Tough, prolific and colourful drought-tolerant plants are becoming increasingly valuable and preparing a lecture on new perennials today, it struck me again how baptisias are under rated. And there’s been a flurry of new introductions in recent years which have greatly expanded the color range. They combine drought tolerance with an imposing presence and prolific flowering – and unlike lupines, which are rather similar in their general appearance, they don’t suffer from those monstrous gray lupine aphids and are less troubled by powdery mildew.

At the Chicago Botanic Garden Jim Ault, who brought us the Meadowbrite echinacea hybrids, has now introduced four hybrids in his Prairieblues  Series. Starlite Prairieblues is a hybrid between B. australis and B. bracteata with brilliant blue and white flowers on tall spikes. In a much darker blue, Midnight Prairieblues is a cross between B. australis and a seedling from a cross between B. tinctoria and B. alba. Opening yellow then developing rusty orange tints Solar Flare Prairieblues is another complex hybrid involving those same three species. Finally, Twilight Prairieblues is a bicolor in deep purple and yellow, this time derived from B. australis and B. sphaerocarpa.

At the North Carolina Botanic  Garden Curator Rob Gardener selected a hybrid of B. sphaerocarpa and B. alba he named ‘Carolina Moonlight’, with long buttery spikes over blue-tinted foliage. He also selected ‘Purple Smoke’, a hybrid of B. minor var. aberrans with blackish stems topped with smokey purple flowers.

All these baptisias are native to the North America; some overlap naturally in their distribution and some are isolated from each other. But bringing them all together in a controlled way creates unique genetic combinations – and unique plants with prolific flowering in new shades.

But the old fashioned way also works. Tony Avent of Plant Delights Nursery in North Carolina spotted an unusually vigorous and upright plant of B. alba, with dramatic spikes of white flowers, growing in nearby Wayne County. He introduced it as ‘Wayne’s World’. In Arkansas native plant guru Larry Lowman selected B. sphaerocarpa 'Screamin' Yellow' with unusually brilliant yellow spikes.

Remember that all these baptisias love the sun, tolerate drought and are hardy (zone 4 or 5) and easy to grow. I have to say that mine are not in full sun and so are less prolific than I would like. They also make great cut flowers; cut the stems when about a third or a half the flowers are open and put them directly into warm water contain flower preservative. They should last well.

Buy these baptisias by mail order in North America from Great Garden Plants,  Plant Delights Nursery, White Flower Farm and North Creek Nurseries. Not all are yet available in Britain, but check the RHS PlantFinder to find who's selling what - the new 2008 edition, with new listings, will be available online in early April.