Hyacinths are bulbous perennials known for their dense, fragrant spikes of flowers that signal the arrival of spring. The practice of propagation allows gardeners to increase their stock of these vibrant plants without purchasing new bulbs each season. Since hyacinths naturally multiply slowly, specific techniques are employed to accelerate the production of new bulbs, called bulblets. These methods range from simple separation of naturally occurring divisions to more intensive, forced multiplication techniques.
The Simplest Way: Relying on Natural Offsets
Hyacinth bulbs naturally produce small daughter bulbs, known as offsets, around the base of the main bulb over time. This is the least invasive method, relying on the plant’s inherent growth pattern. However, hyacinths are generally reluctant to produce offsets, offering a slow propagation ratio of approximately one to two new bulbs annually per mature plant.
To harvest these offsets, the parent bulb should be lifted from the soil in late spring or early summer after the foliage has naturally died back and yellowed. The bulbs are then cleaned, and the small bulblets are gently separated from the basal plate of the mother bulb. These newly separated offsets are typically too small to flower immediately and must be grown for several seasons in a nursery bed to reach a sufficient size.
Forced Multiplication: Scooping and Scoring the Bulb
Specialized techniques called scooping and scoring are used to force the production of numerous bulblets. These methods intentionally wound the basal plate, which is the flattened stem tissue at the bottom of the bulb where roots originate. By destroying the central growing point, the plant is stimulated to redirect its energy into forming new bulblets.
Scooping the Bulb
Scooping is an intensive method that maximizes the number of new bulblets produced from a single parent bulb. The technique involves completely removing the entire central portion of the basal plate using a sharp, sterilized knife or a specialized scoop.
After scooping, the exposed wound is treated with a fungicide powder to prevent fungal infection and rot. The treated bulbs are then placed upside down, with the scooped basal plate facing up, in a warm, dark, and humid environment. Incubation conditions generally require temperatures between 68°F and 77°F (20°C to 25°C) for approximately three months. Under these conditions, the parent bulb can produce up to 30 to 60 small bulblets along the edges of the wound.
Scoring the Bulb
Scoring is a slightly less aggressive method than scooping and typically results in fewer, but often larger, bulblets per parent bulb. For this technique, the basal plate is not removed entirely but is cut with several deep, intersecting incisions. The cuts should extend deep enough to reach the inner, fleshy scales.
Similar to scooping, the scored bulb must be dusted with a fungicide to protect the wounded tissue. The bulb is then incubated under the same warm, dark, and humid conditions for several months. The cuts stimulate the formation of bulblets along the incision lines. The bulblets generated from both methods will typically need four to five years of subsequent growth before they develop into mature, flowering-sized bulbs.
Propagation Through Seed Collection
Growing hyacinths from collected seeds is a viable method for propagation. This approach is not recommended for gardeners seeking to quickly multiply their existing stock. Seeds are collected from the flower stalks after the blooms have faded and the resulting seed pods have dried and split open.
The seeds are generally sown in the autumn in a well-draining mixture of soil and grit. The process requires significant patience because a seed-grown hyacinth must dedicate its initial years to developing a sufficiently large bulb structure underground. New hyacinths grown from seed typically require a minimum of five to seven years before they reach a mature size capable of producing a flower.