Place the hyacinth bulb in the cup, root end down and growing end up (growth may already be showing) so the base is barely touching the water. Position the vase on a bright windowsill and watch as it begins to bloom. Periodically change the water and keep the level at the base of the bulb. Turn it every day to keep it growing upright. Forced bulbs do not usually make the transition to outside garden plants, so toss them in the compost bin once the nearly two-week fragrant show is over.