How to Grow and Care for False Indigo

Jump to Section

You've seen the false indigo plant in gardens before, but you're not sure how to take care of it and make sure it comes back every year. 

Most plants are annual, which means they only last for one season. It can be frustrating when you put all that effort into planting something, and then it dies at the end of the year.

False indigo is a perennial, which means it will come back every year if you take care of it properly. Here are some tips on how to grow and care for your false indigo plant so you can enjoy its beauty every spring.

What is False Indigo?

False indigo, also known as Baptisia australis, is a perennial, flowering plant belonging to the Fabaceae or pea family. It has other common names, including blue false indigo and blue wild indigo, and blue, pea like flowers. False indigo is native to the southern prairies of North America.

False Indigo
Image credit: https://roundstoneseed.com/

It gets its name for originally being an affordable, wildflower alternative to true indigo. Much like true indigo plants, you can use its blue flowers to make blue dyes. Some common wild varieties produce different flower colors, including white indigo or Baptisia alba and yellow indigo or Baptisia sphaerocarpa, while the purple smoke cultivar produces purple flowers.

All types of false indigo are drought tolerant and make for impressive additions to cottage gardens and native plant gardens. Plant false indigo in a native plant garden to encourage activity by native pollinators.

Types of False Indigo

Purple Smoke False Indigo

The purple smoke variety of false indigo, Baptisia sphaerocarpa, is an ornamental plant with purple flowers. This species typically blooms in early spring or late winter and thrives in the U.S. It has purple eyes in the center of the blue flowers. So, if you’re looking to add some spring blooming flowers to your garden, go for this one.

Carolina Moonlight False Indigo

The Carolina Moonlight variety of false indigo, Baptisia australis, is distinguished by butter-yellow flowers on 18-inch long spikes that bloom for six weeks. This species blooms throughout spring and summer and is native to North America. The flowers on this plant typically appear before its leaves come out.

Twilite Prairieblues

This is one of the several in the prairieblue series developed by the Chicago Botanical Garden. It has bicolor flowers, purple with buttery yellow. Plants are three feet tall and wide.

Midnight Prairieblues

This complex hybrid of Baptisia tinctoria, Baptisia alba, and Baptisia australis. Its flower spikes are extremely long, deep violet-blue.

Solar Flare Prairieblues

This is a complex hybrid of Baptisia australis and Baptisia alba. Its flower color changes from buttercup yellow to warm, then plum as the flowers age.

How to Plant False Indigo

False indigo does best in USDA hardiness zones three to nine. At any time during the growing season, plant your false indigo plants by early spring to see them bloom from late spring to early summer.

When it comes to spacing, place them 3 to 4 feet apart, depending on their spread at maturity. Because false indigo plants can take years to reach their full size, don't be tempted to space them closely. Baptisias form a deep root system, making them difficult to move once they make themselves at home.

How to Care for False Indigo

False indigo doesn't require a lot of maintenance. The plant can sometimes flop over from the center of the clump outward, especially if you grow it in shady conditions that cause the plant to get leggy. You can use large hoop support to keep the plant upright in some situations.

How to Care for False Indigo
Image credit: https://www.thespruce.com/

If you fail to deadhead the flowers, you'll get attractive seed pods similar to pea pods, which turn dark and rattle in the breeze. You can prevent this by giving your false indigo a modest shearing after flowering. You'll also need to trim the stalks near the ground level as winter sets in or immediately in the spring before new growth begins.

Light

False indigo prefers full sun, although it can tolerate part shade. It's considered an understory plant—that is, a plant that requires partial shade—in the wild. But you'll get better garden performance if you give it plenty of sun. Flowering will be minimal in light shade, however. It will also get floppy without at least six hours of full sunlight daily. Full sun also prevents fungal diseases.

Soil Requirement

False indigo is incredibly resilient and will tolerate poor soil. For the best result, plant it in a well draining soil with a slightly acidic pH level. It will also tolerate dry soils once it's well established. It's also not particular about soil pH, but as mentioned earlier, it does best in soil that is slightly acidic to neutral. So, make sure you know how to test soil pH so that you don’t hurt your plant.

Water Requirement

These perennial plants are extremely drought tolerant and low maintenance. Water false indigo during the first few growing seasons until it becomes well established. It's best to water it regularly rather than in longer infrequent sessions. Don't keep it soggy, however; this can cause root rot.

Instead, provide enough water so that the soil is moist but not soaked, and let the top two inches of the soil dry out between watering. This is a native wildflower, and in most regions, it does fine with whatever rainfall nature provides.

Temperature and Humidity Requirement

If you let them, false indigo plants are likely to become naturalized in your garden. However, if you want to keep it under control, it should be planted in full sun or partial shade. False indigo plants will do best in average temperatures of 65°F (18°C) — they won't tolerate frost or heat.

The false indigo plant does equally well in dry and humid climates, provided it gets adequate soil moisture.

Fertilizer

Because they're legumes, Baptisias supply their fertilizer through the nitrogen-fixing bacteria on their roots. This makes feeding not necessary and can even be counterproductive. Excessive fertilizing can cause the plant to get leggy and flop over. 

Pruning False Indigo

False indigo doesn't require pruning. However, the only pruning required is to prune off dead seed pods as they can attract weevils. This is required in late fall or early winter, or the spring before new growth begins.

Pruning False Indigo
Image credit: https://img.washingtonpost.com/

And because this plant takes a shrub-like appearance, you can also shape it by pruning, which should be done immediately after its flowering period is over. Pruning may also be required to improve air circulation.

Propagating False Indigo

Propagating false indigo by seed requires fresh seeds for germination, and new plants can take several years to produce flowers. For faster results, propagate your plants using stem cuttings.

In early spring, before the growing season begins, take a stem cutting that's long enough to bury at least one set of buds in humid, loose soil and at least one set of leaf buds near the bottom of the cutting. Keep the stem cutting moist, and a new root system should take hold within a few weeks.

Overwintering

There is no required winterizing routine for these plants. Many people cut the stems to ground level as winter approaches, but you can omit this if you want to leave the seed pods in place for winter interest. And in borderline zones where winters are damp and above freezing, clearing the ground of plant debris is a good idea to keep the soil from being too soggy and possibly causing root rot.

Common Pests and Diseases

In overly damp conditions, false indigo may develop powdery mildew or rust. To prevent this, avoid overwatering your Baptisia plants and ensure proper air circulation. Weevils also have been known to eat Baptisia seeds, but this is a problem only if you're saving the seeds to plant.

False Indigo Pests and Diseases
Image credit: https://www.gardeningknowhow.com/

Other problems include flopping plants and crown rot. When the plant is growing in shady conditions, the stems may grow leggy in their effort to reach the sun, causing the stems to flop over, usually from the center outward. Pruning is inevitable to increase the amount of sun and prevent this flopping.

Large segmented hoop support can also help keep the stems upright. Hard pruning after flowering is complete can also keep the plants shorter and bushier, eliminating the flopping problem. False indigo may also develop root rot in water that's saturated for periods.

Soil amendments around the plant can improve the soil's drainage. Some earthmoving to redirect water can also help to eliminate puddling that causes root rot.

How to Get False Indigo Bloom

False indigo produces flower spikes up to 5 feet tall, but it won't bloom without pollen. Insects are the best pollinators for false indigo. A plant growing in shady conditions may experience reduced blooming, so prune out nearby trees and shrubs that shade the plant to improve its blooming.

Flowering can also be compromised if you prune too early before developing the flower buds. If you want to prune the plant, make sure you wait until summer when the flowering is done.

FAQs on How to Grow and Care for False Indigo

How can you use false indigo in the landscape?

False indigo has a dramatic look, so plant it in prominent areas of the landscape. It is most dramatic when planted as a massed group or along fences and walls. If you want to use false indigo as an ornamental ground cover plant, space plants about 12 inches apart.

How did false indigo get its name?

False indigo is a native wildflower, and its common name is traced to early European settlers and traders who paid Native Americans to produce indigo dye. To the settlers, these plants looked very similar to true indigo, native to Africa and Asia, but produced inferior blue dye.

Final Thought on How to Grow and Care for False Indigo

As you can see, false indigo is a versatile and hardy plant that can be employed in a variety of ways. As a ground cover, this low-maintenance perennial will brighten up your yard with its beautiful blue color.

 

Kristina Perrin

Kristina Perrin

Kristina is a stay-at-home-mom and an expert chef. When she's not cooking or experimenting with new recipes, you can find her writing about her favorite kitchen appliances on Kitchen Infinity blog.

Related Articles

Download Free Chart Now!

Your email will be used only to confirm your request and to provide free kitchen information. By submitting your info on this form, you are agreeing to be contacted regarding your service request by means of email. This is no obligation form and doesn’t require you to purchase any service.

norton_black
comodo_black