Grape Hyacinth Plant Profile

Grape Hyacinths, Muscari Bulbs
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Grape hyacinths are small spring-blooming bulbs, so named because of the tight little flower clusters that resemble grapes. Although the Muscari genus was previously categorized in the Liliaceae family (which also contains true hyacinths), it is now considered to be part of the Asparagaceae, or asparagus family. Look at other members of this family to observe superficial similarities: Lily-of-the-valley, brodiaea lily, and asparagus plants also have flowering umbels that emerge from a central stalk.

Regardless of plant taxonomy and who is related to what, grape hyacinths are little garden workhorses that can light up the early spring flower garden for years with little care. Grape hyacinths generally bloom in April or May, with blooms lasting for about three week.

Some gardeners describe the tightly packed florets of grape hyacinths as looking like an upside down vase on a stem. In most varieties, each floret looks like a little grape on a short stem, with dozens of these little stems attached to a central stalk. Many varieties of grape hyacinths display that rare crystal blue color so many gardeners covet, but they have none of the fussiness that some blue flowers possess. Other colors are also available; the white, pink and yellow varieties of grape hyacinth provide a welcome contrast when planted with the blue types.

Botanical Name Muscari armeniacum
Common Names Grape hyacinth, muscari, bluebells
Plant Type Bulb
Mature Size 6 to 9 inches
Sun Exposure Full sun to part shade
Soil Type Medium moisture, well-drained soil
Soil pH 6.0 to 7.0
Bloom Time Early spring (generally April)
Flower Color Royal blue
Hardiness Zones 4 to 8 (USDA)
Native Area Western Asia, southeastern Europe

How to Grow Grape Hyacinth

Like most spring-flowering bulbs, fall is the best planting time for grape hyacinth. Choose a site with average soil that drains well; grape hyacinth bulbs will rot if planted in a site that remains wet. One of the appealing traits of this bulb is the ease with which you can plant it. Space the bulbs approximately 3 inches apart and 3 inches deep. You can take out a spade full of soil and plant a handful of bulbs all at a time, making it possible to install a large drift in under an hour. If you wish to try your luck with the bulbs in zone 3, plant them 5 inches deep and provide mulch cover to help them perennialize. Grape hyacinth bulbs form ever-enlarging colonies over the years, but the plants are not invasive.

After grape hyacinths are finished blooming, they produce circular green seed pods that can linger well into summer. Remove these pods when the blooms are finished to allow the plant to direct its energy into the following year’s blooms. You can also shear the foliage when it starts to yellow.

Unlike many spring-blooming bulbs, grape hyacinths produce a flush of grass-like foliage late in the summer or early fall, and this foliage should be left in place until the plants finish blooming the following spring. This foliage helps nourish the plant; only during the onset of summer dormancy is it okay to remove the leaves until new foliage appears once more.

Light

Grape hyacinth does best in full sun but tolerates part shade. Remember, though, that many sites that are shady in summer are quite sunny in the spring before trees have leafed out. These are ideal areas for planting grape hyacinths and many other spring bulbs.

Soil

Planting grape hyacinth in any well-drained soil will produce good results. Grape hyacinths are most fond of somewhat sandy soil, but they do well in pretty much all but the soggiest soils.

Water

Grape hyacinths like a fair amount of moisture during the spring, but the soil should be allowed to dry out as the season progresses. This helps to prevent bulb rot issues.

Temperature and Humidity

This plant does nicely in all climate conditions within its hardiness zone range. Grape hyacinths require a cool winter period in order to bloom, so unseasonably warm winter temperatures may cause bloom failure the following spring.

Fertilizer

No fertilizer is necessary for grape hyacinth, but they may benefit from sprinkling 1/4 cup of bone meal for every 100 square feet of soil once each year.

Propagating Grape Hyacinth

This plant spreads itself quite readily, and drifts of grape hyacinth will gradually spread over large areas. It is a fairly easy matter to dig up clusters of bulbs and transplant them wherever you want.

Growing Grape Hyacinths in Containers

Muscari in Containers
Ellen van Bodegom/Getty Images 

Buy enough muscari bulbs to force some for indoor flowering in containers. The bulbs need about 10 weeks of chilling to prepare them for blooming. Bulbs need temperatures of about 40 degrees F. to achieve the dormancy that will lead to growth, so the refrigerator is a perfect place to prepare your grape hyacinth bulbs. Time the beginning of the chill period for about 22 to 24 weeks before you want the bulbs to bloom.

  1. For blooms in late January through March, chill the bulbs at a temperature of about 40 degrees for about 10 weeks in September through October.
  2. After chilling, plant 12 to 15 bulbs in a bulb pan or other container at least 6 inches around and 6 to 8 inches deep. Moist potting soil is preferable. Place the bulbs about 1 inch apart with the exposed tips pointing up.
  3. Move the pot to a cool, dark area for about 10 weeks, until shoots about 2 inches long have formed on all the bulbs.
  4. Move the pot to a sunny location. Flower buds should appear within 2 to 3 weeks.

Varieties of Grape Hyacinth

Grape hyacinths offer many twists on the traditional deep blue cluster form. Look for unusual or heirloom varieties in bulb specialty catalogs. Because grape hyacinth bulbs are inexpensive, it pays to buy larger premium bulbs. These large bulbs will produce four or five flower stalks per bulb, as compared to two or three flower stalks produced by bargain bulbs. Don't worry that these large bulbs will sound the dinner bell to pests; hyacinth bulbs are rarely bothered by rodents.

  • 'Album': Pure white variety pairs well with blue grape hyacinth
  • 'Blue Magic': A fragrant, periwinkle-blue heirloom
  • 'Feather Hyacinth': Cheerful frizzy masses of purple petals
  • 'Golden Fragrance': Loosely grouped yellow florets with purple-tinged caps
  • 'Mount Hood': A bicolor type, vivid blue with a white cap
  • 'Ocean Magic': Dark blue flower base gradually fades to white caps
  • 'Tassel': A heirloom that features the standard cluster shape topped with a perky purple spray
  • 'Valerie Finnis': Otherworldly pale blue hue that seems to glow
Valerie Finnis Grape Hyacinth
'Valerie Finnis' Grape Hyacinth. James A. Guilliam/Getty Images 
Grape Hyacinth 'Mount Hood'
Grape Hyacinth 'Mount Hood'. Anne Green-Armytage/Getty Images 

Landscape Uses

Like most small flowering bulbs, grape hyacinths look best when planted in large quantities. Start with a grouping of at least 25 for a small garden or container. In an average-sized suburban garden, plant drifts of at least 100 in the flower garden or scattered beneath trees and shrubs.

  • An ambitious, but stunning grape hyacinth planting is to install the bulbs in a meandering serpentine pattern. Closely planting these low-growing blue flowers in this way mimics a river or stream in your landscape.
  • Bees are mad about the little blue flowers. Use this to your benefit by planting them near early blooming fruit trees that need pollination.
  • Grape hyacinth bulbs also work well in rock gardens. They don’t mind high altitudes, a full day of harsh sun, or dry conditions.
  • Create a layered look by underplanting daffodils with muscari bulbs. Plant about five muscari bulbs for every daffodil.