Made famous by Dutch breeders, but native to lands to the east of the Mediterranean Sea, the hyacinth (Hyacinthus orientalis) announces winter’s end with intensely sweet, fragrant flowers. The hyacinth grows from an underground bulb, just like a tulip or daffodil. Only one flower stem develops in each hyacinth bulb, so once that flower stem blooms, no others replace it. The leaves make food and replenish the bulb so it may hopefully produce another flower stem after next winter.
The Hyacinth Bulb
Sometimes hyacinth bulbs are forced atop a jar of water to sustain roots.
That a hyacinth grows from a bulb explains why cutting off an old flower stem doesn’t yield another flower. Unlike other annual or perennial flowers, the hyacinth doesn’t develop any above ground stems or buds. The flowers of the hyacinth originate within the fleshy tissues inside the bulb. Once the bulb is planted in fall, the cool and moist soil conditions allow the lone flower stem with numerous buds toform. Only after the cool dormancy and the soil warms in late winter, does the flower stem poke up from the ground and later bloom.
Each bulb produces only one hyacinth flower stem with blossoms.
Bulbs that persist in the garden soil develop small bulblets or daughter bulbs. After flowering, the leaves remain to photosynthesize sunlight and store food in the bulb. Besides making the bulb larger, some energy goes into making new bulbs in a clump. If the bulblets grow large enough, they too produce a flower stem next spring. An unknowing gardener may have planted one bulb, but two or three years later, a mass of leaves and multiple flower stems appear. The flower stems each arise from singular bulbs in the clump.
The Need for Cold
Hyacinth leaves growing from the bulb.
The leaves of a hyacinth plant naturally wither by the end of summer and go dormant. You cannot water or fertilize the bulb when it’s dormant to coax another flowering. The hyacinth must also be exposed to 12 to 15 weeks of chilly soil conditions in winter. Otherwise, the flower stem and blossoms will not develop inside the bulb. If you purchased hyacinth bulbs and immediately plant them in soil hoping for a flower, only leaves grow.
The Grape Hyacinth
A mass planting of blue-colored grape hyacinths near red tulips.
Another spring-flowering plant is called the grape hyacinth (Muscari spp.). It’s not closely related to the hyacinth discussed, but it grows in similar fashion with identical needs. If you cut off the old flower stem from a grape hyacinth, another flower stems doesn’t grow. The same life cycle of summer dormancy followed by long, cool-soiled winter dormancy is needed for it to bloom again in spring.