Blue wild indigo is a wildflower native to the Eastern United States. The flowers bloom throughout the spring and resemble pea blossoms, however, they are a lovely blue-purple. The plant juice can actually be used to make a purple dye if true indigo is not available.
| Common name | Blue False Indigo, Blue Wild Indigo, False Indigo, Wild Indigo |
| Botanical name | Baptisia australis |
| Family | Fabaceae |
| Species | australis |
| Origin | Central & Eastern U.S.A |
| Life cycle | Perennial |
| Plant type | Native Plant |
| Hardiness zone | 3, 4, 5, 6, 7, 8, 9 |
| Sunlight | Full Sun |
| Maintenance | Low |
| Soil condition | Clay |
| Soil ph | Acid |
| Drainage | Well-Drained |
| Spacing | 12 in. – 3 ft. |
| Harvest time | Winter |
| Flowering period | Spring |
| Height | 3 ft. – 4 ft. |
| Width | 3 ft. – 4 ft. |
| Flower color | Blue |
| Leaf color | Blue |
| Fruit color | Black |
| Fruit type | Legume |
| Fruit benefit | Good Dried |
| Flower benefit | Long Bloom Season |
| Garden style | Butterfly Garden |
| Uses | Houseplants |
I. Appearance and Characteristics
Baptisia australis, commonly known as blue wild indigo or blue false indigo, is a flowering plant in the family Fabaceae (legumes). It is a perennial herb native to much of central and eastern North America and is particularly common in the Midwest, but it has also been introduced well beyond its natural range. Naturally it can be found growing wild at the borders of woods, along streams or in open meadows. It often has difficulty seeding itself in its native areas due to parasitic weevils that enter the seed pods, making the number of viable seeds very low.
Baptisia australis is an herbaceous perennial that reproduces both sexually and asexually by means of its spreading rhizomes. The plant is erect and emerges from the rhizomatic network. The roots themselves are branched and deep, which helps the plant withstand periods of drought. When dug up they are woody and black in color and show tubercles, wart-like projections found on the roots. The plant branches extensively about halfway up. The stems are stoured and glabrous, or hairless. Broken stems secrete a sap that turns dark blue on contact with the air.
The plant may attain a height of 1 to 1.5 meters, and a width of 0.6 to 1 meter. The gray-green trifoliate leaves are arranged alternately, and are further divided into clover-like leaflets that are ovate in shape, or wider towards the apex.
Flower spikes appear in early summer. Emerging at the pinnacle are short, upright terminal racemes with pea-like flowers that vary in color from light blue to deep violet. The flowers, which bloom from spring to summer depending on the region, are bisexual and are roughly 2.5 cm (0.98 in) long.
The fruit is a bluish black inflated and hardened pod that ranges from 2.5 to 7.5 cm (0.98 to 2.95 in) in length by 1.25 to 2.5 cm (0.49 to 0.98 in). They are oblong in shape and are sharply tipped at the apex. At maturity they will contain many loose seeds within. The seeds are yellowish brown, kidney shaped and about 2 mm (0.079 in) in size.
The leaves emerge about one month before flowering and are shed approximately one month after the pods form. Once the seeds are fully mature, the stems turn a silverish gray and break off from the roots. The pods stay attached and are blown with the stems to another location.
Young shoots of the plant have been mistaken for asparagus, which resulted in poisoning. The seeds may be toxic, especially for children.
Baptisia australis grows best in lime-free, well-drained stony soil in full sun to part shade. Like other members of the genus, it has a very deep taproot, which makes it quite difficult to move once planted. It thrives in full sun and requires water only in times of low rainfall. One slightly negative feature is that the leaves tend to drop early in the fall, but this may be avoided by cutting the dead stems as they die back. It is hardy in USDA zones 3 through 8. It is commonly employed as a border plant in gardens.
II. How to Grow and Care
Sunlight
False Indigo will get floppy without at least six hours of full sunlight daily. Full sun also prevents fungal diseases.
Temperature and Humidity
False indigo will thrive in the garden in the conditions throughout its hardiness range, zones 3 to 9. It does equally well in dry and humid climates, provided it gets adequate soil moisture.
Watering
Water your false indigo well the first year to enable it to become established. Water deeply at least once a week. If the weather is especially dry or hot, water two or three times a week to help your young plant keep its roots protected. While it prefers consistent moisture, it forms an almost solid taproot, which helps it become highly drought tolerant over time.
Soil
False indigo prefers moderately well-draining soils, but it will tolerate dry soils once it is well established. It is not particular about soil pH but does best in soil that is slightly acidic to neutral.
Fertilizing
Baptisias succeed even in areas of very low fertility, being adapted to the American prairie. If desired, choose a balanced fertilizer in spring, repeating monthly in summer. You can simply use a slow-release type in spring.
Planting Instructions
Baptisias thrive in sites with full sun in neutral to slightly acidic, well-drained soil on the dry side. Shadier locations can cause floppy, weak growth. Rich soil is ideal, but they will tolerate poor soil as well. Dig a hole twice as wide as the root ball. Allow space for the clump to grow up to four feet wide, and give it room between other plants to promote air circulation. Small plants may take two years to bloom.
Pruning
No pruning is really necessary for false indigo, as all growth renews from the base in spring. You can cut back the plant by one-third to shape it after blooming. Removing the spent flowers (deadheading) is also optional, but then you won’t enjoy the interesting seed heads rattling in the fall breeze.
Propagation
Because false indigo plants have long taproots, they are difficult to divide; however, they do grow well from stem cuttings. Here’s how to do it:
- In April to early May, use a sharp pruner to take stem cuttings about 6 inches long, containing at least two sets of leaves and at least one set of leaf buds near the bottom of the cutting.
- Dip the end of the cutting in rooting hormone and plant it in a small pot filled with standard potting mix. Moisten the potting mix.
- Place the pot and cutting in a plastic bag or another form of plastic covering. Keep the pot in a bright, uniformly warm location, monitoring it frequently and lightly watering it if the potting mix dries out. In about eight weeks, the cutting should be rooted.
- When the cutting has rooted, remove the plastic and continue growing the new plant until it is large enough to plant into the garden.
How to Grow from Seed
Growing false indigo from seed is possible, though not recommended. False indigo seeds have a hard outer coating, and some type of scarification will improve germination. Soaking them in hot water for at least eight hours prior to scarifying them would be even better, although some gardeners have luck simply planting the seeds in the fall and allowing the winter weather to soften the seed coat.
But growing from seed is a lengthy process, as the plants will take three to four years before developing the size required for meaningful blooms. Thus, most people propagate these plants through stem cuttings.
Overwintering
There is almost no required winterizing routine for these plants. Many people cut off the stems to ground level as winter approaches, but even this can be omitted 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.
Pests and Diseases
Common Pests & Plant Diseases
Fungus diseases such as leaf spot, powdery mildew, and rust can occur if grown in crowded, damp conditions. Be sure to provide good air circulation around your Baptisia plants.
Weevils have been known to eat Baptisia seeds, but this is a problem only if you are saving the seeds to plant.
Common Problems With False Indigo
Few plants are more trouble-free than false indigo. But rarely, there are a couple of issues you may need to address.
Flopping Plants
When the plant is growing in shady conditions, the stems may grow leggy in their effort to reach the sun, causing the stems to eventually flop over, usually from the center outward. Sometimes, pruning of surrounding trees can increase the amount of sun and prevent this flopping. Or, a large segmented hoop support can help keep the stems upright. Relatively hard pruning after flowering is complete can also keep the plants shorter and bushier, eliminating the flopping problem.
Crown Rot
In soils that are too water-saturated for long periods, false indigo may develop root rot that causes the plant to turn mushy and collapse. Soil amendments around the plant can improve the soil’s drainage. Some earthmoving to redirect water can also help eliminate puddling that causes root rot. Badly affected plants are not salvageable and will need to be removed.
III. Uses and Benefits
- Ornamental uses
Blue wild indigo is a common addition to gardens: it is easy to grow, has very attractively-shaped foliage, and sports bright blue flowers. Informal and cottage gardens are a particularly good setting for groups of this loosely-packed perennial, especially next to different cultivars of Bluestar and Goldenrod.
- Other uses
Several Native American tribes have made use of the plant for a variety of purposes. The Cherokees traditionally use it as a source of blue dye, a practice later copied by European settlers. They have also used the roots in teas as a purgative or to treat tooth aches and nausea, while the Osage make an eyewash with the plant. Ripened seed pods have been used for children’s rattles.
Find Where to Buy the Best Blue False Indigo (Baptisia australis)
[content-egg-block template=offers_logo_shipping cols_order=3,2,1,5,4 hide=badge visible=number border_color=info limit=8]