When to Plant Grape Hyacinth?

Initial Planting

• Fall provides the best time for planting new outdoor hyacinth bulbs. The plants produce new root and foliage growth over the winter months then begin blooming in late winter and early spring. Planting six to eight weeks before the first expected fall frost gives the bulbs time to establish in the soil before the ground begins to freeze. By establishing a healthy root system in the warmer soil they survive the winter months without damage.

Divisions

• Grape hyacinth bulbs reproduce themselves underground each year. The additional bulbs produced may become crowded within two to three years, requiring divisions. By dividing and replanting the extra bulbs you can expand your hyacinth bed without purchasing more plants. The best time for division and replanting occurs after the foliage dies back, approximately six weeks after the spring bloom. Waiting until after early summer dieback allows the hyacinth foliage to collect the optimum amount of nutrients in the bulbs for the next year's bloom.

Forcing Indoors

• Forcing hyacinths indoors provides you with the brightly colored flowers during the winter months. It takes grape hyacinths approximately 18 weeks to flower from forcing, with 14 weeks of that period spent in cold treatment. Planting the bulbs in a pot of soil and placing it outdoors in a cold area or in a refrigerator for 3½ months provides the necessary cold to force dormancy and later flowering. After cold treatment, placing the pots in a sunny indoor area encourages the bulbs to put on new growth and flowers. Most forced hyacinth begin cold treatment in September or October for midwinter flowering.

Transplanting Forced Hyacinth

• Hyacinth bulbs only tolerate forcing once, but transplanting them outdoors afterward allows you to enjoy the bulbs and flowers for many years. Bulbs forced in soil tolerate transplanting in late spring. Potted hyacinth must receive water, sun and soluble fertilizer after the bloom period completes indoors so the foliage and roots can absorb the nutrients needed to replenish the bulbs. Once the foliage dies back on the plants naturally in spring, the bulbs are ready for transplanting into the garden.