Natural Dye Cultivation Series: Sulfur Cosmos
Sulfur Cosmos (Cosmos sulphureous) are a wonderful addition to the natural dye garden. The bright orange flowers have a sweet peppery smell and are a pollinators delight. Of all the flowers I grow, sulfur cosmos are the most pleasant to harvest because the plants grow to just the perfect chest height for harvesting—no bending required : )
Quick Facts:
Annual
Germination time: 7-14 days
Seed planting depth: 1/8”
Light: full sun
Spacing: 9-12”
Days to flower: 75-90
Plant height: 4-5’
CULTIVATION
I’ve experimented with both direct seeding into the garden and with transplanting and prefer the transplanting method for sulfur cosmos. The direct seed method works fine but transplanting gives me slightly earlier blooms. I start the seeds indoors under grow lights in early April about 8 weeks before our last average frost date and once the danger of frost has passed I transplant the seedlings out to the garden spacing them about 12” apart. The plants acclimate relatively quickly and begin to put out noticeable growth within 2-3 weeks.
HARVESTING
By late July the first blooms are happening and I begin harvesting right away to promote the plants to continue setting blooms. I harvest consistently every 2-3 days throughout the season until the frost comes along and puts a stop to it. Dedicated consistent harvesting yields the most blooms.
I plan to write a blog post soon to share how I dry and cure dye flowers so stay tuned for that. If you’re looking for information about natural dyeing with sulfur cosmos, I shared some of my favorite methods and dye flower recipes in this post, and for more extensive information about achieving the most colorfast shades and how to shift flower colors with iron and indigo you can purchase this recipe PDF I wrote. Be sure to check out all the dye flower seeds and natural dyes we offer in our shop. Link to our Sulfur Cosmos seeds below. Cheers!
Sulfur Cosmos
(Cosmos sulphureus)
Please note that our 2025 crop of Sulfur Cosmos are mostly yellow. After testing them out we discovered that they yield a beautiful coral-orange color (shown in the third photo).
Sulfur Cosmos yield incredible shades from bright orange, to warm orangey browns, to dark browns depending on the fiber type and mordant used. They can be used for bundle dyeing and eco-printing experiments or to set up an immersion dye bath. Be sure to check out my resources linked below.
Available in 4 sizes this year! Select either 50 grams, 100 grams, 1/2 pound, and wholesale 1 pound options from the dropdown menu.
Grown, harvested, and cured by Sara here in southwestern Colorado on Ancient Future Farm. Our family has been tending this land and soil with regenerative growing methods since 2005. Our soil is nurtured through extensive cover cropping and our crops are fertilized with compost that we make right here on site. We never use synthetic chemicals such as herbicides, pesticides, chemical fertilizers, or fungicides. Our dye flowers are harvested every day by hand when they reach their optimal potential and then carefully cured in our curing room out of direct sunlight. All of our natural dyestuffs are packaged in heat sealed envelopes to keep them fresh. For best results we recommend using them within a year.
Resources:
