Betsy, like any blooming plant, the energy required to produce seed is significant. All of those great multi-colored hosta with all of the neat shapes and textures are all hybrids. A large proportion of them are sterile and won't produce any seed. Those that do produce seed most likely will not grow true to their parent. Cut the top off, just below the flower head. Leave the rest there to die off naturally. Because it is still green, it can contribute to the energy collection for the base plant.
Otherwise, it's more a factor of adequate water and soil nutrients.
