Last month, I wrote how blue is not a usual colour for flowers in the autumn. How wrong I was. Perhaps I’ve subconsciously been seeking them out, but blue flowers are all over the place in my garden just now – the vitex I wrote about, salvias, ceanothus, and aconitums. But possibly the bluest of the lot are on ceratostigma willmottianum ‘Forest Blue’.
This is classed as a sub-shrub. To me, that means it can’t make up its mind whether it’s a shrub (which doesn’t need cutting down in the spring) or a perennial (which does). I’ve tried both and it doesn’t seem to make any difference to the eventual size of three feet. Leaving last year’s growth intact does lead to it starting to flower a bit earlier, but as it starts in July and continues right through into at least October, that’s not really a problem.
The accepted wisdom is to grow it in a sunny position in moist but well-drained soil. Here it has to cope with a modicum of shade for part of the day and a soil on the heavy side but still seems happy enough. Far from giving me the autumn blues, this lights up my day.