Wild Blue Indigo is not a true indigo, but it gets its name from the fact that it was often used as a substitute to make blue dye. This is great plant for dry and sunny sites, and the purple/blue flowers look beautiful when paired with other white and yellow spring-blooming plants. It is slow growing and low maintenance, and also sports large, interesting seed pods that rattle and persist throughout winter, providing multiple seasons of interest.

Care requirements:

Light requirements: Full sun-part shade

Water requirements: Low-Medium

Soil requirements: Dry-Medium, well-drained

Bloom time: May-June

Bloom color: Purple

Height: 3-4 feet

Width: 3-4 feet

USDA Zone: 3-9

Larval host: Orange Sulphur, Clouded Sulphur, Frosted Elfin, Eastern Tailed Blue, Hoary Edge, Wild Indigo Duskywing butterfly

Other notes: Wild Blue Indigo flowers best in full sun but will also tolerate part shade. In part shade though, it may require staking. It has a deep extensive root system that should not be disturbed once established. It tolerates drought and poor soils but does not tolerate being planted near black walnut trees well (juglone). This plant is long-lived; if grown from seed it will take 3-4 years before it blooms for the first time.

Emily’s notes: While multiple reports suggested Wild Blue Indigo to have a low germination rate, I found it rather easy to germinate. The seeds require scarification and stratification, but I also had success with just scarifying the seeds and soaking for 24 hours before planting. While it was easy to get seeds to germinate, I did have a lot of problems getting the seeds to grow into actual plants. The seed coat is so tough that often the seedlings would get stuck when trying to emerge and the cotyledons (baby leaves) would break off! These seeds are also relatively small making them somewhat difficult to scarify.

Do you have Wild Blue Indigo growing in your garden? Do you have any tips or tricks for growing it you would like to share? Do you know of any Southeastern nurseries that regularly stock it? Let us know in the comments!