In two of my gardens now I’ve come across a Banksian rose, and in both cases the owners didn’t know what they’d got. The sad thing is, that meant the roses had never flowered – because they’d been pruned in the late winter, like regular climbing roses.
Banksian roses are wonderful, though very rampant, climbers which flower on last year’s growth. So every time you clip them, you’re taking flowers off. Instead of pruning them at this time of the year – which will remove all last year’s growth and therefore this year’s flowers – you have to wait until the plant has flowered in May/June.
Then you either remove entire stems to reduce the size (and these are really, really big plants – they cover entire houses without even thinking about it) or take back side shoots to 3-4 buds. That’ll give the plant plenty of time to produce new wood to flower the following year.
If you do prune it right, the plant will reward you with the most beautiful flowers – clusters of palest yellow buttons in profusion all over the plant. The species is white, but most plants turn out to be Rosa Banksia lutea – the yellow version, and a beautiful shade of yellow it is, too.