When To Harvest Flax For Fibre | Waiting For Northern Princess
Updated: 24 hours ago
My usual flax has already been pulled and retted, but Northern Princess is still in the garden producing the occasional flower. I sowed them on the same day, beside each other, so I hadn’t expected to be here in October wondering whether one was ever going to finish. I left Northern Princess because it was shorter. I thought it needed a little more time to catch up, then a little more, until I started questioning what I thought I knew: aren't you supposed to harvest flax after it has stopped flowering?
What I'm learning is that deciding when to harvest flax for fibre means looking beyond the last flower. The lower leaves, developing seed bolls and changing stems all help tell the story. Waiting for fully ripe seed is a different decision from choosing when to pull for fibre, and those scattered flowers had rather distracted me from looking at the rest of the plant.
Growing Avian & Northern Princess Side By Side
Both varieties went into my front garden in Riddings on 20th April 2026, following the flax planting day tradition I had heard about. There was my familiar Avian from Flaxland and, this year, Northern Princess from Seeds of Scotland, growing alongside woad. I bought the new seed because I'm part of Fibreshed Scotland's Flax, Hemp & Nettle specialism group and wanted to see how another variety would grow alongside the one I already knew. It seemed a fairly straightforward experiment at the time.
Northern Princess also came with a story that took my little packet of seed far beyond Derbyshire. Irish Seed Savers' catalogue describes it as an Irish flax variety presumed to come from northern Ireland, returned from the Vavilov Institute's seed collection in Russia around 2000. Although it was an Irish variety, it had been preserved so far away. There are gaps in its early history, but something about that journey feels very close to the reasons I grow flax: the threads between people, places and the materials we might otherwise forget.
Leaving It A Little Longer
I pulled the Avian around 100 days after sowing. That is an approximate recollection, rather than a carefully recorded harvest date, but it followed the pattern I had expected. Northern Princess looked shorter, and I didn't want to pull it before it had had its chance. While the Avian moved on to retting, the process that helps release the fibres from the stem, I left its neighbour growing.
Meanwhile, the clay was doing its best impression of something you could build a house with. It was hard and cracked, and I watered as little as I thought I could get away with. I still don't know how much that helped. Growing my own textile materials brings me very close to questions about water and resources, but it doesn't always provide tidy answers. These two varieties shared a garden and a sowing day; they weren't part of a controlled trial, with measured water and neatly recorded conditions.
By mid-October, Northern Princess still had scattered flowers. Not a whole patch in full bloom, just enough to keep me hesitating. Had the summer interrupted it? Was it catching up now? Had I mistaken a shorter plant for an unfinished one?
Was It The Summer?
I wondered whether its presumed northern Irish origins meant Northern Princess would prefer wetter conditions. It was a tempting explanation for what I was seeing, but its history cannot tell me that on its own. Seeds of Scotland describes Northern Princess as the most productive variety in its 2024 flax trial, which is encouraging, but that doesn't tell me what to expect in my cracked Derbyshire clay.
Research shows that heat can change how flax flowers. In a study of heat stress in flax, researchers exposed a different variety, Normandy, to temperatures reaching 40°C while keeping the plants well watered. Seed set fell during the heat stress, and afterwards the plants produced more flowers, extending their flowering period. That helped me understand how a plant might keep flowering after difficult conditions, but it wasn't a trial of Northern Princess, and it wasn't my garden. It gives me something to think about, not proof, of why mine stayed in the ground so much longer.
Should I Harvest Flax If It's Still Flowering?
A few remaining flowers aren't enough on their own to decide whether to keep waiting. Flaxland's growing and harvesting guidance describes the changes to watch after flowering: the seed bolls swell, the lower leaves turn yellow and fall, and the stems become firmer. Its guidance puts harvest at roughly 100 days from sowing, commonly four to six weeks after flowering, but those timings need to be read alongside what is happening to the plants.
I had become so occupied with Northern Princess's height and those last flowers that I needed to look at the rest of it. Being shorter doesn't necessarily mean a plant needs longer. Whether my extra patience has helped or hindered the fibre is something I won't know until I process it. I can't honestly finish this story with a verdict on which variety was better.
For now, this is another piece of learning from my Riddings Community Flax Project: I sowed two varieties of flax on the same day and found myself having to question how I decided they were ready. If you're thinking of growing your own flax next season, my guide to growing flax at home takes you through the basics. And if you have grown Northern Princess, I would love to hear when you finally pulled yours. Is it still offering you the odd flower too?
Read what happened next: How To Pull Flax For Fibre | Harvesting & Rippling Northern Princess In Derbyshire
