Richters InfoSheet D2701  

Fibre Flax Planting and Processing Instructions

The outer fibres of the flax plant, Linum usitatissimum, are used to make linen. Flax is a cool season, early maturing plant. It does best in temperatures of 10-27� C (50-80� F) until the blooming stage and then hot, dry weather is best for threshing and drying the straw.

Site Selection and Preparation

Flax requires an open site with wind and sun exposure. Avoid planting under trees or near tall crops, fences or hedges that may shade the plants. Flax will grow in a variety of soils, but sandy clay loams of pH 5-7 work best.

If possible prepare the beds for seeding the previous autumn, removing weeds, rocks and debris. You may not need to fertilize if the bed is new. If you do decide to fertilize, use a well-composted manure applied lightly. Too much nitrogen (N) reduces fibre quality and increases the risk of lodging or falling over in heavy rains. On the other hand, phosphorus (P) improves root development and potash (K) is required for good fibre development. Typically farmers apply nutrients at the following rates per hectare 0-40 kg nitrogen, 70-110 kg phosphate, and 70-100 kg potash. (N.B. 1 kg per hectare = 1 lb per acre.)

Seed Selection

Do not plant oilseed flax varieties; these produce poor quality fibres. It is important to get a variety that is bred specifically for fibre production. The variety ‘Regina’ is a standard fibre variety from Northern Europe with white flowers. It grows to 60 cm (24 in.) in height.

Sowing

Flax matures in 90-100 days. Flax seed is sown when the danger of severe frost is over. In northern United States and southern Canada, sowing in late April or early May is optimal. The seeds germinate in about two weeks.

Do not sow too thinly otherwise plants will produce too many branches and a coarse and inferior fibre will result. The ideal plant density is 2,000 plants per square meter (190 per sq. ft.). At this density the stems should be straight, 1-2 mm (1/16") in diameter, with only 5-6 flowers at the top. To get this plant density, sow 12-16 grams per square meter (1.1-1.5 grams per sq. ft.) or 50-65 kg per acre.

Seeds may be broadcast or sown in rows. Broadcasting helps to keep branching to a minimum, and is practical for home gardeners, but for farmers row seeding gives better control over plant spacing and allows for mechanization.

Weed Control

Flax competes poorly against weeds. Weeds depress fibre yields and make it difficult to harvest the straw. Early seedbed preparation gives weeds time to germinate so that a light tillage prior to sowing helps to reduce weeds. A thorough weeding when flax plants are 15-20 cm (6-8 in.) high helps, but avoid weeding when plants are taller or they may not recover from the damage of walking through the patch.

Pests and Diseases

Flax is bothered by few diseases and pests. Human and animal traffic can damage plants and should be minimized.

Irrigation

Irrigation by sprinkler may be necessary during droughts, but otherwise watering is not necessary once the plants are established. Do not irrigate once flowering begins in order to prevent the chance of lodging.

Harvesting

The flowers appear 60 days after planting, followed by the "boll" or seed capsule. About 80-100 days after planting, when the seeds are quite ripe, the plants are ready for pulling. If they are pulled too soon there will be too much waste in the scutching and hackling processing steps. If they are pulled too late, the fibre will be too coarse. The best time is when the seeds are beginning to change from pale green to a pale brown colour and the stalks will be yellow two-thirds up. Once the plants are ready, they must be pulled immediately, delaying not even a day.

The plants are pulled, roots and all, to give the maximum length of fibre. Plants of similar length can be bundled together, keeping the sheaves even at the root end as much as possible. Sheaves of plants 40-50 cm (18-20 in.) in circumference are tied with twine and stood against each other in groups of 10-12 sheaves to dry. It takes about a week in good weather to dry the plants. The sheaves can tolerate some rain, but if rain is heavy or if you must harvest in rain, you must bring the crop indoors to dry.
Typical dry straw yields are 1600-2800 kg per acre. About 15-20% of that, or 240-560 kg/acre, is extractable fibre.

Rippling

Once the sheaves are dry the seeds must be removed by a ‘rippler’. This is a board studded with sharp spikes about 30-45 cm (12-18 in.) long arranged like the teeth of a comb 5 mm (1/4 in.) apart. The sheaves are drawn through the rippler to separate the seed heads from the stems.

Retting

In order to release the soft outer fibres from the stems for spinning, the inner wooden core must be ‘retted’, or rotted, in one of several ways.

Dew retting. The sheaves are untied and the flax is spread out in even rows on grass for 15-20 days. The grass should be mowed to 4-5 cm (1.5-2 in.) high. The flax should be turned once daily to ensure the even exposure of the fibres to the effect of the sun, rain and dew. In dry weather when the flax shows signs of drying out and becoming brittle the flax is watered lightly with soft water in the early morning or late evening.

Water retting. The flax is retted in streams, open tanks or ponds. The best control over the retting process occurs in open tanks such as an old bath tub. The flax straw bundles are weighted down to keep them submerged. At 27� C (80� F) water will ret the flax in 5-7 days, while below 20�C (70� F) retting can take up to 2-3 weeks. The longer time is not harmful.

With each method the flax should be tested daily to determine when the retting process is complete. Too little retting will make the flax difficult to break. Too much retting and the fibres will be weak. The root end of the flax should split and begin to show the inner fibres. The most reliable test is to break and scutch a small dried sample.

After retting is complete, lay a thin layer of flax straw on grass to cure and bleach it. Turn the fibres once a day for even exposure. Retted flax will dry in 2-3 days in sun a breeze.

Breaking

The next three steps complete the separation of the fibres from the stalks. ‘Breaking’ is a process that completely smashes the woody core of the stems into tiny fragments. A wooden device called a ‘break’ is used for this purpose. It is a fixed frame to which is attached a chopping frame attached at one end to the fixed frame. By the handle at the other end, the chopping frame is brought down sharply on a handful of retted flax. This is repeated over the entire length of the flax stems until most of the brittle pith and cuticle gives away leaving the long band of fibre intact. A fluted mallet can be used to break the flax also, but a break makes the job much easier.

If the flax straw does not break completely, the batch will have to be retted further.

Scutching

‘Scutching’ completes the removal of the broken stalk from the fibre. A scutching board is a smooth wooden plank held upright on a base; it is about 35 cm (14 in) wide and 1.2 m (4ft) high. A scutching knife resembles a large butter knife or paddle. It is made of smooth wood free of knots. With the left hand a handful of broken flax is laid over the top of the scutching board so that the stalks lie against the side of the board and the right hand the scutching knife is used to repeatedly scrape and beat the stalks until all of the woody portions (the ‘boon’) separate and fall away from the fibres.

If retting is incomplete the heavy scutching needed to remove the boon will damage the fibres and much will be lost. It may not be possible to remove all of the boon. If the retting is overdone, the fibres will break into small useless pieces.

Hackling

‘Hackling’ is the process of separating fibres that are still clinging together. This is done with at least three different flax-combs or ‘hackles’ consisting of a board with steel spikes or needles. A coarse hackle of spikes spaced about 2-3 spikes per square inch. A medium hackle with spikes spaced 16-20 per square inch. And a fine hackle of fine needles in close rows about 80-100 per square inch.

The flax is repeatedly drawn lightly across the top of the hackle starting with the coarse one and finishing with the fine one. The hackles will separate and split the fibres in the fibre glands into finer and finer filaments. Left behind in the hackle will be shorter, coarser bits called the ‘tow’ that is saved to be spun into tow yarn. Fine yarn is spun from the ‘line’ or the fine hackled flax that results from the hackling process. A good hackler will get 55% fine hackled flax, 40% ‘tow’, and 5% loss.

Spinning and Dyeing

The fine line flax is now ready for spinning. It should be twisted, folded in half and allowed to bend around itself like a skein of wool, and it can be stored this way indefinitely. Mark the root and blossom ends because this is important when spinning.

Flax is one of the roughest of the vegetable fibres and success in dyeing it depends on how it is prepared. It is best spun and hanked before mordanting and dyeing. It is then treated like wool, but with higher temperatures and longer simmering in the dyebath.

More Information

Atton, Mavis (1988). Flax Culture: From Flower to Fabric. The Ginger Press, Owen Sound, Ontario, pp. 96.

Heinrich, Linda (2010). Linen: From Flax Seed to Woven Cloth. Schiffer Publishing, Atglen, PA, pp. 256.

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