PNW Landscape Plant Guide

brought to you by the plant geeks at Calendula Farm

True Indigo (Indigofera tinctoria)

Three plants around the world are primarily used to create indigo dye. They all have long histories of use by humans for dye extraction that go back many thousands of years. The one from European history is known as Woad (Isatis tinctoria), the one used in Japan and Southeast Asia is known in Japanese as Ko-sen-bon (Persicaria tinctoria), and the one used in India is known as True Indigo in the West and Neel in Hindi (Indigofera tinctoria). True indigo has the longest-known history of use, hence the name.

True Indigo is in the pea family (Woad is in the brassica family and Japanese Indigo is in the buckwheat family) and is a pretty, light, and airy shrub that grows to 3-5 feet tall and a bit wider. Small delicate leaves are very neatly ordered along very slender branches that arch up, over, and out. Starting sometime in June, slender cone-shaped clusters of blooms appear all over with bright pink tiny flowers opening successively from bottom to top. This carries on non-stop to mid-winter (here in the mild PNW). Pollinators of all sorts love it. Hummers especially dig it in December when little else is available. It is happy in full sun to little direct sun + bright ambient light.

To make the dye, all of the above-ground parts are put in water to ferment for a few days. Then calcium hydroxide (Pickling Lime) is added and the mix is aerated for a while, and voila, you can start turning everything blue.

Find them at our nursery 10-5 Tuesday-Sunday.