I got some too last year and didnt cut them down consequently they have now re-sprouted from their woody stem, I think you are supposed to cut them back after flowering (they will flowering in November last year!) down to ground level that way you get fresh stem each year, I think they only came onto market last year which is why I havent been able to find anything, but someone else might no better to me as growing flowers is very new to me, much prefer to grow to eat !