One of the most treasured and rare colors in the plant world is blue. Indigo was so valued that colonists in the United States used it as a trade crop.
After extracting the color from the natural tannins in the plant material, you can use it to dye yarns and fabrics. To create the deepest and longest-lasting colors, use plenty of plant material, allow the dye bath to steep for several hours, and use appropriate mordants to set the colors in the fabric.
Cornflower, Centaurea cyanus, is an annual plant native to Europe with intense blue flowers. It is also known as Bachelor's Button or Blue Bottle. As a native wildflower species, it is now endangered due to agricultural growth. However, it has been cultivated to become a rather common garden flower.
To create a dye bath, the petals are boiled with alum added to the water. The dye is then strained and is ready to color cotton or wool fabric or yarn.
Dogwood Bark and Fruit
There is nothing blue on the dogwood tree, Cornus, but you can produce blue dye using the bark of the dogwood tree and a greenish-blue dye from the red fruit that is plentiful in the autumn and winter, often turning a brilliant scarlet.
The dye is extracted by boiling large quantities of the bark or fruit with water. It must be strained before dyeing fabric.
Hyacinth, as it is commonly known, or Hyacinthus, Asparagaceae, is a group of plants grown from bulbs in a range of colors including white, yellow, pink, purple, and blue. Native to the Middle East, the bulbs became a garden standard in most of the world when the bulbs were cultivated commercially in the Netherlands.
To create a blue dye, use the blue and purple blooms in large quantities boiled with water.
Indigo, Indigofera tinctoria, is a shrub or small tree found in many countries in southeastern Asia. The dye is derived from the leaves of the indigo plant that are red or purple. The leaves are usually divided into smaller leaflets. The small rose, purple, or white flowers are borne in spikes or clusters. The fruit is a pod, usually with a thin partition between the seeds.
Indigo plants were brought to the American colonies and were grown in the deep South for many years but never became the cash crop that many settlers expected because of the special techniques needed to extract and create dye powder for export. The crop was soon replaced by rice and cotton.
The leaves are boiled to extract a deep, true blue dye. Natural indigo powders can be purchased if the plant is not accessible.
Japanese Indigo, Polygonum tinctorium, is also called Dyer's Knotweed. It is an annual plant that is started from seed. It has a relatively short growing season and can produce enough growth for several dye batches each summer. Seed can be saved to grow it again the next year.
Creating a dye bath from Japanese Indigo takes many steps and the addition of household ammonia and sodium hydrosulfite. Learn how to make a great deep blue dye from Japanese Indigo at Sheep to Shawl website.
Oregon Grape, Mahonia aquifolium, is an evergreen shrub related to the barberry. It is not part of the grape family; however, it does produce clusters of blue/purple fruit that look like grapes.
The Oregon Grape is native to the northwestern United States but has been cultivated for use in the home garden nationwide except in tropical areas.
To extract the dye, gather the fruit when it turns blue and boil with water using an alum mordant. Strain the solution before using.
Saffron Crocus Petals
The stigmas of the saffron crocus, Crocus sativus, are worth their weight in gold, maybe even more. Saffron is a very expensive but prominent and treasured spice in many Asian cuisines.
It is the blue petals of the crocus flower that will produce a lovely blue/green dye. It will take many, many petals boiled with water to achieve the dye bath color you desire.
You can find iris blooming in every color of the rainbow. But to achieve a blue dye, you'll need the blue/purple iris blooms. Gather the blooms fresh or dried and use an alum mordant to achieve a blue dye when boiled with water.
Woad, Isatis tinctoria, also called Dyer's woad, is an herb that contains the same chemical in its leaves as true indigo and will produce a blue dye. The concentration of the chemical is not as strong as in true indigo but it will produce a beautiful blue.
Woad is native to Central Asia but is now found around the world. To some, it is a noxious weed, to others a cultivated crop for the extracted dye.
The steps for extracting the blue dye are a process similar to Japanese Indigo and the steps must be followed carefully.