Hyacinths are one of the many spring flowering bulbs that grace gardens when spring is just beginning. Hardy perennials, hyacinth grow well in most climates. There are many varieties of hyacinth, from the grape hyacinth with its tightly packed purple petals to tall and stately varieties that have a profusion of blooms covering their flower stalks. Hyacinths grow from an underground bulb structure that must be properly cared for to ensure the hyacinths bloom at their best each year.
Apply 2 pounds of 5-10-10 fertilizer to every 100 square feet of hyacinth bulbs in spring when foliage first begins to grow. Apply the fertilizer around the foliage, taking care not to get it on the young leaves, because it can burn them.
Replenish the mulch around hyacinth leaves so it remains at a 2 to 3 inch depth. The mulch preserves soil moisture and protects the bulbs from temperature fluctuations.
Water the bed as necessary to keep it moist but not soggy. Weekly deep watering is usually sufficient. Begin watering once the soil thaws and begins drying in spring and continue to water until the ground freezes the following fall. Even dormant bulbs need some moisture.
Cut off the flower stalk just below the lowest bloom once the stalk has stopped flowering. Use a pair of clean shears and discard the stalk, because dead plant material in the bed can become a haven for pests and disease.
Cut the foliage off at ground level once it has yellowed and died back on its own, usually six weeks after blooming stops. The foliage must be left on until it dies naturally, because the leaves replenish the nutrients in the bulb so the hyacinth can bloom again the following year.
Dig the bulbs and divide in the fall every three to five years or when the hyacinths stop blooming profusely. Dig around the bulbs, then slide the trowel under them. Lift them from the ground. Replant the healthiest bulbs in the garden.