Posted: 11/08/2014 at 11:07
I really do think pinching back regularly, doing the Chelsea chop, choosing varieties that are slightly shorter(.e.g. Heleniums) removing long stems on dahlia and choosing plants that stand up to the wind (e.g. Acteas) is the way to go.
I have lots,of tall and very tall perennials in the garden amd all are still in fine fettle. Cannas, bonariensis, veronicastrums , agastaches all do well against wind as do many tall grassss that aren't a bit miffed about wind or rain.
Always stake dahlias early, lupins have their spikes secure if they are ESP large, delphiniums always staked.