Flax - Sowing

Plot sown in rows

 Plot sown by hand

The research I've done so far has made me realize how complex this little plant is and how the quality of the flax we'll get depends almost exclusively on what is done at the time of sowing, and well, also on a series of meteorological factors that we can't control.

Sowing time and density are the two crucial factors.
I'll leave the question of density for later, because it's easier to explain with pictures of the plants already grown.

As for the sowing season, in the region where we are (the north coast), it can start from mid-March. Inland, it might be a little later.
The important thing is to wait until the intense cold and frosts are over - if the weather is too cold, the plant won't grow.
However, if the weather is too hot, it speeds up the flax's vegetative cycle and it grows too quickly, forming lower and more branched plants - something we don't want either, as branching breaks down the fibers and we end up with short, lower quality fibers.
What we're ideally looking for is a mild temperature and a balance of water, so that the flax can grow at a constant rate, and this only happens in early spring. Inland, the season seems to me to be even shorter, as the cold takes longer to fade and the heat sets in more intensely, earlier.

As I mentioned earlier, our flax was sown much later than it should have been, on April 23rd, but that's all that was possible.
We sowed Galician flax from Ponte de Lima.

Part of the plots were sown in a row (spaced about 10cm apart) and the other by hand.
In flax, hand sowing is usually done manualy, but we wanted to try it both ways because there were several issues to understand. On the one hand, we thought that sowing in a row would allow us to distinguish more clearly between the flax and the weeds in the initial growth phase, so that we could clear the land. On the other hand, as the flax is supposed to have a relatively even distribution in the field (which goes back to the question of the density of the sowing), it makes perfect sense to sow in a row and, in fact, this is how it is traditionally done.
Once the seed has been spread, the area should be covered using a harrow or, when it's a very small area like the one we sow, simply a rake.
The flax seed is small and should be buried to a depth of about 1 cm.
Next, you need to compact the soil a little, to snug the soil up to the seed and also to create a “siphon” effect - the compaction will pump the moisture out of the bottom layer and no watering is needed at this early stage. Once again, as the area we sowed is quite small, we didn't even use a roller to compact it - we just beat the soil well.

The BPGV seed has a germination rate of 95%. But in addition to the 5% that naturally won't germinate, Eng.Silva tells us that 20% of the seeds that are able to germinate will also fail due to other factors: for example, because they end up being buried too deep, or because they stay too far up and are eaten by birds.

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[23.04.2015 / This post refers to the research and activities carried out as part of the Saber Fazer program at Serralves ]