Several years ago I made a conscious effort to add more perennials that would bloom at times of the year when few other plants were blooming. I added gallardia, cestrum and cuphea to cover the hot gap from late June until fall. For winter I already had color from camellias, hellebores and my edgeworthia, but I wanted more, especially since winter is my least favorite season. Anything I can get to bloom then delights me.
Iris unguicularis (commonly known as Algerian iris) is native to North Africa, Greece and parts of the Middle East. I planted mine two falls ago, and last winter I think it bloomed once or twice. This year it first opened in November, had a couple of blossoms in December and has now bloomed twice in January. I have read that it is a opportunistic bloomer waiting for warmer spells of weather during the winter months and should continue until March. The buds are apparently freeze-proof, but the open flowers are not. They are typically shades of blue, but white and pink cultivars exist as well. The strap-like evergreen foliage reaches 12-15" tall, and the flowers tend to open a little below that. They are sweetly fragrant, but aging knees make you think twice about getting down to enjoy the aroma. This iris prefers full to part sun, lean soil with smart drainage, likes dry summer weather and is hardy from in zones 7-9. These conditions are not a problem for me.