Why Saving Your Own Flax Seed Is Worth the Effort

Flax is one of the most generous crops a smallholder can grow. Sow it in spring and it rewards you twice over: tall, slender stems that yield beautiful pale-gold fibre for spinning and weaving, and a crop of shiny brown seeds that will sow next year's patch for nothing. Saving seed closes the loop on your growing cycle and, over a few seasons, you gradually select plants that suit your soil, your climate and your particular way of working. Varieties that ripen reliably in a wet Cornish summer or stand up to a windy Lincolnshire field will slowly come to dominate your seed stock. It is quiet, patient plant breeding, and it costs you nothing but attention.

Knowing When the Bolls Are Truly Ripe

Timing is everything with flax. The seed sits inside small round capsules called bolls, and these ripen from the bottom of the stem upwards over two or three weeks. Your signal to start watching closely is colour: bolls shift from green through yellow to a dry, papery golden-brown. When you shake a stem and hear a faint rattle, the seed inside is loose and ready.

A few practical markers to work with:

• Sound: a gentle rustle means ripe; a dull thud means the seed is still green and clinging to the boll.
• Stem colour: the lower two-thirds of the stem should be yellowing and the leaves mostly dropped.
• Seed colour: open a boll and check. Ripe seed is glossy and dark brown (or pale gold in some varieties) rather than dull and greenish.
• Weather: aim to harvest on a dry, still morning once the dew has lifted.

Do not wait until every boll on the plant has turned. Flax shatters — the ripe bolls split and fling their seed onto the ground — so a light loss at the top of the stem is far better than losing the lot. If rain is forecast, cut early and finish ripening under cover.

Harvesting and Threshing the Seed Heads

Pull or cut the stems close to the ground, keeping them in bundles of about a fist's thickness. If you want both fibre and seed, this is the moment to decide: for fibre, pull the stems whole to keep the longest possible fibre length; for seed alone, cutting is perfectly fine. Tie each bundle with twine and stand it somewhere dry and airy — a shed, a porch, a greenhouse with the door open — for a week or two. A sheet underneath catches anything that drops.

Once the bundles are bone dry, threshing is simple and satisfying:

• Rub the seed heads between your palms over a bucket until the bolls crumble.
• For larger quantities, place dried heads in a cotton pillowcase and beat it gently against a wall, or tread on it in clean wellies.
• Winnow the result by pouring it slowly between two buckets in a light breeze, or in front of a fan on its lowest setting, so the chaff blows clear.
• Pick out any remaining bits of stem by hand — a little patience here saves trouble later.

Drying Seed Thoroughly Before Storage

This is the step most often rushed, and it is the one that decides whether your seed survives to spring. Seed stored even slightly damp will heat, go mouldy, or lose viability within weeks. Spread your cleaned seed in a single layer on a tray, plate or sheet of paper in a warm, dry, well-ventilated room — not in direct sun, and never in an oven or on a radiator, as temperatures above about 40°C can damage the embryo.

Leave it for a fortnight, stirring gently each day. If your house is humid, a small sachet of silica gel in the tray helps enormously. The test for readiness is simple: bite a seed. A properly dry flax seed cracks cleanly between your teeth. If it squashes flat or bends, it is still holding moisture and needs more time. Aim for a moisture content around eight per cent.

Storing Flax Seed for Next Season

Flax seed keeps best in the dark and the cold. Once thoroughly dry, tip it into paper envelopes or small glass jars. Paper breathes, which suits seed that is not quite perfectly dry; glass with a tight lid and a silica sachet is excellent for seed you are confident about. Either way, label every container with the variety, the year and any notes on the plants it came from.

Store jars in a cool, dark cupboard, a cellar or the bottom of a fridge — somewhere steady between about 5°C and 12°C, away from mice and damp. Kept this way, flax seed will germinate well for two to three years, and often considerably longer.

If you grow more than one variety, keep them apart. Flax is largely self-pollinating, but insects can carry pollen between plants, so a separation of a hundred metres or so between varieties will keep your strains true. Before sowing next spring, test a dozen seeds on damp kitchen paper in a warm place and count how many sprout within a week. Anything above eight out of twelve and you can sow with confidence, knowing that the harvest ahead began on a dry afternoon last autumn.