Giant Onion, Ornamental Onion
Allium giganteum
Family: Alliaceae
What it is like
Bloom Color: Pink, Purple. Main Bloom Time: Early summer, Late summer, Mid summer. Form: Upright or erect.
Allium giganteum is a BULB growing to 2 m (6ft) by 0.2 m (0ft 8in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 8. It is in flower in May. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, insects. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers dry or moist soil.
Height (m): 2
Where it is found
Not known
E. Asia - Afghanistan to Pakistan and north into Russia.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 3
Bulb - raw or cooked. We have seen no reports of edibility, but the bulb is certainly not poisonous and has a pleasant mild onion flavour. The fairly large bulbs are 4 - 6cm in diameter. Leaves - raw or cooked. Flowers - raw. Used as a garnish on salads.
Root: includes bulbs, corms, tubers, rhizomes etc.
Medicine
Rating: 2
Although no specific mention of medicinal uses has been seen for this species, members of this genus are in general very healthy additions to the diet. They contain sulphur compounds (which give them their onion flavour) and when added to the diet on a regular basis they help reduce blood cholesterol levels, act as a tonic to the digestive system and also tonify the circulatory system.
Other
Rating:
The juice of the plant is used as a moth repellent. The whole plant is said to repel insects and moles.
Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.
How it is grown
Landscape Uses:Container, Foundation, Massing, Rock garden, Specimen. Prefers a hot, sunny position in a light well-drained soil, it grows well in the light shade of thinly-clad shrubs that also like hot dry conditions. The bulbs tend to rot when grown in cool wet climates, even if they are given sharp drainage. One report says that this species is only hardy to zone 8, which only covers the mildest areas of Britain, whilst another says that it is much hardier and will succeed in zone 4. It is being grown successfully about 60 kilometres west of London, and so should be hardy at least in the south of Britain. The bulbs should be planted fairly deeply. Most members of this genus are intolerant of competition from other growing plants. Grows well with most plants, especially roses, carrots, beet and chamomile, but it inhibits the growth of legumes. This plant is a bad companion for alfalfa, each species negatively affecting the other. Members of this genus are rarely if ever troubled by browsing deer. Special Features: Attractive foliage, Fragrant foliage, Not North American native, Attracts butterflies, Suitable for cut flowers, Suitable for dried flowers.
Propagating it: Seed - sow spring in a cold frame. Prick out the seedlings into individual pots when they are large enough to handle - if you want to produce clumps more quickly then put three plants in each pot. Grow them on in the greenhouse for at least their first winter and plant them out into their permanent positions in spring once they are growing vigorously and are large enough. Division in spring. The plants divide successfully at any time in the growing season, pot up the divisions in a cold frame or greenhouse until they are growing well and then plant them out into their permanent positions.
Best place to grow: Cultivated Beds;
Habit: Bulb
Hardiness: 6-10
Growth: Fast
Soil: Light (sandy), medium
Shade: No shade
Moisture: Dry, moist
Things to keep in mind
Although no individual reports regarding this species have been seen, there have been cases of poisoning caused by the consumption, in large quantities and by some mammals, of certain members of this genus. Dogs seem to be particularly susceptible.