I did a butternut lemongrass blond back in the fall. Didn't want to be bothered preparing fresh and I understand you can get vegetal flavors using too much and too long in the secondary. I used dried, about 3 grams at the end of the boil and 3 grams dry grass for 7 days. I thought dried spices and the like were more potent than fresh. Couldn't really find the lemongrass.
"...allowing the beer to become what it is." -- Jason Yester, Trinity Brewing Co.