Grape hyacinths (also known as muscari) are small spring-blooming bulbs, so named because of their 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 all have flowering umbels that emerge from a central stalk.
Native to Europe and Asia, grape hyacinths are workhorses that can light up the early spring flower garden for years with little to no care. Best planted in fall, grape hyacinths will grow slowly, emerging and blooming the following April or May, and lasting for about three weeks.
Many varieties of grape hyacinths display that rare crystal blue color so many gardeners covet, but they have none of the fussiness that some other 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|
|Mature Size||6–9 in. tall, 3–6 in. wide|
|Sun Exposure||Full sun, partial shade|
|Soil Type||Moist but well-drained|
|Soil pH||Neutral to acidic|
|Bloom Time||Early spring|
|Flower Color||Blue, white, lavender, pink, yellow|
|Hardiness Zones||4–8 (USDA)|
Grape Hyacinth Care
Grape hyacinths may be petite, but what they lack in size, they make up for in beauty and ease of care. Largely, you can plant grape hyacinths in the fall and forget about them for months until they emerge from the ground and enliven an otherwise empty early-spring landscape.
After your grape hyacinths are finished blooming, they'll 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 flowers. You can also shear the foliage when it starts to yellow.
Unlike many spring-blooming bulbs, grape hyacinths also produce a flush of grass-like foliage late in the summer or early fall. 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.
Grape hyacinth does best in full sun but tolerates partial shade. Keep in mind that many sites that are shady throughout the summer are actually quite sunny in the spring before nearby trees have leafed out. These are ideal areas for planting grape hyacinths, as well as many other spring bulbs.
For the best results, plant grape hyacinth in any well-drained soil around your property. Grape hyacinths are most fond of somewhat sandy soil, but they do well in pretty much all but the soggiest blends. Additionally, grape hyacinth is not at all picky about soil's pH level.
Grape hyacinths like a fair amount of moisture during the spring, but their soil should be allowed to dry out a bit as the season progresses. This helps to prevent bulb rot issues throughout the months that they're not in bloom.
Temperature and Humidity
Grape hyacinths do nicely in all climate conditions within their USDA hardiness zone range. However, they do require a cool winter period in order to bloom, so unseasonably warm winter temperatures may cause bloom failure the following spring.
No fertilizer is necessary for healthy grape hyacinth, but they may benefit from sprinkling 1/4 cup of bone meal (per 100 square feet of soil) once each year in the fall.
Grape Hyacinth Varieties
Grape hyacinths offer many twists on the traditional deep blue cluster form, and you can look for unusual or heirloom varieties in specialty bulb catalogs. Because grape hyacinth bulbs are inexpensive, it pays to buy larger, more premium bulbs. They'll produce four or five flower stalks per bulb, as compared to two or three flower stalks produced by bargain bulbs. Some common varietals include:
- 'Album': A pure white varietal that pairs well with blue grape hyacinth
- 'Blue Magic': A fragrant, periwinkle-blue heirloom varietal
- 'Feather Hyacinth': A varietal that boasts frizzy masses of purple petals
- 'Mount Hood': A bicolor varietal, with a vivid blue body and white cap
Growing Grape Hyacinth From Bulbs
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. Grape hyacinth bulbs form ever-enlarging colonies over the years, but the plants are not invasive.
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. In an average-sized suburban garden, plant drifts of at least 100 in the flower garden or scattered beneath trees and shrubs.
Potting and Repotting Grape Hyacinth
Another option is to buy enough grape hyacinth bulbs to force some for indoor flowering in containers. The bulbs will need about 10 weeks of chilling (at temperatures at least as low as 40 degrees Fahrenheit) to prepare them for blooming, so the refrigerator is a perfect place to store your grape hyacinth. Time the beginning of the chill period for about 22 to 24 weeks before you want the bulbs to bloom.
For blooms in late January through March, chill the bulbs for about 10 weeks in September through October. After chilling, plant 12 to 15 bulbs in a bulb pan or other container that's 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.
Move the pot to a cool, dark area for about 10 weeks, until shoots about 2 inches long have formed on all the bulbs. At that point, you can transfer the pot to a sunnier location, and flower buds should appear within two to three weeks.
Common Pests and Diseases
Grape hyacinth may have to contend with a variety of pests and diseases, some more serious than others. Common culprits like aphids and spider mites are typical, though they'll rarely become prominent enough to be considered an "infestation." If you notice these pests on your plants, you can try loosening them from the plan using a strong garden hose.
More serious are bouts of yellow mosaic virus, which is often characterized by a green pattern on the leaves, shortened stalk, or trouble growing. These diseases are typically spread by spider mites that infect the bulb, which is why they should be taken care of immediately if spotted on the plant. Unfortunately, yellow mosaic likely means the infected bulb won't survive, and any afflicted plants should be dug up and burned so the infection doesn't spread.