FIBERuary Day 17 Flax with Michelle Parrish Part 2
Flowering and Setting Seed
Depending on the type, flax will start to bloom between 37 and 45 days after planting. Flax flowers open in the morning, and the petals fall off by mid-day. Each flower only lasts a day. Flax is indeterminate, which means that once it starts to bloom, it will keep blooming until you harvest it. For fiber, pull flax before the seeds are mature, between 90-100 days after planting. The exact timing will depend on the weather. If it’s hot and dry, the plants will mature more quickly. When you harvest, the plants will still be flowering. The bottom third to a half of the stalks will be yellow and there will be green and tan seed bolls. You may have a few mature seeds at this point, but not a lot. If you want to save some plants for seed, let them grow until the seed bolls are dark brown. Watch out for birds and rodents, as flax seeds are very oily and desirable. The seed pods can also fall off or pop open when they are ripe, so keep an eye on your seeds. Botanists consider flax self-pollinated and don’t tend to worry about cross-pollination between two types. However, flax flowers are definitely visited by nectar-hungry insects so I recommend separating types by distance or physical isolation.
Harvest and Drying
Retting is the trickiest part of the process, and judging when flax is properly retted takes experience. Retting is a controlled rotting process that releases the flax fibers from the rest of the stem. Flax is a bast fiber, meaning that the fibers are in the stem of the plant. Two traditional ways to ret are dew retting and water retting. With dew retting, you open up the dried bundles of flax and spread the straw on a grassy field in rows. You flip the rows over periodically so all sides of the plant ret evenly. Fungi slowly consume the pectins that hold the fibers to the woody material of the stalk, and also release the waxy cuticle from the outside of the stalk. The fungi occur naturally in the plants or in the soil, but not every field has the right make-up of micro-organisms conducive to dew retting. Dew retting can take several weeks and is weather dependent. If the weather is very dry, you will have to sprinkle the stalks with water. If it’s very rainy, you run the risk of rotting the stalks. When the silvery-gray fibers start to look wispy, it’s ready. My first attempt to dew ret (during a rainy, cold fall) was a disaster, and I have only done water retting since then.
With water retting, a combination of aerobic and anaerobic bacteria consume the pectins that hold together the layers of the stalk. The bacteria occur naturally on the plants. The speed at which retting occurs is dependent on temperature and water quality. Traditionally water retting was done in ponds or dammed-up sections of a stream or river. Since water-retting is a bacterial process, it makes the water quality foul. I use stock watering tanks. I have a 50 gallon tank and a 100 gallon tank. The 100 gallon tank holds a lot, but it also takes a lot of water to fill it. Water retting takes anywhere from 6 to ten days when done in the summer or early fall. I fill up the tank with water, and wait for it to off-gas (I’m on town water) overnight. I suspect that the chlorine or other chemicals in the water inhibit the growth of the bacteria. Then I submerge the bundles and weight them down with boards, bricks, or milk-crates full of buckets of water. if you don’t submerge the bundles, they will float. They need to be under at least 3 inches inches of water to ret properly. Once it’s clear the bacteria are active, change a portion of the water every day (up to a third of the water, depending whose recommendations you read). Some years I haven’t changed the water at all, in the hopes that I could speed up the process and save water. However, adding fresh water maintains a certain balance of oxygen, which I suspect leads to better retting.
Once retting is complete, I drain the tanks, rinse off the straw, and hang or lay out the bundles to dry. Be careful not to rub or agitate the bundles too much when rinsing. The loosened fibers can get tangled and then they just stick together and break off when you do to the next stages of processing. Water retting produces a lighter color fiber (yellow or white) than dew retting (silver or gray).
“Dressing” or Processing the Fiber
Once the retted straw is dry you “brake” or “break” it with a tool called a flax brake (or break). This tool looks sort of like a saw-horse, with an arm that you can swing down onto the stalks to crush them.