Plant Taxonomy, Botany of Hyacinth Flowers
Plant taxonomy classifies Dutch hyacinths as Hyacinthus orientalis. The Dutch type are the best known across the bulk of the northern half of the temperate zone. Other common names for them include "garden" or "common" hyacinths.
They are poisonous plants if ingested in large quantities.
Dutch hyacinth flowers are planted in fall and bloom in early spring. Their leaves are blade-like but curl inwards along the entire length, rather like when you fold your tongue into a U-shape lengthwise (if you can do that!).
Flowers occur in clusters on a spike 6-12 inches long. The waxy, fragrant flowers resemble little starfish when fully open (prior to that, they are bell-shaped). Colors include red, white, blue, purple, pink, lavender, yellow and various odd-ball colors like peach and salmon. 'Midnight Mystic' produces black flowers.
Growing Zones, Sun and Soil Requirements
Grow hyacinth flowers in planting zones 4-8. Despite commonly referred to as being "Dutch," these flowers are indigenous to the Near East. They became associated with the Dutch due to the propagation and cultivar development of the flowers undertaken by growers in the Netherlands.
They have a chilling requirement, which poses a challenge in more southerly climes. A workaround employed in warm areas is to dig up bulbs in fall, keep them refrigerated during winter, then replant next spring. However, even in cooler regions, some people simply buy new hyacinth bulbs every other year (see below).
Grow the plants in full to partial sun and in a well-drained friable soil. Use compost as a soil amendment when planting (and periodically thereafter, along with bone meal, to fertilize). A location in partial sun, particularly in warmer climates, may be beneficial, as a pounding sunshine can cause the flower colors to fade (this is rarely a problem for me here in New England (U.S.), where clouds dominate our springs).
When to Plant Hyacinth Bulbs
Planting should be done in the fall. The best time to plant is determined by your planting zone:
- For zone 3, plant in September
- For zones 4-5, plant in October
- For zones 6-7, plant in November
How to Hyacinth Bulbs
To prepare the ground for planting, loosen the soil down to a depth of about 1 foot. When planting, always remember to leave the pointy end of the hyacinth bulb sticking up. Follow instructions on the package that the hyacinth bulbs came in to determine planting depth. Fertilize hyacinth bulbs at planting time with bone meal.
Many people prefer the look of one color of the flowers massed together, rather than mixed colors.
Other Types of Hyacinth Flowers
Do not confuse the Dutch type with grape hyacinth (Muscari botryoides). Grape hyacinth plants bear smaller flowers and are so called because the clusters resemble grapes.
Muscari botryoides blooms at about the same time as Hyacinthus orientalis; one year, my Dutch hyacinths were 2 weeks ahead of my Muscari botryoides. You may well have these two types of flowers growing in the same bed (they can be grown in roughly the same span of zones).
Water hyacinths (Eichhornia crassipes) are aquatic. Hardy in zones 9-11, they may become invasive plants if grown in a warm climate where they are not native.
Origin of the Name in Greek Mythology
Hyacinthus was loved by the Greek god, Apollo, who accidentally killed him in a discus throwing contest. A flower sprouted up from the dead youth's blood and was named in his honor. In this sense, the story behind the name of the flower is not unlike that behind the naming for Narcissus.
Deadhead flowers after blooming -- not to promote re-blooming, as you would for many other plants, but to channel energy into bulb development rather than setting seed.
But leave the foliage alone until it has completely died back (signaled by yellowing) on its own, so that it can continue to send energy to the bulbs, using photosynthesis. Consider it a down payment on next spring's flowers, as you want them to be able to store as much energy as possible.
You can divide the bulbs every couple of years to try to help them maintain their blooming prowess. Some people divide in fall, others in spring (after blooming). I prefer fall as a time to divide bulbs. When you divide bulbs in spring (before the foliage has died back), you may start out with depleted "stock," that is, bulbs cut off prematurely from their energy source (since the leaves may be damaged during the division). By contrast, in fall they will have already stored all the energy they are going to store for next year's blooming. Admittedly, though, a drawback to fall division is that it is more difficult to find the bulbs in autumn.
Either way, do not expect too much out of your hyacinth bulb division. The "flower power" of hyacinth plants does simply peter out over time, at which point you may wish simply to buy new bulbs.
After the ground has frozen in late fall or early winter, apply mulch over your bed to protect hyacinth bulbs, if your region experiences severe winters.