Muscari

( muss - KAIR - ee )

At-A-Glance Information

This genus of perennials grows from bulb and are commonly called Grape Hyacinths. They require full sun to light shade and regular water during their growth and bloom period to perform well in the landscape. They are native to the Mediterranean and southwestern Asia, and form grassy clumps of foliage from which spikes of blue or white sometimes fragrant flowers bloom for 3-4 weeks in early springtime. These spikes resemble bunches of Grapes, giving these plants their common name. Use Grape Hyacinth in rock gardens, mixed beds and borders, to fill in under trees and shrubs, and as underplanting for taller bulbs such as Tulipa and Narcissus.

Muscari Species and Varietals

The genus Muscari is a member of the plant family Asparagaceae and includes between 40 and 60 species. The plants in this genus are related to Scilla (Squill) and Hyacinthus (Hyacinth). The best growing zones for Muscari vary depending on the species; for more information, see the descriptions below. To find your zone, click here: Zone Map.

Muscari armeniacum (Grape Hyacinth, Armenian Grape Hyacinth, Garden Grape-Hyacinth)
This species of Grape Hyacinth grows best in USDA hardiness zones 3-9 or Sunset growing zones A2, A3 and 1-24. This plant typically produces bright blue flowers above floppy foliage, and has many varieties with differing flower colors and compositions. Grape Hyacinth is considered invasive in the south, east, and some western regions of the United States as well as Europe. Cultivars of this species are listed and described below:

'Blue Spike'
This species has double flowers in blue that form in a tight cluster.

'Cantab'
Light blue blossoms on a more compact, neat plant.

'Early Giant'
An early-blooming variety with dark blue flowers edged in white.

'Peppermint'
With white flowers that age to light blue.

'Pink Sunrise'
This variety has pale pink flowers.

'Siberian Tiger'
With brilliant pure white blooms.

'Touch of Snow'
Bicolored white and blue-purple flower spikes.

Muscari aucheri (Muscari tubergenianum) (Aucher-Éloy Grape Hyacinth, Grape Hyacinth)
This species grows to 8 inches tall and is best in USDA hardiness zones 4-8 or Sunset growing zones A1-A3 and 1-24. Flowers on the bottom of the spike are bright blue and those towards the top are more pale blue to whitish. Foliage is green and strappy. Cultivars include 'White Magic' (with pale yellow flowers that mature to white with yellow tips), and 'Ocean Magic' (with white to pale blue flower spikes). This species of Grape Hyacinth is invasive in North America, Europe, and Asia.

Muscari azureum (Hyacinthella azurea, Hyacinthus azureus, Pseudomuscari azureum) (Azure Grape Hyacinth, Grape Hyacinth)
This species grows best in USDA hardiness zones 3-9 or Sunset growing zones 2-24 and flower spikes rise 8 inches tall and hold fragrant, sky blue blooms that are bell-shaped rather than urn-shaped. Cultivar 'Album' produces pure white flowers. This species of Grape Hyacinth is considered invasive in North America, Europe, and Asia.

Muscari boytryoides (Grape Hyacinth)
Best in USDA hardiness zones 4-9 or Sunset growing zones A1-A3 and 1-24, this species has medium blue flowers on 1 foot tall stems. Variety 'Album' has white flowers and 'Superstar' produces cornflower blue flowers tipped with white. This species is native to central and southeastern Europe, where they typically grow in open woodlands and mountain meadows. It is considered invasive in Tennessee. This species is considered invasive in much of the eastern southern, and western United States.

Muscari comosum (Leopoldia comosa) (Fringe Hyacinth, Tassel Hyacinth, Tassel Grape Hyacinth)
This species grows in USDA hardiness zones 4-8 or Sunset growing zones 1-24 and has loose clusters of greenish brown to bluish purple blooms. The variety 'Plumosum' (pictured; also called 'Monstrosum') has violet-blue to reddish-blue blooms. This species is considered invasive in the United States, Britain, Ireland, Australia, and New Zealand.

Muscari latifolium (Broad-Leaved Grape Hyacinth)
This species grows best in zones 1-24 and is very showy. Each bulb produces a two-tone flowering stem that reaches a foot tall. Flowers at the bottom of the spike are deep violet and those towards the top are a vivid blue. Hardy down to -4 degrees Fahrenheit. Cultivars include 'Grape Ice', with white flowers that fade to dark purple as they age.

Muscari macrocarpum (Yellow Grape Hyacinth, Golden Fragrance Grape Hyacinth)
Grown in USDA hardiness zones 5-9 or Sunset growing zones 5-9 and 14-24, this species has strappy grey-green leaves and 6-8 inch tall flowering stems. Blooms are soft yellow on the bottom of the flower spike and fade to brown/purple at the tip. The flowers have a sweet fragrance. and bloom best after being dormant over a hot, long summer season. Variety 'Golden Fragrance' (pictured) has golden-yellow flowers at the bottom of the bloom spike and purple ones towards the top. Yellow Grape Hyacinth is considered invasive in North America, Europe, and Asia.

Muscari neglectum (Starch Hyacinth, Common Grape Hyacinth)
This species is best in zones 1-24 and forms stems 6 inches tall, with dark blue-purple blossoms edged in white at the bottom of the flower spike and pale blue blooms above. Flowers are scented like laundry starch. These plants are native to temperate climates in Eurasia. Cultivars include 'Baby's Breath' (with greyish-light blue blooms), and 'Valerie Finnis' (with sky blue flowers that turn vivid blue with age). This species is considered invasive in much of the United States as well as central and western Europe.

Caring for Muscari

Take care when planting these flowers in the landscape, as they are considered to be invasive in some areas of North America, Europe, and Asia and it is not recommended to be grown near crop species. They are often grown in containers to control their spread. Grape Hyacinth can either be purchased as starts or bulbs from reputable nurseries or online sources or grown from seed. Space these plants three inches apart, and plant bulbs three inches deep with their pointed ends up. When choosing a space in the landscape for planting these flowers, make sure to consider the fact that they do spread relatively aggressively, especially in ideal growing conditions. Muscari prefers a place in the landscape that receives full sun to partial shade. They do very well planted under deciduous trees, where they can get enough light during their leafout and blooming seasons, but shelter during their dormancy. They appreciate well-draining soil that has a good sand content. They are not picky about soil pH. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Do not mulch Grape Hyacinths, as most mulching materials are often too thick and heavy for the small bulbs.

Water newly planted Grape Hyacinth regularly as they establish a strong root system. Once mature, they appreciate regular waterings during their active growth and blooming cycle, and drier conditions as the season progresses and flowers fade to avoid rotting out bulbs. As a general rule of thumb, they will need weekly waterings while they are active. These plants do not need to be fertilized, but an application of compost can be added to the soil each year in springtime to support nutrition and healthy soil structure. These flowers are considered easy to care for and do not need to be pruned. However, if gardeners would like to control spread, flower spikes can be deadheaded to discourage reseeding. Removing spikes before they go to seed also encourages larger blooms to form in the next season, as bulbs are not wasting energy creating seeds. The grassy foliage should be left on plants for as long as it stays green so that photosynthetic material continues to be supplied to the bulb. They will die back after flowers fade in early summertime. New foliage will appear in fall and should be left on the plant until flowers bloom again. These plants will need to be divided every once in a while if they are grown in a small space or in containers. For instructions on how to successfully divide Grape Hyacinth plants, see the Propagation section below. Muscari plants are long-lived perennials and can survive in the garden for a decade or longer. They will form clumps of bulbs over time through offsets, and will naturally regenerate each spring after dying back. Clumps can be divided, providing new flowers for the landscape indefinitely.

Growing Muscari in Containers
Grape Hyacinth spreads easily, and for this reason many gardeners will choose to grow them in containers. They do well in clay pots with large drainage holes in the bottom, which allow water to escape quickly so that the bulbs will not rot out. Use well-draining somewhat sandy potting mix, and ensure that good drainage is occurring before installing bulbs. Place bulbs 3 inches apart and 3 inches deep under the substrate surface with their pointed ends up. Water regularly during the active growth and blooming periods in springtime, and lessen waterings after flowers fade and again after foliage fades in summer. Plants may outgrow their containers during the growing season. If this happens, they tend to not grow well because their root space is constricted, and plants will need to be divided. For instructions on how to successfully divide Grape Hyacinth flowers, see the Propagation section below.

Growing Muscari Indoors
Grape Hyacinth can be grown in containers either indoors or outdoors. Choose a clay pot with large drainage holes on the bottom, and fill it with well-draining somewhat sandy potting mix. Because the temperatures indoors are typically higher than they are out in the garden, bulbs will need some treatment before they are planted to ensure that they bloom. Chill bulbs in the refrigerator (or a similar space that remains under 40 degrees Fahrenheit) for about 10 weeks about 22 to 24 weeks before you would like the bulbs to bloom. For bulbs to bloom in late January through March, start the process in September through October. Next, place the bulbs 3 inches apart and 3 inches deep under the substrate surface with their pointed ends up. Move the pot to a cool, dark area for an additional 10 weeks until green shoots emerge from the bulb and reach 2 inches tall. The pot can then be transferred to a sunny spot in the home, and flower buds should emerge within two to three weeks' time. Water regularly during the active growth and blooming periods in springtime, and lessen waterings after flowers fade and again after foliage fades in summer. Plants may outgrow their containers during the growing season. If this happens, they tend to not grow well because their root space is constricted, and plants will need to be divided. For instructions on how to successfully divide Grape Hyacinth flowers, see the Propagation section below.

Harvesting Muscari Flowers
Grape Hyacinth plants make excellent cut flowers, and have a delicate, sweet scent. Blooms are available in white, pink, lavender, blue, and yellow, and their structure adds a unique texture to cut arrangements. The species most typically used as a cut flower are Muscari armeniacum and Muscari latifolium. Flowers should be harvested when they are at their peak of growth in springtime. Use clean, sharp shears or snips to cut flower stems close to the base of the plant, and immediately place them in a bucket filled a few inches tall with cool water. They are popular in spring bouquets and Easter flower displays, and have a vase life of around a week.

Propagation

Muscari, or Grape Hyacinth, can be propagated either by division or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Grape Hyacinth flowers, follow the instructions below:

Propagating Muscari by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. In the springtime after flowers have finished blooming, locate the circular green seed pods which develop in their place. Remove these pods from the plant and open them to access the seeds. Place them on a paper towel and leave them to dry out a bit in a cool, dark area. They can then be cold-stratified to prepare for planting, or stored in an airtight container in a cool, dark place.
For Grape Hyacinth seeds to germinate, they will need to undergo a process called 'cold-stratification', which mimics the conditions in their native environments. To complete this treatment, place seeds in a sealable bag or other container filled with moistened sand or peat moss, and then place that container in the refrigerator or a similarly cool environment. Leave the container there for up to three months' time, and then remove seeds and get ready to sow them. They may have sprouts beginning to form.
In either late winter or early springtime, get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray on the surface of the soil. Cover them with a light layer of soil and water with your spray bottle to avoid dislodging the seeds. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 6-8 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Muscari by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the bulb(s). Once you have worked it up out of the ground, lay it out. Tap or brush off any dirt that comes up with the bulbs.
Start to investigate the bulbs with your fingers. Larger bulbs are best for division. Smaller bulbs can simply be replanted on their own. Gently pull the larger bulbs and their bulblets apart to separate them.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your bulbs 3 inches deep spaced 3 inches apart with their pointed ends up and water thoroughly.

Muscari plants produce three-winged seed capsules and will turn brown and open in late springtime.

Grape Hyacinth seeds are tiny, black and round.

Problems and Pests

Certain Muscari species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. These plants can be susceptible to developing issues with the following pests and diseases in the landscape: