When Can You Plant a Hyacinth Bulb That You Buy in Spring?

Bulb Storage

• When purchasing bulbs in spring -- or fall -- inspect them for mold, cuts, bruises or other types of damage. Healthy hyacinth bulbs are firm with a protective sheath around them. Do not save moldy or soft bulbs for planting because they can rot in the soil and affect neighboring plants. Store new and previously planted bulbs in a dark, dry place in temperatures between 50 and 60 degrees Fahrenheit – you can put loose and loosely packaged bulbs in a cooler or refrigerator. When digging bulbs from the ground, loosen excess dirt and hose them off with a stream of water. To remove moisture, lay the bulbs out for about three or four days -- as long as needed for their skins to become completely dry. Laying bulbs out separately on a newspaper or hanging them in bagged netting allows for air flow and circulation.

Hyacinth

• Common hyacinth bulbs (Hyacinthus orientalis) grow in U.S. Department of Agriculture plant hardiness zones 3 to 10. They produce small, star-shaped flowers in various colors. They have long, thin green leaves and flowering spikes that grow up to 12 inches high. Grape hyacinths (Muscari botryoides), as their name suggests, feature spikes of bright purple, rounded flowers. Hardiest in USDA zones 3 to 9, grape hyacinths thrive in full sun.

Chilling and Planting

• Hyacinth bulbs require six to eight weeks of chilling to bloom in coastal areas and up to 12 weeks in cooler climates. Soil temperature should be below 60 F, advises Clemson Cooperative Extension. Bulbs that do not chill long enough may produce short stems that grow close to the ground. When planting hyacinths in the fall, choose a date about six to eight weeks before the first hard frost, usually September and October for USDA zones 3 to 6 and November and December for USDA zones 7 to 10.

  Place the bulbs, with pointed ends facing upward, 4 to 6 inches apart and 6 to 8 inches deep, into well-draining soil. Soil pH for bulbs is best at 6.0 to 7.0. Cover the ground with soil and water thoroughly. Placing mulch over hyacinth and other bulbs helps keep the soil from freezing.

Container-Grown Hyacinths

• Hyacinths, like other bulbs grown indoors, can be forced to bloom through winter months. Bulbs are dormant in late summer with soil temperatures above 60 F. Although bulb roots grow as the temperature drops, you can alter the cycle to force the plants to bloom when desired. Place bulbs in containers with drainage holes and potting media with soil, sphagnum moss, vermiculite and perlite. As with outdoor bulbs, container-planted hyacinths need about three months of chilling, such as in the refrigerator, before they bloom.

  To force the bulbs after chilling, water the soil as needed and place the containers in a cool location. When greenery emerges, place the pots under filtered light, because drastic temperature changes may harm the plant. Increase sunlight exposure as the plant grows. Typically, blooms appear in two to three weeks.