Blue False Indigo: How to Plant, Grow, and Care For Baptisia Australis
Are you looking to grow Blue False Indigo in your garden? Beginner gardeners or those wanting a low-maintenance, water-wise plant to add to their landscape will be satisfied with this native perennial. Gardening expert Madison Moulton takes a look at this popular plant, covering absolutely everything you need to know from planting to cutting the flowers in spring.
Native plants often provide plenty of rewards for very little effort, whether that be in their stunning flowers, vigorous growth, or glossy foliage. But very few plants provide as much reward for as little effort as Blue False Indigo – Baptisia australis.
In late spring, this plant shoots up gorgeous blue flowers reminiscent of other members of the pea plant family. But that’s not all there is to love about False Indigo. The glossy green leaves stand tall in garden beds, maintaining interest for the rest of the year out of the short flowering season.
The blooms are pollinator magnets and draw a range of good bugs to your garden in spring and summer. And, to top it all off, they have almost no problems with pests and diseases. Take a look at these growing and planting tips for everything you need to know about keeping your Blue False Indigo thriving in your garden.
Blue False Indigo Plant Overview
Plant Type Perennial
Species Baptisia australis
Alternative Names Blue Wild Indigo, False Indigo
Hardiness Zone USDA 3-9
Native Area Southeastern USA
Exposure Full Sun
Maturity Date 1-2 Years
Plant Spacing 3-4 feet
Height 4 feet
Watering Requirements Low
Heat Tolerance Moderate
Diseases Powdery Mildew, Leaf Spot
Soil Type Well-draining
Plant With Salvias, Lavender
Don’t Plant With Plants That Require Regular Watering
Native to North America and commonly found in the central or eastern parts of the United States, Blue False Indigo was used by Native Americans for hundreds of years.
It was primarily used as a blue dye. Strong pigments were extracted from the plant and used to color different materials. The long taproots were also harvested to make natural medicines to treat pain and nausea, and the hardened seed pods typical of the legume family were believed to be used as children’s rattles.
British settlers took notice of the Native American’s use of Baptisia as a blue dye. At the time, indigo pigments from the plant Indigofera tinctoria were incredibly popular. This plant originated in the West Indies and was shipped around the world in the 18th century. However, demand far exceeded supply, and the settlers began using Baptisia as a replacement.
Although the color was not as intense or vibrant as true Indigo, it did provide the blue hue in fashion in the 1700s. It became an essential crop and was even exported to other parts of the world until farmers began growing true Indigo in North American territory.
Its time as a global economically important crop may have been short-lived, but the plant’s popularity has not waned. Instead, it is now valued for its ornamental qualities and ability to grow well in a wide range of conditions with little to no maintenance.
Wild Baptisia australis can be found in the Midwest of the United States today. They are usually situated around woodlands or along streams and in meadows.
However, this native plant is not restricted to the wilderness, nor its native habitat. False Indigo is a common garden plant in the US, found in nurseries across the country. It is one of only a few native blue flowers that have the true blue color not often seen in nature. It is also incredibly easy to grow and establishes itself well in most parts of the United States.
Baptisia australis has also been introduced to other parts of the world and can be found growing in many European gardens. It has even won the prestigious Royal Horticultural Society’s Award Of Garden Merit, indicating its appreciation on continents far from its native area. It also won the award for Perennial Plant of the Year in 2010, awarded by the Perennial Plant Association. This is a big award for this popular blue perennial flower. Essentially, there are few places around the world where this plant is not beloved.
Baptisia is most often propagated from seed, but can also be propagated from cuttings or by division. Seed germination rates are not particularly high, and propagating from cuttings, although requiring more equipment, usually produces more reliable results. Propagating by division is only recommended after the plant has been growing for a few years and should only be done when absolutely necessary, as the long taproots do not like to be disturbed.
Propagating From Seed
At the end of the flowering season, around early to mid-summer, you should see seed pods starting to form and harden. Once they have turned brown to black, they should be ready to twist off the plant. To release the seeds, break open the hard outer shell and you should see a few seeds inside the pod.
For the highest chance of germination, it’s best to plant the seeds immediately after harvesting. They can be saved and planted later, but they become less viable with time. Inspect each seed for small holes before use. Weevils often break into the pods and burrow into the seeds, making them completely unusable.
As the seeds have a hard outer coating, there are several ways to prepare them before planting. Some gardeners use one method, others combine two or more, but some form of preparation will greatly increase your chances of success.
The first preparation method is stratification. This is usually only done when not using fresh seeds and involves leaving the seeds in the refrigerator for about six weeks before use to trigger germination.
The next step is scarification, done with fresh and older seeds. This process involves wearing down the hard outer shell with fine-grit sandpaper or making a small cut with a knife to allow moisture to penetrate the seed. After scaring the outside, you can also soak the seeds in hot water for 24 hours prior to planting to increase germination rates.
Sow the seeds into plug trays filled with a seed germinating medium like coconut coir. Plant two to three seeds per plug and thin out the strongest sprouts later on. Sow the seed on top of the soil and press down gently to ensure contact but do not cover until the seed begins to open.
Germination should take a couple of weeks. However, it’s best to leave your seedlings in the tray for at least two months. This allows them to establish a strong root system before planting to give them the best chance of success. Plant your seedlings in the garden in mid to late spring when all danger of frost has passed.
Plants grown from seed take several years to mature and flower. Once transplanted, you may only see your first flower after two or three years, sometimes four. If you’re looking for faster results, propagating from cuttings is your answer.
Propagating From Cuttings
Cuttings are best removed in early spring when the new growth is still soft and green. Woody cuttings are far more difficult to root and have low success rates.
Remove a section of a branch a minimum of four inches long, just below a set of leaves. The bottom section of your cutting should still be softwood. If there are any woody areas, simply remove them with your pruning shears.
Remove the leaves from the bottom half of the cutting. Dip the bottom end into some water and a rooting hormone powder before planting. This stimulates root growth and prevents any issues with fungal diseases. Baptisia can struggle to root, depending on the conditions, so rooting hormone will greatly improve your chances of success.
Fill a pot with a well-draining potting medium. Some options include coconut coir, loose potting soil, perlite, and vermiculite. Moisten the mixture before planting by watering and letting all the excess drain from the drainage holes.
Make a small hole in the mixture using a skewer and bury the cutting halfway, ensuring the remaining leaves stay above the soil. Cover the pot with a clear plastic bag, such as a sandwich bag, to build up humidity and retain moisture.
Leave the pot in a warm spot away from direct sunlight to encourage root growth. Continue to mist the soil every few days to keep it moist. New visible growth indicates that roots have grown below the soil. The cuttings should be ready to move into larger individual pots or into the garden in just under two months.
Propagating by Division
Division is not recommended for these plants as the long taproots do not like being disturbed. The plant can easily suffer from shock if divided, and may not recover or retain its previous level of growth. However, if you’re looking to keep your garden tidy, division may sometimes be necessary. Every 4-5 years, the plants may become crowded and will require splitting to control their growth.
To ensure the least damage, dig up the plant in early spring as new growth starts to emerge. Loosen the soil around the plant and dig deep to remove as much of the roots as possible. The deeper you dig, the higher your chances of success, as the roots can travel several feet down into the soil.
Shake the soil off the plants so the roots are visible. Mature plants will need to be separated with a knife or saw to split into separate plants. Try to disturb the roots as little as possible and ensure each division has the same number of roots left over.
Once divided, replant immediately to stop the roots from drying out. Once planted, water thoroughly and keep well-watered for several weeks to prevent stress. If the plants appear to struggle to establish, they may need to be removed from the garden.
The risk of losing your entire plant when dividing is high. Stick to other propagation methods and only divide your plant if there is no other alternative.
Transplant seedlings or nursery-grown container plants in early spring once the weather has warmed. To give your plants the strongest start, there should be no imminent frost to prevent early damage and transplant shock.
To prepare the site for planting, loosen the soil a few feet down and remove any weeds or debris in the area. These plants will establish quickly if the roots are given the room to grow freely downwards, and any compacted soil below the planting hole will prevent that growth.
Mature plants will grow several feet tall and up to six feet wide. They, therefore, need plenty of space to spread when planting multiple plants. Space each transplant around four feet apart for the best results. It may look sparse at first, but the foliage will fill out in no time.
After planting, water slowly and deeply to penetrate the lower levels of the soil. Keep the soil well-watered until the plant is established.
Once planted, do not move the plant or disturb the deep root system. Any disturbance will result in stress and may kill the plant. Plan your beds in advance to ensure you don’t need to do any digging in the area soon after planting.
How to Grow
When entering the growth stage, it’s important to ensure that you meet the physical needs of your plant. You’ll want to make sure you have proper light, water, soil, climate, and fertilization to maximize how your flowerbeds will grow. Let’s take a look at what your Baptisia will need in each of these categories to grow properly.
Baptisia australis requires a sunny position for most of the day to produce flowers. The minimum recommended amount is six hours, but they will benefit from more.
As these plants are very adaptive, they can also grow in partial shade and may throw up a few flowers. However, rather than being dense and bushy, the foliage will be sparse and the stems may become leggy. In partial sun positions, you can stake the plant to keep it upright, but it’s best left in a full sun position if you can manage it.
While the plant is establishing its deep, extensive root system, it will require regular watering. You can water these plants about the same amount as you water other perennials in your garden for the first year of growth.
Once the roots have grown deeper into the soil, you can majorly reduce your watering schedule. These deep roots several feet down can access water in the soil that does not evaporate from sun exposure, keeping the plant going even when conditions appear dry. These long-lived perennials will remain drought-tolerant and can often survive on rainwater alone in the right regions.
Like many other native plants, Baptisia is not fussy about soil. It can grow in very poor quality soils with little nutrients, provided they are well-draining. As the roots are very sensitive, they do not respond well to overwatering and require well-draining soil to prevent root rot.
Loam or sandy soil is ideal, with a slightly acidic to neutral pH. Clay soil will need to be amended with compost and sand to create the right consistency needed for optimal growth. These amendments should reach the lower parts of the soil too, as this is where most of the roots will reach.
Climate and Temperature
Baptisia can be grown in USDA Zones 3-9, preferring milder weather over extreme temperatures.
It prefers drier weather to rainy regions. Excessive rain can result in too much moisture in the soil – not ideal conditions for drought-tolerant plants. Wet, humid weather also encourages the growth of fungal diseases which can affect these plants if not spaced properly or grown in the shade.
The foliage will begin to turn black once frost hits and will die back completely by winter. Damaged foliage will change color and fall over, becoming unsightly. To keep your landscape tidy, you can cut back the damaged foliage, but the plant will go through its natural life cycles without this trim.
These native perennials require no additional fertilizer for successful growth. As legumes, these plants are nitrogen fixers that manage soil fertility on their own. They are also able to grow in poor-quality soils with little nutrients and don’t require any extra fertilizing.
If your plant does not appear to be growing as successfully as in previous years, or you want to give them a boost for the best performance, you can apply a diluted general-purpose fertilizer once in the early spring. Alternatively, apply some fertile compost around the soil (without mixing it in to disturb the roots) and this should provide enough nutrients to sustain the plant for the year.
Care & Maintenance
The major benefit of these plants is that they require almost no maintenance. How involved you are is totally up to you.
If you don’t like the look of the browning foliage in early winter, you can prune the plant back. Alternatively, you can leave it to its own devices and it will die back naturally.
If you don’t want seed pods to remain on the plant, you can cut back the stalks after flowering or once the pods have grown. However, the black pods do have a wonderful ornamental quality, providing contrast amongst the blue and rich green. At the end of the day, what you do with them is your choice.
Mulching is not a necessity, and staking is only required if growing plants in the shade as they will not have enough energy to keep themselves upright.
In other words, Baptisia australis is one of the most low-maintenance plants around.
Horticulturalists have developed several interesting cultivars of Baptisia, specially created for their ornamental value.
One of the oldest, and the most common, hybrid is ‘Purple Smoke’. Its dense, bushy growth is topped with deep violet blooms and a dark purple eye in the center. They look similar to the classic Baptisia, with a bit of a twist.
For something completely different, try ‘Solar Flare’. Evident in the name, this hybrid has fiery orange flowers that fade into a bright yellow toward the top of the flower spike. Far from the calming blue effect of Baptisia australis, ‘Solar Flare’ adds an energetic pop of color to any landscape.
‘Starlite Prairieblues’ offers a more delicate look, with soft purple-blue flowers dotted with touches of white. ‘Twilite Prairieblues’ falls on the opposite end of the tonal spectrum, with deep purple flowers and spots of yellow that look like stars in a dark night sky.
Harder to find but worth the purchase, if you do come across one, is ‘Midnight’. This hybrid has dark blue, almost navy blooms with touches of purple. The dark blue color, unlike any other flowers on the market, adds an essential wow factor to your beds.
Pests and Diseases
When grown in the right conditions, these plants are virtually pest and disease-free.
If planted too close together or in very wet, humid conditions, a few common garden fungal diseases may appear. Powdery mildew is the most common, but leaf spot and rust are also concerns.
To prevent issues with fungal diseases, plant in a full sun spot to allow any water that lands on the leaves and stems to evaporate early in the morning. Ensure the plants are not overcrowded and prune overly dense growth to improve airflow.
As for pests, the only problem you may have to contend with is weevils. They are common across the US, burrowing into the seed pods and destroying any propagation prospects. Check the seeds for small holes before planting and never bring infected seed pods indoors.
In the garden, Blue False Indigo has a wide range of uses.
Reaching a height of about four feet, it’s great for framing shorter perennials or annuals in a flower bed. The tall stems form a dense shrub for most of the year when the plant is not in bloom. The shiny, light green foliage is a great bright contrast to other leafy deep green plants.
When it is in bloom for a few short weeks in late spring to early summer, it will attract a wide range of pollinators – particularly butterflies. Many butterfly species adore Blue False Indigo, adding even more color to your garden through the season.
Its drought tolerance makes it ideal for water-wise gardens. Plant amongst other drought-tolerant plants to limit water usage and save on your water bill without compromising your design. Lavender is a great option, as the dusty purple flowers complement the False Indigo flowers wonderfully.
The blooms are also great cut flower specimens. They last quite long in a vase and have a similar look to lupines. Use them as a replacement for lupines in late spring when the flowers are not yet available, swopping them as they exchange blooming times.
The dried seed pods also offer ornamental value and are often used in dried flower bouquets. They offer a strong contrast to the softer types of flowers and add a sensory element in the form of sound when swaying in the wind.
Frequently Asked Questions
Is false indigo toxic to dogs?
Baptisia is mild to moderately toxic to pets, although the intensity of the toxicity is not well-known for specific animals. Ingestion may result in nausea and possibly vomiting. It’s best to keep this plant away from all pets to stay on the safe side.
Is Baptisia deer resistant?
Deer are not fans of this plant, and should leave the ones in your garden alone. Although some are known to test the waters, they find the taste unpleasant and will usually stay far away from this plant.
Is false indigo invasive?
Baptisia australis is not invasive in the US and is natively found across the Midwest. The common name may be confused for a different invasive plant, False Indigo Bush (Amorpha fruticose) which is a weed with long purple flowers and is invasive in some regions.
What can I do with false indigo seed pods?
There are many uses for the attractive seed pods of this perennial plant. They add an interesting color contrast to the bright green leaves and blue flowers if left on the plant. If there are many seed pods, they may weigh the plant down, but a few left on the plant make for an interesting display in your garden beds.
You can also use them to grow more plants. Each pod contains several seeds that, with a bit of preparation, should grow into healthy false indigo plants within a few years. Soak the seeds in water and pierce the hard coating with a knife or sandpaper before planting for the highest chance of success.
When the stalks are removed, they also look great in dried flower bouquets. Not as short-lived as their fresh counterparts, dried flower bouquets are incredibly trendy and suit the natural interior décor trends popular at the moment. Add some home-dried flowers from your garden to complete the look and place in a vase.
Can false indigo be pruned?
If you like to keep your garden meticulously neat, this plant can be pruned. This is best done once frost has killed the foliage of the plant or some time in winter before new spring growth emerges. You can also cut back any dense foliage to promote airflow. However, these plants don’t get pruned in the wild and will grow well without an extra trim.
Can you divide Baptisia?
You can divide Baptisia, but it is not recommended. This plant does not like to be moved and will struggle to establish again if the long roots are disturbed. Only divide the plant if absolutely necessary – as in if growth becomes uncontrollable. If you’re simply looking to propagate and grow more false indigo plants, growing from seed or taking cuttings is a far safer option.
A native beauty, Blue False Indigo is a stunning addition to any garden inside and outside the US. These plants need little to no attention and add value to your garden each year without any trouble. If you’re happy to have a wilder look, they can be left alone for most of the year, with rain and sunshine taking care of all its needs. The only time you will likely interact with this plant is to snip its stunning blooms and bring them indoors for a homemade cut flower display.