February 2006 issue of the Cornell Flower Bulb Research Program Research Newsletter:
One of the ongoing issues for pot hyacinth growers in North America is “floppy stems”, where the heavy flower causes the stem to flop over while in full bloom. Obviously cultivars differ in “floppiness”, and production schedules (such as avoiding excessive cold weeks), and probably the cooler environment (too warm, or soil too wet) also exacerbate the issue. If you are selling hyacinths with floppy stems, the only option is to stake them, a very costly proposition.
Read the whole article. Starts on page 3.