Autumn Joy Sedum, pictured above, is easy to grow and widely available. They are from a large family of succulent type plants that range from ground covers to this upright large perennial. The flowers begin greenish in August and gradually turn from pink to burgundy as the nights get longer and colder, leave standing over winter for winter interest and cut down in the spring before new growth in April. As these are succulents they are suited to hot, dry, sunny locations but I seem to have no problem growing in a little dappled shade too. All the Sedums can be propagated, quite easily from stem cuttings in the spring and early summer, simply snip off a sizable piece remove the bottom leaves and bury the stem in the ground, keep moist and viola, new plant. The ground covers easily root from any piece of stem too! A great companion and contrast to the greenish leaves of Autumn Joy is of course the deep red-burgundy version sometimes sold as Stonecrop, Black, also widely available, is pretty much the same plant but cultivated in this colour, below.
Turtlehead, Chelone obliqua, is another late bloomer, given a long enough fall that is not too frosty these plants will bloom from around late August until the first very hard frost. I hear they are available in Pink and White but I was only ever able to find Pink, so I will forgive the colour as the flower heads really do look like little turtle heads! I grow this large perennial in part shade as it likes to be moist, it seems to require no special care, is easily divided in the spring and is not bothered by pests, I recently found out deer won't eat them either. They make a good cut flower, like if cold weather is looming, and many nectar loving insects also love them!
Although Turtlehead is native to Eastern North America it seems to thrive in Calgary too. As you can see in the bottom photo this plant grows to about 3 feet high and blooms beside the changing fall leaves!
Fall Asters, well there are many many kinds! Here is a general idea of what they look like. I grow the purple Italian variety, that I got from an old neighbour, in the picture above, but they are available in a variety of heights and colours from white to yelow, red to purple and pink and everything in between. When you purchase Asters just make sure they are the perennial kind suited to our climate, there are a few developed in Canada in Morden and many others such as Italian and Professor Kippenburg that are very hardy too. Asters like sunny sites in warm areas, I give them no special care and they reward with blooms from September thru October! The Italian Aster I have sometimes blooms well into November, shirking off snowfalls and -10C weather like it was nothing. One often sees the more tender Asters for sale at grocery stores or where ever, they are fine and lovely but remember that they do not like frosty nights, the blooms will get damaged in too cold of weather, they are more suited to the West Coast or more Southern areas.
Cimicifuga, or if thats too hard, Bugbane, Snakeroot, Brunette
I remember some controversy about the scientific name of this plant but it is still being listed as Cimicifuga so lets just leave it at that! I don't really grow it for the flowers as it usually gets frozen before it can, but when it does I suppose it's quite interesting. This plant is mostly grown in our area as a shade tolerant and moisture loving foliage perennial. This is a tidy and not overly large perennial, given a warm enough season it begins blooming in September in my yard.
Annuals, there are a variety of annuals that can stand a little cold weather and shorter days. Sunflowers certainly seem familiar as a fall flower and seem to love every last moment of the fading summer sun. Others like Sweet Peas, Marigold, Snapdragons and Petunias can take a light frost and bloom for weeks after, just keep watering! I remember cutting sweet peas well into October one year!
When we are looking at months of the upcoming winter it's nice to hang on these late bloomers as the last vestige of our short warm seasons.