Hardy annual orlaya grandiflora (seed from http://www.sarahraven.com/) was the most asked about plant in my garden on the Open Days.
We raised over £1200 for the Scotland's Gardens charities - Maggie's Cancer Caring Centres,The Queen's Nursing Institute Scotland,The Gardens Fund of the National Trust for Scotland and Perennial.
We don't ask the gardeners if they will do it again until they've had a while to recover!