Buddleia (butterfly bush) and their flowering ?
By Judylb
Channel Islands ,
Jersey 
I have many buddleia in our garden and most of them flower, varying shades of lilac and purple, which are beautiful. However, I have three bushes that were given to me last spring, they didn't flower that year but grew lots of healthy leaves. I cut them back in this spring expecting flowers this year ( my friend said they were yellow ones . All my other ones are flowering now or dying back but again these newer ones haven't flowered, why is this ?
12 Aug, 2009
Answers
The hybrid between this (B. globosa) and the familiar B. davidii is called Buddleia x weyeriana (with a few named forms of it to boot). This I think sits mid way between them in pruning requirements so not too hard either but a general tidy up, but definitely not a hard prune.
12 Aug, 2009
Hi Fractal, thanks for that, if I'd kept on pruning it I'd never see flowers then. I shall use your advice and hopefully see them next year. Thanks.
12 Aug, 2009
I have quite a few buddlejas xweyeriana "sungold",agathosma,colvilei,crispa and salvifolia.These need pruning after flowering as they will flower on last years wood.Davidii flowers on this years wood
13 Aug, 2009
Bren, thanking you very much for that, as you and Fractal suggested I shall leave on this years growth and just trim back so that hopefully they will flower next year. Thanks again.
13 Aug, 2009
The reason for this is that the yellow types B. globosa in particular will only flower on new growth off older wood. They do not flower on the ends of long fresh growth that is produced after a heavy prune.
If you keep hard pruning B. globosa, it will eventually die.
12 Aug, 2009