How to Grow Isatis Plants

Gardener's HQ Guide to Growing Woad and Glastum in your Garden

Isatis is a genus of plants that are grown as hardy bulbs in the garden.

Isatis blooms in the summer with small yellow panicles and may reach a height of 30 to 90 cm in height.

Some of the common names for Isatis are Woad and Dyer's woad.

It has been traditionally used to produce dye and paint.

Isatis tinctoria
Isatis tinctoria - Dyer's Woad by Matt Lavin.

Woad
Woad by peganum.

Isatis Growing and Care Guide

Common Names: Woad, Dyer’s Woad, Asp of Jerusalem, Glastum.
Life Cycle: Hardy biennial.
Height: 12 to 36 inches (30 to 90 cm).
Native: Mediterranean, Western and Central Asia.
Growing Region: Zones 3 to 10.
Flowers: Summer.
Flower Details: Yellow. Small. Umbels.
Foliage: Elliptic.
Sow Outside: Cover seed. Late summer. Spacing 6 to 12 inches (15 to 30 cm).
Sow Inside: Germination time: two weeks to two months. Temperature: 50°F (10°C). Seven or eight weeks in advance. Transplant outdoors before the last frost.
Requirements and care: Full sunlight or partial shade. Good drainage. Rich soil. Propagate: Self seeds.
Miscellaneous: Was used by the Celts to produce blue war paint. Considered an invasive weed in many areas. Used in traditional Chinese medicine in the treatment of the flu, measles and scarlet fever, amongst others.

How to Grow Woad and other Isatis Plants in the Garden

Woad should be grown outdoors from seeds. The Woad seeds should be sown out in the latter part of summer and lightly covered. It can take from two to seven weeks for woad to germinate.

They should be planted in a sunny or partially shaded part of the garden into a rich, moist soil that has good drainage. Once the seedlings have emerged thin them out so that they are about 20 to 30 cm apart.