When we first saw a specimen of False indigo (Baptisia australis) blooming outside a local nursery almost ten years ago, we had no idea what it was, but thought it looked like some weird bush version of a Sweet Pea (a flower we try in vain to grow with little success). We were so taken by the dramatic tall stalks of blue flowers that we decided then and there that we had to have this plant in our garden, which was just in its infancy back in 1999. So, we inquired inside as to what it was and were lucky enough to be able to buy a specimen to take home with us. The ones for sale were small, only about five inches tall at the time, so we bought two just in case they didn't like where we planted them.
The first year they didn't grow much at all, but as we were to discover later (after some research) most of its activity was spent growing underground. So we had to content ourselves with making sure it was well pampered the first year and then waited patiently until the next spring to see if it would return. Return it did, and though it wasn't huge its second year, it did put up several spires of flowers, much to our delight! In successive years, it has increased in size and area and at this point usually grows to a bush size of about four to five feet in diameter once it has finished blooming. One of the (many) interesting things about False Indigo is that when it emerges in the spring, the shoots look like giant asparagus tips poking out of the ground ... but these soon turn into the stalks that will carry the leaves and flowers for each year's blooms. This year, unfortunately due to the April freezes, it hasn't gotten very big at all, and we wondered if it would bloom at all ... but in the last week or so it has put up a limited number of bloom spires and made a good effort to provide its usual late spring show. It won't be as big as it usually gets, but that's fine, just as long as it's happy enough to continue blooming for us!
It's really a pretty easy and showy perennial to grow, and it has the great advantage of not having garnered a great deal of popularity with garden variety gardeners. We see a bit of it here and there around town (some of which has come from this original plant that we've spread around a bit), but it certainly hasn't achieved the kind of common presence that other perennials have. It has a great hardiness range from Zones 3 to 10, and is tolerant of both wet and dry soils, and in the spot where we have it planted, it definitely wins awards for being very drought tolerant, as the soil is not too rich and dries out quickly.
After the blooms are spent, each one produces a seed pod that matures to a charcoal coloured hue, and if you're planning on collecting seeds, you should let them dry on the plant until you can hear the seeds rattling around inside. If you do nothing, the pods will eventually pop open and the seeds fall to the ground, where, if left to over winter, will often produce new plants the following spring. We've allowed a few of the younger plants to remain in place, but since we have gotten so many compliments on this magnificent flower, we usually just dig them up and give them away to someone we know will give them the love and attention they need the first year in order to return and reward the lucky recipient with its beauty in the following years.
Once established, False Indigo is virtually maintenance free, except for the need to cut back the dead growth in the spring before it re-emerges. It's not fussy about the soil, and actually seems to thrive in poorish soils ... all the while enriching them, since it does belong to the legume family. And once the pods have set on, the foliage makes a great filler for flower arrangements (as does that of peonies, by the way). I've read that some people use the pods in dried arrangements, but we've never considered them attractive enough for that use ... besides, they'd eventually pop open and drop their seeds indoors, where any chances for them to germinate would be practically nil. If you should choose to plant this outstanding plant in your perennial garden, my suggestion would be to just let it do its thing and progress through its annual cycle. If you do, you'll be rewarded for years to come from this sturdy and gorgeous plant.
Note on the photos: The first two are from Spring 2006, which was a better year for this plant, and the third is from May 30, 2007, showing the less robust growth it's had this year. Next year we hope it will be back to its usual height and floriferous abundance.