Tree Onion, Walking Onion
Allium cepa proliferum
Family: Alliaceae
What it is like
Allium cepa proliferum is a BULB growing to 1.2 m (4ft). See above for USDA hardiness. It is hardy to UK zone 5 and is not frost tender. 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 moist soil.
Height (m): 1.2
Where it is found
Not known in the wild.
Original habitat is obscure.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 5
The plant forms small bulbs at the top of the flowering stem, these can be eaten raw or cooked. They have a strong onion flavour and are often used as pickled onions or added to salads. As long as the bulbils are dried properly at harvest time, they store well. Bulb - raw or cooked. The bulb can be up to 4cm in diameter and has a strong onion flavour. Chopped into slices, it makes a good addition to salads and can also be used as a vegetable or as a flavouring in cooked foods. Leaves - raw or cooked. A strong onion flavour, it makes a nice flavouring in salads though it should not be harvested in quantity because this would reduce the yield of bulbils. The leaves are produced from late autumn, though we have found that harvesting them at this time will often encourage diseases such as mildew.
Root: includes bulbs, corms, tubers, rhizomes etc.
Medicine
Rating: 3
Although rarely used specifically as a medicinal herb, the onion has a wide range of beneficial actions on the body and when eaten (especially raw) on a regular basis will promote the general health of the body. The bulb is anthelmintic, anti-inflammatory, antiseptic, antispasmodic, carminative, diuretic, expectorant, febrifuge, hypoglycaemic, hypotensive, lithontripic, stomachic and tonic. When used regularly in the diet it offsets tendencies towards angina, arteriosclerosis and heart attack. It is also useful in preventing oral infection and tooth decay. Baked onions can be used as a poultice to remove pus from sores. Fresh onion juice is a very useful first aid treatment for bee and wasp stings, bites, grazes or fungal skin complaints. When warmed the juice can be dropped into the ear to treat earache. It also aids the formation of scar tissue on wounds, thus speeding up the healing process, and has been used as a cosmetic to remove freckles.
Anthelmintic: Expels parasites from the gut.
Antiinflammatory: Reduces inflammation of joints, injuries etc.
Antiseptic: Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of micro-organisms.
Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.
Carminative: Reduces flatulence and expels gas from the intestines.
Diuretic: Acts on the kidneys, promoting the flow of urine.
Expectorant: Clears phlegm from the chest by inducing coughing.
Febrifuge: Reduces fevers.
Hypoglycaemic: Reduces the levels of sugar in the blood.
Hypotensive: Reduces blood pressure, it is used in the treatment of high blood pressure
Lithontripic: Removes stones from the kidney, bladder etc.
Skin: Plants used in miscellaneous treatments for the skin.
Stomachic: Aids and improves the action of the stomach.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Other
Rating: 3
The juice of the plant is used as a moth repellent and can also be rubbed onto the skin to repel insects. The plant juice can be used as a rust preventative on metals and as a polish for copper and glass. A yellow-brown dye is obtained from the skins of the bulbs. Onion juice rubbed into the skin is said to promote the growth of hair and to be a remedy for baldness. It is also used as a cosmetic to get rid of freckles. The growing plant is said to repel insects and moles. A spray made by pouring enough boiling water to cover 1kg of chopped unpeeled onions is said to increase the resistance of other plants to diseases and parasites.
Cosmetic: Used to improve the physical appearence of a person.
Dye: Plants that provide dyes.
Hair: Plants used as hair shampoos, tonics, to treat balding etc.
Polish: Plants used to give a shine to metals, wood etc.
Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.
Rust: Plants that can be used to prevent or treat rust.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
How it is grown
Prefers a sunny position in a light well-drained soil but succeeds in most soils that are in good condition. Tolerates a pH in the range 4.5 to 8.3. The bulbs should be planted fairly deeply. Some modern works have moved this plant from A. cepa, seeing it as being of hybrid origin with A. fistulosum and therefore renaming in A. x proliferum. The tree onion is a genuinely perennial form of A. cepa that is sometimes grown in the herb garden for its edible bulbils. Plants rarely if ever produce seed, instead the flowering head is comprised of a number of small onions or bulbils. Plants are propagated by means of these bulbils or by dividing the main bulb that grows underground. By no means a heavily productive plant, though the bulbils are very well flavoured and the plant is fairly easily grown. Its main problem is that slugs seem to be attracted to it and can eat to death even well-established 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. Said to be immune to onion root fly. Members of this genus are rarely if ever troubled by browsing deer. The plant is heat tolerant in zones 12 through 2. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of "heat days" experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is a clumper with limited spread. The root pattern is a bulb.
Propagating it: Harvest bulbils in late summer and replant immediately or store them in a cool dry frost-free place and plant them out in late winter or early spring. Division of the bulbs after the leaves die down in late summer.
Best place to grow: Cultivated Beds;
Habit: Bulb
Hardiness: 4-8
Growth:
Soil: Light (sandy), medium
Shade: No shade
Moisture: Moist
Things to keep in mind
There have been cases of poisoning caused by the consumption, in large quantities and by some mammals, of this plant. Dogs seem to be particularly susceptible.
Its other names
Local names
Tree onion, Topsetting onions, Walking onions, or Egyptian onions.