One of the most endearing traits of the accommodating Hyacinthus is that it lends itself so well to forcing bloom. That's a fancy way of saying that you can make the plant flower whenever you want. The favorite time for forcing hardy bulbs is during the long, cold, dreary winter months. It brings the cheerful promise of a faraway spring that really will come once again. Plant your hyacinth bulbs indoors in mid-September if you'd like for them to bloom around Christmas. Start them about mid-October for Valentine hyacinths, or in mid-November for spring blooming.
Cover the bottom of a well-draining 7-inch clay bulb pot with 1/2 to 1 inch of gravel or small stones. Combine equal parts garden loam, coarse sand and peat moss to create potting medium. Plant three or four hyacinth bulbs in this mixture, spacing them about an inch apart. Cover the bulbs with 1/2 inch potting medium.
Water the hyacinth bulbs thoroughly, but don't soak the soil to the point of being wet or soggy. Don't allow them to dry out.
Put the pot of hyacinth bulbs in a dark, unheated room for about 10 to 12 weeks. They'll need several dark, cold months to form roots. Keep the temperature between 35 and 48 degrees Fahrenheit. It's very important that the temperature is never allowed to rise above 65 Fahrenheit. The basement, garage or a shed work well for this. Leave them stored until at least the first week in January.
Water the hyacinths about once weekly to keep the soil evenly moist but not soggy or wet.
Place the pot in a dim, slightly warmer spot such as a closet or kitchen cabinet. The ideal temperature range is about 50 to 60 degrees Fahrenheit for the first week, or until shoots begin showing some green color. You can then begin gradually acclimating the hyacinths to more light. Check them once weekly. Keep the soil surface just barely, but evenly, moist.
Move the hyacinths to a slightly brighter spot each week until the foliage is about 6 to 8 inches tall. Move the hyacinths to the brightest spot in your home when the foliage is about 8 inches tall. A sunny window is a perfect spot. Cool temperatures around 55 to 65 degrees are best for blooming.