Baptisia - False Indigo

3/27/2024 9:21 am

 

 

 Baptisia 'Ivory Towers' - Photo courtesy of Plant Delights Nursery

 

 

My dear friend John asked me to write about the top ten perennials. I agreed, as long as he didn't ask me to write about daylilies (also known as "deer nummies" in my neck of the woods). Instead, I chose to write about another highly hybridized perennial, which I actually get to see in bloom for more than a millisecond: Baptisia, commonly known as False Indigo.

 

This will be an unusually picture heavy article because -- as with hosta -- the distinctions between cultivars is better seen than described. We may get to learn even more about Baptisia when Richard Hawke comes to talk to us during our February 2025 Symposium!

 

Baptisia Basics

 

Baptisia is a low maintenance plant in the pea family that grows in Zones 4-9. The give away to the amateur botanist is the three part round leaves. Growing in a clump, anywhere from 2 1/2 to 5' feet tall and equally wide or even wider, Baptisia is a reliable garden performer which asks little of the gardener. Once established, it is drought tolerant. It can also withstand periodic flooding. It takes full sun and hot weather, so that's in its favor too. Six hours of sun is recommended for best bloom. 

 

In early spring, the stems of Baptisia shoot up from the ground fairly quickly, resembling asparagus spears. The flowers, which are the typical pea butterfly shape, arrive in early to middle spring, with as much as a month's variation among species and cultivars. After blooming, Baptisia develops seedpods that rattle in the breeze. Some people like these; others don't (John!). You can always remove the seedpods if they are not your "cuppa". The long lasting foliage is a good background even without the rattles. The seedpods are valued in flower arranging. Otherwise, you generally would not cut back Baptisia stems until late winter or early spring before the shoots peek up from the ground.

 

Baptisia typically are pest free. Alkaloids in Baptisia are toxic to many insects, although one year kudzu bugs decimated a young Baptisia not yet dug into the ground, killing it. The kudzu bugs must have found more delicious pea family foliage since then and have not been a problem again. Increasingly, however, the Genista Broom Moth caterpillar (which can appear in yellow to more orange shades) is becoming a problem for Baptisia. But don't worry. Even if they munch your Baptisia to the ground, unless it is a very young plant, it will arise like the phoenix from the ashes next year. And the good news is that they don't appear until after Baptisia finishes blooming.

 

 

Otherwise, Baptisia is said to be a host plant to caterpillars who dine broadly on the pea family like Orange Sulphur, Clouded Sulphur, Frosted Elfin, Eastern Tailed Blue, Hoary Edge, and Wild Indigo Duskywing caterpillars. That said, I've rarely seen much caterpillar damage to these plants so in my garden, so perhaps it may not be their first choice in the expansive pea family of plants. Another plus: early bumblebees feed off its nectar of Baptisia.

 

Baptisia are very long-lived perennials, so you will likely have them until you make a choice not to. Remember that when you position them in your garden. They have a reputation for not transplanting well, although that may be more about the difficulty of digging up mature specimens with deep, brittle roots and timing of transplanting. Spring is recommended as the best time to transplant Baptisia, giving plants a long season to recover.

 

 

Species and Cultivars

 

Twenty years ago, you mostly found only blue Baptisia at nurseries. Later the other naturally occurring colors, white and yellow, began to be sold. Some interesting naturally hybridized forms were also found. Then the hybridizers got involved and so began the "Wild West" of Baptisia breeding. Hybridizers initially worked on improving colors, making the plants more floriferous, and straightening out the bloom stalks which had a tendency to become pendulous (or as Tony Avent describes them "lazy"). When they had that figured out, they moved on to creating some wild color combinations and even eking out a pink form. Foliage and stem variations are another area of recent improvement. 

 

The Blues

 

Baptisia australis is the oldest nursery sold variety. Native to the Mid Atlantic and many eastern states, it features tall plumes of blue to indigo flowers that can get floppy with age. Baptisia australis grows 24-30" high by 18-24" wide generally, but clumps of 4' wide are not unusual. This was named Perennial Plant of the Year in 2010. A lot sure has happened since!

 

Baptisia 'Purple Smoke' was an early hybrid and a definite improvement in erectness with flowers borne on charcoal stems. The flowers are dusky purple and well, you get the smoke like impact from the picture below.  

 

Photo courtesy of Mt. Cuba

 

Plant Delights later introduced Baptisia 'Cloud Nine,' which looks to my eye like B. australis on steroids. Growing to 4' high, it can go over 5' wide. As you can see, one improvement is to the flowering color.

 

 Baptisia 'Cloud Nine' - Photo Courtesy of Plant Delights Nursery

 

 

Baptisia 'Blueberry Sundae' is consistently rated as a top performer (by both Mt. Cuba and the Chicago Botanic Garden trials). This one is a smaller plant at 3' x 3' and is described mostly as an improvement on Baptisia australis. Consider this one for a small garden.

 

Baptisia 'Blueberry Sundae' - Photo Courtesy of Plant Delights Nursery

 

 

For the deep purple lover, there is Baptisia 'Purplicious'. This is another big one, growing to 4' high and wide.

 

 Baptisia 'Purplicious' - Photo Courtesy of Plant Delights Nursery

 

 

For the space-limited or rock gardener, Plant Delights offers clones of a Texas find from the smaller species of Baptisia minor.  Baptisia minor 'Blue Bonnet' only grows to 30" tall, is highly floriferous and has black seedpods.

 

 

 Baptisia minor 'Blue Bonnet' - Photo Courtesy of Plant Delights Nursery

 

 

One of the latest twists is taking the purple flower to a more chocolate-toned flower as in this Baptisia 'Dark Chocolate', a Walters Garden introduction. This one grows 3-3.5' high x 3 wide.  To my eyes, this reads like dark grape jelly.  

 

 

 

Photo from Walters Gardens

 

 

The Yellows

 

Baptisia sphaerocarpa is the original yellow form found in nature. Size: 24-36" high to 18-24" wide.

 

Baptisia sphaerocarpa - Photo courtesy of Mt. Cuba

 

 

Baptisia 'American Goldfinch' is a Hans Hansen/Walters Garden improvement of Baptisia sphaerocarpa. This can form a very large clump.  Size: 3.5' h x 5' wide.

 

Baptisia 'American Goldfinch'

 

A popular light yellow hybrid of B. sphaerocarpa and B. alba is B. 'Carolina Moonlight'.  This was a major improvement in that (1) the plant is a much more pleasing blending yellow than the species' yellow and (2) the spikes are upright instead of pendulous. 'Carolina Moonlight' can get quite tall, however, growing to 3-4 feet high.

 

 Baptisia 'Carolina Moonlight' -Photo courtesy of Mt. Cuba

 

 

There are a host of other yellows too, from 'Screaming Yellow' to 'Blonde Bombshell' -- a Plant Delights introduction whose flowers are also are buttery yellow but showier than 'Carolina Moonlight'.  

 

Tony Avent deems 'Blonde Bombshell'  "the best yellow we have ever grown," but Richard Hawke favors 'Lemon Meringue' which has a high contrast to the foliage that grows very bushy, to 5' wide. Both grow about 40" tall. You be the judge!

 

Baptisia 'Blonde Bombshell' - Photo Courtesy of Plant Delights Nursery

 

Baptisia 'Lemon Meringue' - Photo Courtesy of Plant Delights Nursery

 

 

 

The Whites

 

The white forms of Baptisia have a murky taxonomical history, and the nomenclature has changed during my time of ownership of a white form. As a general rule, white forms bloom later in the season than the blues and yellows. 

 

Baptisia albascens (formerly B. alba) is a Southeastern native white form, with smaller leaves than most Baptisia. The flowers are a pure white. The plant can grow quite tall but generally gets to 4 feet. It has an airy habit and an unusual distinction -- its seedpods dry to tan, not black, like other species. Size is generally 24-36" tall by 16-36" wide.

 

Baptisia alba var. alba (formerly B. pendula) is a form of B. alba. It has thick seedpods that dry black and it can get a little taller, to about five feet. 

 

 

A stunning white hybrid is B. 'Ivory Towers' - a very tall slender form, rising to five feet, but with upright dark purple stems that contrast beautifully with the pure white flowers that rise 30" above the foliage. The stems of this remain very visible all season, an added bonus.

 

 Baptisia 'Ivory Towers' - Photo courtesy of Plant Delights Nursery

 

 

The Pinks

 

Baptisia 'First Blush' is a cross of several other minor species including B. minor, albescens and tinctoria. It is a tall plant - to 52"-- with spikes containing 15" of flowers that emerge as pink buds with a yellow base that age to white against the charcoal grey stalks. This is a late bloomer, starting nearly a month after the early flowering Baptisias. 

 

 Baptisia 'First Blush' - Photo courtesy of Plant Delights Nursery

 

 

Darker pinks are cropping up in the trade too, like B. 'Pink Truffles'. If pink is your preference, keep an eye out for new introductions.

 

Baptisia 'Pink Truffles' - Photo Courtesy of Plant Delights Nursery

 

 

Bicolor Baptisia

 

Other hybrids combine colors rather than blend them. These are eye-catching in photos but where you place them in your garden to please aesthetically can be more challenging.  

 

B. 'Grape Taffy' is a purple yellow hybrid. I imagine it would combine nicely with some yellow flowers while in bloom and is otherwise a blank slate for the rest of the year. This is a shorter hybrid, growing to only 30" high and 36" wide. 

 

 Baptisia 'Grape Taffy'

  

B. 'Cherries Jubilee' is one of the early bicolors that I planted in my garden. To be frank, I've never fallen in love with it and have moved it more than once. It combines beautifully with the copper flowers of Iris fulva, but those don't last long. I find the color reads muddy unless you are close up to the plant. Size: to 3' x 3' in time. 
Baptisia 'Cherries Jubilee' -Photo courtesy of Plant Delights Nursery

 

 

B. 'Pink Lemonade' combines yellow and raspberry purple to make a sight for the eyes to drink. This one grows to 4' x 4' and is a Walters Garden introduction. 

 

 

 

 Baptisia 'Pink Lemonade' - Photo courtesy of Plant Delights Nursery

 

There is also a bicolor that results from aging of the flowers. The flowers of Baptisia 'Lunar Eclipse'  turn from blue to white as time goes by. This one originates from Jim Ault's breeding at the Chicago Botanic Garden. It is a cross of four species and frankly is a quite charming cottage garden looking plant which at only 3' x 3', is on the small size range for Baptisia.

 

Baptisia 'Lunar Eclipse' - Photo Courtesy of Plant Delights Nursery

 

The Unusual

 

Baptisia perfoliata is native to Georgia and South Carolina. This one is all about the weird eucalyptus looking foliage and the yellow flowers atop each stacked leaf. If you are a connoisseur of the unusual you can look for this in roadside ditches. Unlike most other Baptisia, B. perfoliata grows in dead dry soil and sand.

 

  Photo of Baptisia perfoliata from Florida Plant Atlas

 

 

Baptisia Native Species in the Piedmont

 

According to Richard Hawke, there are twenty (20) species of Baptisia native to North America.  Those who live in the Piedmont and want only wild discovered forms of Baptisia (as opposed to intentionally bred hybrids) from the Piedmont will find a narrow selection to choose from.

 

We can confirm the presence in the Piedmont of Georgia of Baptisia alba var. alba (white with black seedpods when dry); Baptisia bracteata (a creamy white form); Baptisia tinctoria (a short but not very garden worthy form); and Baptisia perfoliata.

 

Baptisia australis may have been introduced to Georgia, although a variation of it is confirmed as native. Sources are not unanimous about the native range of B. australis. Its southern range has been pegged at North Carolina and Tennessee per Missouri Botanic Garden, but some less research oriented sources claim it is native to Georgia. Clemson says it is not native to South Carolina, casting doubt that it is native to Georgia. Clemson Fact Sheet.

 

However, a variation called Baptisia australis var. aberrans, known as Eastern Prairie Blue Wild is definitively native to the Piedmont. It has a very open habit and small grayish green leaves. It is said to transplant poorly, however. 

 

 Baptisia australis var. aberrans

 

The good news is that Baptisia is not listed as invasive anywhere in the states, so there are few concerns about using hybridized ones -- especially since they don't come true to seed. 

 

Selection Advice

 

The list of Baptisia goes on and on and shows little sign of letting up. Just glance at the pages of Plant Delights if you need an idea of the breeding going on with these.

 

My suggestion is to dive into the details that work with your garden. Consider the height, width, foliage color, stem color and overall appearance not just flower color. Know that bloom times in different Baptisia can vary by as much as a month, which impacts any kind of color coordination plan you might make. Remember too, that Baptisia are spring bloomers -- April to May at the latest -- and then it is the foliage and seedpod color that will matter beyond the three to four weeks you get to appreciate the blooms. That may suggest tilting towards a certain foliage shades or stems with color or big or small leaved varieties within a floral color palette. Remember that they are a chore to dig to transplant, so choose wisely.

 

For small gardens, Richard Hawke suggests avoiding the larger ones in favor of shorter species such as B. sphaerocarpa and B. australis var. minor. These he likes mixed with peonies, garden phloxes, geraniums, and ornamental grasses.

 

Another suggestion is to buy any pricey cultivars of Baptisia (or any other pricey plant) in bloom, or buy from a nursery that offers good customer service, in case you don't get what you expect. That was my recent experience, believing I was buying an expensive Baptisia 'Ivory Tower' at a local nonprofit's plant sale. When the flower buds began to look yellowish a few days later, I'd knew there had been a mistake and there was nothing I could do about it. Rare is the gardener who has not experienced the disappointment of a plant not reading its own tag a few times! And the more it costs, the worse it stings.  

 

 

Trivia

 

Baptisia's common name of False Indigo reflects that historically it was a substitute dye for authentic Indigo (Indigofera). Indeed, the name Baptisia comes from the Greek "bapto" meaning to dip. But hold on, nothing is as obvious as it seems! The dye didn't come from the purple flowers at all, but from the stems and leaves of a yellow native form, Baptisia tinctoria. And it wasn't even that good a source, as a vast quantities were needed to make just a little dye. Thinking about Baptisia's common name: "False Indigo" brings to mind Gilbert and Sullivan's words: "Oh false one, you have deceived me!" Skip the plans to make dye and enjoy the blooms, instead.

 

Baptisia are sometimes touted as "nitrogen fixers" as many members of the Pea family are, but studies show that it is not a particularly good performer at fixing nitrogen. Nevertheless, that quality may help it perform well in poor soils.

 

Propagating Baptisia

 

Dr. Dirr recently hosted a garden tour where he gave away both seedlings and packets of seeds of Baptisia. All came with a disclaimer: there is no way to know what they might look like! Moreover, hybridized cultivars will not come true from seed.

 

Dr. Dirr says Baptisia seeds are easy to germinate and grow quickly. Soak them for twenty-four hours and discard any floaters. Sow the rest and watch!  

 

Otherwise, you must resort to division if you want to make more of your hybridized cultivars. Early spring is the time advised to try division, but be prepared to dig deep and work hard!

 

More Reading on Baptisia

 

Curious to see how much the market for Baptisia has changed in 14 years, read this wonderfully detailed article from Paula Refi in Perennial Notes from Spring 2010. Spring 2010 Article on Baptisia

 

Mt Cuba studied the Baptisias nearly a decade ago, so their findings on "best" plant don't include quite a few of the cultivars featured above and now available, but they do consider many. Mt Cuba rated 'Lemon Meringue,' 'Ivory Towers,' 'Purple Smoke' and 'Blueberry Sundae' as top performers in 2015. Their reports are always a good read even if all their testing is done in the Mid-Atlantic. Mt Cuba Baptisia 2015  

 

Or read what Richard Hawke had to say about Baptisia in American Horticulture Society a while back.

 

Contributed by Liane Schleifer