Dr. Leonard Perry, Extension Professor
University of Vermont
One of the best ways for gardeners to chase away the winter blues is with the blue grape hyacinths. A spring flowering bulb, it is planted in the fall. Although considered a “minor” bulb, being shorter and less common than daffodils and tulips for instance, it contrasts well with most other bulbs, and is striking when planted in masses.
Grape hyacinths are so named because their dense flower stalks, usually about 6 inches high, are comprised of many small flowers (florets) resembling grapes. Their scientific name (Muscari) comes from the Latin word for musk, referring to their slight scent. Depending on the species, they come from the Asia Minor region and all around the Mediterranean. While some selections were made in the last decade, the oldest in cultivation date back 400 years or more.
While there are over 40 species, generally less than 10 and their cultivars (cultivated varieties) are found in catalogs and stores. Grape hyacinths are related to other spring bulbs such as hyacinths, squill (Scilla), and striped squill (Puschkinia). Formerly in the lily family, these are now placed by botanists in either the hyacinth or asparagus families.
The various grape hyacinths generally are placed into one of 4 groups, with some botanists considering one or more of these as different genera. The Leopoldia group is one of these, with taller plants (8 to 12 inches high), and florets spaced less densely along the stems. Florets are urn-shaped, flower in late spring, and are in colors other than blue. One species (comosum ) commonly found in this group, the tassel hyacinth, is one of the oldest introductions dating back to 1596. It has dark purple florets, while the related ‘Plumosum’ feather hyacinth cultivar dating to 1612 has feathery plumes of reddish violet.
The Pseudomuscari group is another that some consider a separate genus, comprising species that are small, often pale to bright blue, and flowering in early spring. Florets of this group are an open urn shape. A more common species in this group (azureum) was introduced in 1859 from the alpine meadows of eastern Turkey.
The Muscarimia group has one of the oldest species (muscarimi), introduced to cultivation in 1554. It has soft yellow florets with amber edges, with lavender florets on top of the stalks. Native to dry, sunny, and hot hillsides of Turkey and surrounding regions, this species is less cold hardy (USDA zone 5) than most of its relatives. A related species (macrocarpum) in this group has yellow flowers that turn purple as they age, or in the cultivar ‘Golden Fragrance’ they are yellow with a purple top.
The fourth and most common group of grape hyacinths, often considered the “true” ones, are those grouped under Botryanthus. The namesake species (botryoides) comes originally from Italy, and while once the most common is now seldom seen. You may find a white version of this species, or the cultivar ‘Superstar’ with thick stems and periwinkle-blue florets edged with white. Other species of this group may have dark blackish-blue flowers (neglectum), bright blue with white edges on florets (aucheri) or its cultivar ‘Mount Hood’ (one of my favorites) which is cobalt blue with a white top, or deep violet-blue with a periwinkle-blue top (latifolium). The latter originally came in 1886 from open pine forests in northwest Turkey.
Perhaps the most common grape hyacinth species and its cultivars (armeniacum) are also in this latter group. These have florets that are either sterile, or closed tightly so they can’t be easily pollinated. This means that they often stay in bloom longer. ‘Cantab’ is shorter than the species and flowers later. ‘Cote d’Azur’, introduced in 1987, has a rich lobelia-blue color. ‘Blue Spike’ has double, cobalt-blue flowers. ‘Saffier’ has an unusual coloration– green flowers that mature to a dusky blue from the top down.
Then you may find cultivars not in any one group, likely hybrids of species, including a couple of common ones. ‘Dark Eyes’ has sapphire-blue flowers with white rims, coming from the Caucasus region in 1969. ‘Valerie Finnis’ with its lovely pale blue flowers came from a garden in England, and is named after the plantswoman who found it.
Grape hyacinths are easy to care for, simply needing full sun and a well-drained soil for best growth. They will tolerate part shade, and some soil acidity, but prefer a neutral to slightly alkaline soil. Mix in a small amount of bulb food or just compost when planting, and give some fertility in spring after bloom. As with other bulbs, depth of planting should be about twice their height– about 2 inches deep.
Unlike other bulbs, these begin growth in late summer, with the grass-like leaves remaining through the winter. In cold climates, particularly with insufficient snow cover, these leaves may get injured and look poor in spring but usually recover. Grape hyacinths grow well in USDA zones 4 through 8, often into zone 3 with good snow cover.
Grape hyacinths are most effective planted in masses, although small groups of 3 to 5 may be interplanted among other bulbs or among perennials such as primrose and low creeping phlox, or may be naturalized in open woodlands. If in masses, use natural swaths and curves rather than formal blocks or long rows. They are often used along walks and in rock gardens.