial flax that was the longest and finest of all the varieties. The tow that resulted from the hackling process is in front. There was a LOT of tow! That can be blended with wool for spinning or used in a variety of other ways. Firestarters and paper making are some uses!

The third variety, shown above, was quite nice as a potential textile fiber. Although it was shorter than a typical linen flax fiber, about 18 inches long, it was lighter in color and fine enough for spinning.

I will continue to test additional perennial varieties this spring and post the results here as the University allows the information to be shared.

Linen Flax at Gale Woods in 2025

Back to the annual variety: linen flax! Another plot of linen flax is being planned for this spring at Gale Woods Farm. I have been invited to champion it again this year, perhaps once more as a volunteer if funding for a contract position doesn't come through. (To potentially not be funded for my time is disappointing, but I am committed to seeing another crop come into bloom and having the opportunity to share this wonderful fiber with our community!)

The first step of the work has begun! A germination test of seeds from last year's stalks was started at the farm by the garden supervisor, Greg. As of April 14^th, 110 of 130 seeds from last year’s rippled flax stalks have sprouted in a flat in the farm greenhouse! We are happy with that response. 

This image was from April 11th, when about 3/4s of the linen flax seeds had germinated. More came up in the following days.

There are even several stalks coming up under the greenhouse table rack, where the seeds fell into the underlying soil during the rippling process last fall. Since they are “volunteers,” they are growing quickly in the warm greenhouse environment and are already a few inches tall! Unfortunately, many will need to be sacrificed so the farm staff can get the garden crops started in flats on the table rack. I plan to rescue a few of these to put in pots at my house. I am giving up on trying to grow linen flax in the ground around my home since I have too much shade for a successful crop. I can find a sunny place in my driveway for pots, though.

One More Item to Share

Recently, I was asked to write an article about linen flax in Norway for the Norwegian Textile Letter, an international publication based in the Twin Cities. In the article "Linen Flax in Norway: Past, Present, Future,” along with other pertinent Norwegian flax news, I talk about how Norway is taking part in the Grow One Square Meter of Flax movement that is sweeping the world! Enjoy the article! https://norwegiantextileletter.com/article/flax-in-norway/

A Perennial Reveal

Those following my blog may recall that the University of Minnesota Horticultural Research folks visited Gale Woods Farm a couple of months ago to see the linen flax crop. They gave me a few bundles of their perennial flax, which they had retted, to try to process mechanically. I finally got around to doing that, and here is the result:

I first tried to break the flax with my flax brake and found the stalks as hard as steel! To me, that indicated that either the perennial flax needed more retting or the stalks would need another method of breaking. I leaned toward requiring a longer retting than the 1–2 weeks that the University had already done. 

So, I put one bundle into my puppy pool to soak a bit longer. I don't have photos of the flax in the pool—it was rather unexciting, to be honest, since there was no obvious biological action happening—at least the bubbling you typically see with retting flax was very minor. The weather was warm (mostly 80 degrees), but my yard had limited sun, so it was not as ideal as the Gale Woods greenhouse. Nevertheless, after 11 days, I finally saw some release in the fiber strands as I bent the stalks. It was time to pull the stalks, rinse them, and let them dry as a re-test of the mechanical processing!

I took a small handful of stalks to break since they were still very stiff and did not easily break in the brake. (I don't know why brakes are not spelled "break" since that is what the equipment does, but that's the nomenclature for that piece of equipment!)

The stalks were finally breakable! There are certainly differences between the linen variety of flax grown at Gale Woods Farm and this perennial variety grown for seed and straw use. Besides the length of the stalks (this variety of perennial flax is about a foot shorter than the linen flax), there is obviously something different about the cellular structure between the varieties. I observed that the boon (woody matter of the stem) of the perennial variety hangs onto the fiber strands much more tightly than it did in the linen flax variety.  

I was able to break enough fiber to scutch and hackle. Above is what the stalks looked like after breaking. 

There is a substantial amount of boon to scrape off after breaking—more than with the linen variety of flax!

Success! After putting the broken and scutched (scraped) fiber through three grades of hackles (coarse to fine), I ended up with a small bundle of short but spinnable fibers. They are a bit coarse, although they can be spun with a tow-spinning method. (That comment is for all of you flax spinners. You will know what I mean!)

My conclusion is that, yes, you can grow perennial flax for its fiber content. Although it takes longer to ret and mechanically process, you can get some short, spinnable fibers. It won't create fine linen thread, though. I plan to try spinning this into a wool/linen blend yarn, which is more suited to a shorter fiber preparation called "woolsey," also called "linsey-woolsey!"

Now, I'm going back to spinning some of the Gale Woods linen flax, so I have samples of that for the Fall Fest at Gale Woods Farm on October 13th! I hope to see you there!

One, Two, Three, Four – Ret!

To recap, the Gale Woods Farm linen flax retting process began on Friday, September 6. The following days were very active, and I waited to post about what had been happening until I could gather everything into one post. So here goes…

Putting on My Citizen Scientist Cap 

I closely recorded the subsequent retting activity by recording temperatures and visually/physically inspecting the retting stalks daily. Here are the results:

DAY ONE

Saturday, September 7, 2024, 1 PM (this was 24 hours after the stalks were put in the vats)

Air temperature: 65 degrees Fahrenheit.

Greenhouse temperature: 96 degrees Fahrenheit.

I did not test the vat temperature that day, but both vats had significant biological action (bubbling). Look at the video below to see how active the bubbles are!

DAY TWO

Sunday, September 8, 2024, 12:15 PM

Air temperature: 69 degrees Fahrenheit.

Greenhouse temperature: 96 degrees Fahrenheit.

Vat temperatures: 82 degrees Fahrenheit.

The vats are still actively bubbling and have a skim of what looks like an oily biological material.

I drained about half the water out of the vats and refilled them. I also opened the greenhouse walls for more ventilation since the weather forecast was for higher temperatures and direct sun for the next two days. 

DAY THREE

Monday, September 9, 2024, 3 PM

Air temperature: 79 degrees Fahrenheit.

Greenhouse temperature: 98 degrees Fahrenheit.

Vat temperatures: 88 degrees Fahrenheit.

The stalks are getting closer to being retted. Some of the surfaces of the stalks are starting to rub loose, although the stalks are still not breaking easily.

DAY FOUR

Tuesday, September 10, 2024, 3 PM

Air temperature: 76 degrees Fahrenheit.

Greenhouse temperature: 90 degrees Fahrenheit.

Vat temperatures: 88 degrees Fahrenheit.

(Out of curiosity, I tested the vats for their pH numbers to be sure they were holding a more acidic nature. The farm water tested at 8, which is slightly alkaline. The vats tested at 6, which is slightly acidic and close to the goal of 5.5. That was good news!)

 

I pulled out some stalks, and they showed signs of being retted (see the video below). When retted, the linen fibers pull loose from the stalk, and the woody matter (the "boon") drops off. The fibers we want to make linen thread are the thin ones you see in the video.

As a precaution, I pulled out a few more stalks to dry in the greenhouse overnight to test for their breakage the following day. To not over-ret the stalks in the vats, I drained the vats and let the stalks rest in the emptied vats just in case I needed to refill them in the morning to continue the retting process. (When the water is removed, the anaerobic bacteria dies, and the retting action stops. But when water is added again, the retting action continues.)

The Morning of Wednesday, September 11, 2024

To avoid hauling my flax brake to the farm, I used a rolling pin to test-break the dried stalks. I excitedly found that they were well-retted and ready to dry! 

I gently rinsed the stalks that had been resting overnight in the vats and laid them out to dry on the greenhouse racks.

The biological processing is done!

The next day, I checked on the drying flax stalks and found a monarch butterfly flittering along the flax in the greenhouse, perhaps enjoying the residue from the biological processing!

Oh, but wait,… the crop was not entirely done! 

There were still 60 bundles of the flax crop that were saved for seed remaining to ret! 

The farm staff tried to ripple (take off) the seeds of those stalks, although most of the seeds had fallen out of the capsules by the time they pulled them off the fence where they were drying. The conclusion was that drying stalks on a fence line to save for seed was not optimal. Either the stalks should have been left longer in the field to dry upright (although, due to bad weather, that couldn’t happen this year) or risk a lower seed yield and harvest and ripple all the seeds when the stalks were ready to be pulled for linen. The general conclusion was to, in the future, ripple all of them during the linen stalk harvest since the first rippling provided many viable seeds.

 

The staff put these last bundles in a single vat on Friday, September 13. What followed was a very warm weekend, so I visited the vat the next day to drain it halfway and refill it.

I didn’t bring my vat thermometer, although the vat was in an active bubbling state, and the stalks were not fully retted. Based on the experience of the previous vats, I took a chance that the stalks would not be retted in two days, so I didn’t check the vat the next day.

 

Monday, September 16, 2024, Noon

The last batch of stalks was fully retted! This was only three days into the vat soaking! But since the greenhouse temperature was quite warm during this period, in the lower nineties, I suspect the vat had moved along faster. I drained the vat, rinsed the stalks, and laid them out to dry. 

Some of the stalks in this last batch still had a green hue. That is a mystery. How could they still contain chlorophyll after all this time? I visited the farm a couple of days later when the flax was nearly fully dry, and the green hue had almost completely disappeared.

 

NOW, finally, the biological processing step is DONE for the entire crop! 

What an experience this has been! After all this dedicated care and time, it feels so great to have a successful crop. 

I want to acknowledge the Gale Woods Farm garden team for all their support this summer. A crop of this size needed a village to make it happen. My heartfelt thank you goes to Katie, Lydia, Lexied, Cat, Nadine, and especially Greg, the garden supervisor.

 

So, what’s next? 

I will mechanically process a few flax bundles before the farm’s Fall Fest, a public-invited, free event at Gale Woods Farm, on October 13. There, I plan to show examples of processed flax, from the stalk and biologically and mechanically processed fiber, to spun fiber. If my time permits, I may also have a woven linen piece from the handspun flax. I'll also demonstrate the mechanical processing steps during the event, so come and see that for yourself! Here’s a link to more Fall Fest information: https://www.threeriversparks.org/fallfest

 

If you can’t attend the event, return here to see the mechanical processing steps, which I will post next.

I plan to keep this Summer of Linen Flax thread alive, at least through the next month or so and will see what the future holds for additional discoveries to share in this adventure with linen flax. Thanks for coming along with me this summer!

 

 

 

The Flax Vat Ret Has Begun!

Today, Friday, September 6, we began retting the Gale Woods linen flax. This is precisely four weeks after we harvested the flax and two weeks after we rippled it (removed the seed capsules). The stalks were a beautiful light brown, and most no longer had the green tint mentioned in my last blog.

 

We started with three vats but realized only two would be needed, so we moved flax from the smallest vat to the two larger ones. (The flax doesn’t need to be free-floating in the vats; it just needs to be fully submerged, and two vats were enough for that.)

 

When filling the vats with the stalks, the flax must be placed with the root ends together and in alignment. This is important for the remaining processing steps.

Large pavement blocks were placed on top of the flax in the vats, but we found that additional weights were needed to fully submerge the stalks. A few field rocks did the trick!

The temperature in the greenhouse was 70 degrees when we started the process (the "live" reading is on the right in the photo). The water was cooler, maybe 50–60 degrees, but it will warm up quickly as the sun hits the greenhouse and the ambient temperature increases. The weather temperature is supposed to be in the 80s during the next week, so I expect the ret to move along quickly. I will be monitoring the vats every day, draining some of the water as the anaerobic bacteria (bacteria that thrives in water) does its work (the bacteria make the water bubble and smell awful!), and photographing the progress up to the point of the flax being well-retted. 

My next post will show the retting results, so keep in touch!

 

 

A Rippling Good Time Was Had!

The flax stalks had been drying on the fence line for nearly two weeks, but the farm staff moved them into the greenhouse because of another bout of rainy and stormy weather. 

That was a good move since we were able to ripple (remove) the seed ovules (the capsules containing the seeds) inside the greenhouse last Friday, August 23. That was two weeks after the harvest and the typical drying period before rippling. A few of the stalks had a green hue in the middle of the bundles, so perhaps they were not fully dry. But we moved ahead with the rippling anyway.

Since we didn’t have a “true” seed-removing hackle, we used an open-tined garden rake as the first tool to pull off the capsules and followed it up with a wool hackle (used in preparing wool for worsted spun fiber—something I had in my teaching tools). This two-step process worked quite well.

 

After three hours of rippling with four of us rotating between the hackles, we ended up with a LOT of seed capsules. Considering the capsules average five seeds per capsule, we undoubtedly had a lot of seeds to try germinating and sowing for next year. 

Greg, the garden supervisor, took aside about two cups of capsules and debris and winnowed it down (cleaned out the debris) to about a half cup of seed. In the photo, he is letting the wind blow away the lightweight chaff as the heavier seeds drop into the bucket. There wasn't enough time to winnow all the seeds that day, but with what was gathered in the tarp under the rippling hackles, there should be more than enough seeds to give it a go for another crop. We also left a quarter of the stalks in the field dedicated to harvest for seeds, not for linen fiber. So, there should be no worries about having enough seeds for next year’s crop!

As I write this, an UPDATE! The winnowing has been completed, and there were 5.5 pounds of seed just in the approximately 125 lineal feet of harvested flax! Considering that we started out with 1.5 pounds for the entire 150 lineal feet, that is a huge seed yield!

The winnowed seeds show a variety of maturity levels. The lighter-colored seeds are probably not mature enough for sowing next year, while the mature flax seeds are medium brown. Interestingly, based on my research, the stalks with the less mature seeds will likely have finer flax fiber, so harvesting the stalks at this stage should be good for our fiber goals. What is left in the field will be more suited for next year’s seed crop since those stalks, maturing longer, will be too woody for good linen fiber. Greg will do a germination test of the seeds to see if the seeds from the stalks still left in the field will germinate better. It will be interesting to discover the results!

The rippled flax stalks are now resting in the greenhouse while we await the next step: retting (rotting) the rippled stalks. (Check out that corn stalk in the middle! It was from a rogue kernel of corn that germinated in the greenhouse and was probably the tallest corn stalk at the farm this year due to the poor growing conditions. That is why they left it standing! 😂) 

We are waiting until after Labor Day weekend (the first week of September) to begin the retting process. I am crossing my fingers that we will have warm weather into September since we are retting the flax outdoors, probably in vats or laying them in a field to dew-ret if we cannot find large enough vats. Warm weather is essential to keep a warm environment for retting in a vat or field. 

The stalks need to be retted and thoroughly dried before the final mechanical step, which is processing them into fiber. Time is getting tight! We have a deadline of October 13—the Gale Woods Fall Fest day (10 AM – 4 PM), when I will demonstrate those last steps—hopefully with the Gale Woods Linen Flax!

A Visit from University Researchers and 

Flax Harvest at Gale Woods Farm!

A couple of weeks ago, three researchers from the University of Minnesota Department of Horticulture Science visited the Gale Woods Farm flax crop. The U of M has been testing perennial seed flax (not linen flax) to develop the most suitable seed flax for the Upper Midwest region. I first met one of their researchers, Matt, after I gave a presentation and demonstration about linen flax in April at the Weaver’s Guild of Minnesota. He became intrigued by the Gale Woods Farm linen flax project I mentioned at my talk and has been following its progress. On July 29, Matt and his colleagues from the U of M traveled to Gale Woods Farm for a literal field trip to learn more about linen flax and see it growing in real life. We had such an enlightening visit sharing and comparing the different varieties of the flax species! 

 

Matt gave me a few bundles of their perennial seed flax stalks, which he had retted and dried. Note that these bundles have been cut and not pulled. (The cut end is on the left in the photo.) The crown and roots of the perennial varieties need to remain in the soil for next year’s spring growth, so they are cut. (Linen flax is an annual plant and is pulled.) I have promised to mechanically process these cut stalks with my flax processing tools to see what sort of fiber might emerge. Seed flax has many flower branches and is shorter than linen flax (these bundles are 3 feet in length, and an optimal linen flax stalk will be another foot longer), so I don’t expect to recover fiber that will be that useful for spinning unless it is blended with other fibers. But we shall see! I LOVE such real-life experimentation! 

Gale Woods Farm Harvest Day Has Happened—
Friday, August 9th!

This is what the plot looked like on August 9. It was ready to harvest!

We (the Gale Woods garden staff, a farm volunteer, and I) harvested the flax last Friday, August 9th. The harvest date snuck up on us. Most of the stalks had quickly become yellow about one-third of the way up the stalk, perhaps because of the warmer turn in the weather from the past week. Since August 9 was 94 days since the sowing on May 8 and within the 90–100 days from sowing, which is the expected growing window for linen flax, it was ready, even if some flowers were blooming on a few of the slower-growing stalks. Our harvest day just happened to be on a beautiful, cool day with a brisk wind, so it was another reason to take advantage of the perfect weather for harvesting!

 

In four hours, we pulled about three-fourths of the 150-lineal-foot plot and left the tallest last quarter of stalks to stand in the field, where they will fully mature to a brown color, and their seeds will also complete their maturation. Those stalks will then be pulled, and their seeds will be used to plant next year’s crop in hopes that they will also result in a tall crop for next year. (See them at the far end of the image above. The green plants in the pulled plot are mainly weeds left behind after the harvest! It was a weedy plot, even though you couldn't see all the weeds through the dense, tall stalks. Better preparation of a plot area in the fall will make next year's plot much cleaner. We didn't have that opportunity for this year's crop.)

Another sign that the crop is ready to harvest is the sound of the seeds bouncing inside the seed ovules (capsules). Turn up your sound to hear the gentle rattling of these ovule “maracas”!

The harvested plot yielded 157 flax bundles (“beets”), which we hung on the adjacent fence to dry with the seed end down. Hanging flax is the best way to dry the stalks since it allows the stalk and seeds to mature further, as all moisture remaining in the stalk will move to the stalk tip and the seeds during the drying process. The other method is to set them upright in “chapels” in the field (chapels are beets set upright in groups that support each other like a teepee). But because our summer has been so wet and space for the chapels to sit was challenging, hanging them was the best option. They will dry very quickly when hung and make a lovely visual along the fence line!

I drove past the fence yesterday, and in just four days, the harvested stalks have already started to dry and turn brown! 

When they are fully dry, maybe in a few more days to a week (there is no urgent timeline for the next steps), we will ripple (pull off) the seed capsules, and the stalks will be ready for retting. The farm has vats that we can use to ret the stalks in the field. Vat retting is the fastest retting method. But, since we cannot artificially heat the vat, we will need to let the ambient temperature and sun participate in the ret, which takes about a week longer than a controlled heated vat. (The other retting method is dew retting them by laying the stalks in thin layers on the ground. That usually takes at least two weeks or more and can result in an uneven ret. Besides, since ground space is also limited, that was another reason to vat ret!)

 

The stalks should be ready for rippling off the seeds sometime during the next week. Stay tuned!