20 July 2010
blackcurrant sage and thieving bees
I made a prediction earlier in the year that the most asked question come summer would be "what is that bush with those red flowers?". I was right, but then it is the same each year and I know that "those red flowers" are winners.
To answer the question, it is Blackcurrant Sage, Salvia microphylla. Growing into a loose mound of rather brittle stems, a metre high and across, and covered with bright red flowers from May to December it is a great plant for a well drained position. There are a number of varieties available, this is, I believe, 'Kew Red'. All are very tolerant of drought and poor soil and while preferring full sun seem quite happy in part shade. Supposedly they are not very hardy but do come through most winters unharmed (but only if well drained). The older stems protect the heart of the plant from the worst of the frost so I cut them hard back in spring only after growth has started - before winter can be the death of them. Unpruned they grow much wider and untidier.
Native to Mexico, it has evolved flowers perfect to be pollinated by hummingbirds - the anthers and stamens protrude from the top of the flower to dab on, and take off, pollen from their feathered foreheads. Here it proves a surprisingly good source of nectar for bumblebees, surprising because the beakless bees cannot reach the nectar from the front of the flower, their tongues aren't long enough and the flower is tight-lipped.
To get round this the bees bite small holes halfway down each bloom and they feed from the flowers without pollinating them in exchange. It is interesting that all the holes seem to be gnawed into the right hand side of each flower and that the hole maker isn't the only bee to use each hole, many bees will visit each prepared bloom and fly directly to the hole to feed - obviously the nectar guides, the markings on flowers that are visible in the ultra-violet spectrum that bees use, are ignored as unnecessary and they don't waste time trying the front door. Sneaky thieving bees.