How to Grow and Dye with Weld

Weld (Reseda luteola) also known as Dyer’s Rocket is a traditional dye plant native to Europe and Central Asia. Weld produces a brilliant yellow dye thanks to a flavonoid compound called Luteolin. This bright yellow was often over-dyed with the blue dye Woad to produce “Lincoln Green” the famous hue worn by the legendary Robin Hood and his Merry Men.

This has been my first year successfully growing weld and I couldn’t be happier with the results. I tried growing weld last year in the spring but did not have much success, very few of the seeds germinated, and the few plants that did emerge eventually withered and died before getting very big. This year I ordered my seeds from the wonderful dye farm and supplier Two Looms Textiles in Washington State and planted them in late winter since my climate has such hot dry summers. I direct-seeded them because weld has a large taproot and does not appreciate being transplanted. The seedlings emerged quickly and I had over-planted the area because of my low success rate last year so I had to do a lot of thinning. I also ended up transplanting a lot of the seedlings even though I knew it was a risk, because I decided to put in a raised bed where I had planted the weld originally. I had so many plants that I wasn’t worried about losing the ones I moved, and while some of them did die, the vast majority surprisingly survived the move. I definitely recommend direct seeding weld if you can, but if you do transplant, make sure to move the seedlings when they are still very small, and try to dig them out deeply without severing the tap root.

Weld is classified as a biennial which means that it puts all its energy into producing leaves the first year and then sends up a flower stalk in the second year. My weld grew into nice bushy rosettes by early spring and by May the plants had sent up flower stalks. I’m not sure if the long growing season influenced the plants to flower in the first year, or the stress of moving the plants early on might also have triggered them to flower early. I planted hollyhocks, also a biennial, nearby and they have continued to focus on leaf growth as expected and not flower, so it remains a bit of a mystery, but not one I’m complaining about as it meant that I got to dye with weld that much sooner!

The dye can be made from the leaves, stems, or flowers, but the pigment is most concentrated just as the plant begins to flower. I tested the plants while they were in the rosette stage and just as they were beginning to flower, and I tested them again once the flower heads began to form seeds. The results from the first batch (rosette and beginning to flower) were much stronger than the second batch (once the plants went to seed). Weld can be used fresh as I did for these experiments, or harvested and dried for later use. Weld makes a great spot of color in a bundle dye and prints well on iron-mordanted fabric.

Once the plants have gone to seed you can leave them in the garden to self-sow or harvest the seed heads and put them in a paper bag or other breathable container to dry. As the seed heads dry they will release hundreds of tiny dark brown seeds that can then be collected and stored.

Whether you use fresh or dried weld the process of dyeing is the same. I used fresh material and cut it into small pieces to fit into the dyepot. I simmered the mixture for a few hours, let it sit for a day, and then simmered once more. I found that using higher heat than normal produced better results. I didn’t boil the plants but I did simmer them on a higher heat and for longer than I normally do with herbaceous dyestuffs.

Once the material looked spent I strained the mixture. I didn’t have high hopes for either of the batches that I tested because the dye was such a pale murky yellow compared to other yellow dyes I’ve made using things like sourgrass or marigolds. However once I introduced the fabric and heated it for a couple hours the fibers emerged a bright yellow and I was pleasantly surprised at the results.

As you can see in the samples below, mordanting the fibers with Potassium Aluminum Sulfate (for protein fibers) or Aluminum Acetate (for cellulose fibers) produced the strongest shades. While I love using a soy milk binder with many dyes, as you can see here it doesn’t do much to enhance the yellow or green hues in the same way that an Alum mordant does. I’ve found this to be true with most of the yellow/green dyes that I’ve tested. The leftover dyebath can also be used to make a lovely bright yellow lake pigment.

I’m very pleased with the results of my first year working with weld, and I’ll definitely continue to grow and use it. I love having an easy homegrown yellow at my fingertips and once my madder comes to maturity next year I’ll have all three of the “ancient primaries” weld (yellow), indigo (blue), and madder (red) growing in the garden to make an infinite rainbow of natural color! If you’ve been thinking of adding weld to your natural color palette I highly recommend it.