My season of indigo has already begun, but yours can begin anytime! Here I will share with you my indigo season, from starting seeds to harvesting blue. Follow along as I show you what I do, but also give advice on what you can do at home with any amount of indigo plants.
I have specific goals in mind when I grow my indigo. I am harvesting a large amount of indigo to use in the studio in dye vats throughout the year. There is a lot to learn to do this; first you have to learn how to extract the indigo from the plant, then you have to learn to create a vat that will dye fiber. This will be my third season of small production-scale indigo extraction. However, the processes I will show you can be done at just about any scale.
You can start your seeds directly in the garden just about any time after your frost date. If your goal is to harvest indigo like a crop, then it's best to start seeds earlier indoors, in a greenhouse, or in a cold frame to get the most cuttings. But fear not! If you plant them later, you may just get smaller harvests.
In an indigo season, I aim to harvest my plants three times before letting them go to seed in the fall. It really depends on your seed start time and location how many you will get. If this is your first planting, rejoice in watching your plants grow and the magic of producing your own natural blue dye! It was years before I started harvesting indigo in earnest, it was a joy just to watch it grow and to witness the leaves turn my fingers blue right before my eyes.
I start my indigo season by planting my seeds in a cold frame. Here in south central Indiana (Zone 6), I started my seeds this year on March 18. I have an old glass door from a remodeling project, and my husband (being a handy kind of guy) built me a simple frame on which to set the door. It's not a raised bed, but a very basic raised frame, about 7-8" tall and the size of the door, to cover the seed bed.
I took some of the soil out of my box and put it in a bucket. I scattered my seeds fairly densely throughout the box.I put down approximately an ounce of seeds to make sure they grew in thick, but it will likely grow more starts than I will need. I sprinkled the dirt I put in the bucket on top of the seeds. I watered my seeds in, then set the glass door on top. I left the door on until the seedlings start coming in and the weather warmed up enough to give them fresh air.
If you are interested in trying a cold frame, I'm a firm believer in using what resources you have around you. Use up some old lumber, or try a Habitat Restore near you. Feel free to Google some cold frame designs, but I highly encourage you to be creative.
Once most of them sprouted (around two weeks), I let them get rained on if it's not monsoon rain, and fresh air to strengthen them (covering them up again if the weather gets cold, below 40-45ºF). If it's not raining, I water them (almost) daily until it's time to transplant them into the garden bed.
Coming up next in early May: transplanting into the garden!
For more information on starting indigo seeds: