Allium Neapolitanum And Its Relatives
Allium Neapolitanum, which is often referred to as the Naples Onion, or the Star Of Bethlehem, and goes by a number of other names as well, is a member of the allium genus, a huge genus, consisting of many different species. It's commonly believed that not all of the species of allium have yet been discovered or classified. Many species, certainly most species, grow wild. Others are grown as ornamental plants, and yet others, such as leeks, onion, and garlic, are found in vegetable gardens or grown commercially for food. Allium species range from the Giant Allium with its blooming heads reaching nearly a foot across, to many small species, some of which are quite invasive.
Like many members of the Allium genus, Allium Neapolitanum grows from bulbs. It is hardy only in USDA Zones 7 and above, and is found primarily in California, Texas, Louisiana, and Florida, though it can be grown in pots elsewhere. Allium Neapolitanum attains a height of between 12 and 18 inches. The flowers are white, and somewhat delicate, branching out from the stem in a globe-like pattern. This allium species will grow in most soils and is somewhat drought tolerant. It is primarily propagated from bulbs and bulb offsets, but can also be grown from seeds, which may be collected once the blossoms have died back. The Allium Neapolitanum plant is native to Southern Europe, including Italy (Naples) and also native to North Africa.
This ornamental onion is often grown as a border plant and in rock gardens. When bulbs are set out about 4 inches apart it can serve as a ground cover, but this should be in places where there is no foot traffic! Bulbs are usually planted in the fall, and to a depth of 5 inches. In spite of its drought tolerant nature, the plant should have adequate moisture during its growing season. The plant is generally disease and pest free. The blooming period may vary somewhat depending upon location. But in general, allium plants are in bloom for about two weeks at most before the blossoms begin to turn brown. Most species only bloom once during a growing season. To function as a true perennial, the plant requires a cool season, with temperatures dipping to just above freezing, sandwiched in between two warm seasons. A frost may not affect bulbs, which are several inches below the surface, but will usually kill the plant if any growth above the surface is affected.
Allium Neapolitanum is sometimes grown commercially for cut flowers. A variety, "Grandiflorum" is characterized by having larger blossoms and is generally considered superior as a cut flower,
The allium in general is easy to grow, and most varieties, though not Allium Neapolitanum, are quite hardy. Over time the plants tend to become somewhat crowded. They are then usually lifted from the ground and divided. When cut or bruised, most allium plants have the familiar onion odor. The blossoms on the other hand can be quite pleasantly fragrant. While most species grow from bulbs, a few grow from rhizomes and others from tuberous roots. There are several species which do not form bulbs or rhizomes at all, but are propagated either from seed or by leaf cuttings. All varieties and species are relatively easy to propagate.
Allium Neapolitanum may be forced indoors in a pot. If this species is not suitable for the climate you live in, there are so many species of allium, most of which have white blossoms, that to find an acceptable substitute may not be all that difficult. If you must have this species however, growing it in pots indoors or in a greenhouse may be the answer.