Giant Allium, Allium giganteum

AKA Giant Onion

As a food item, light use is recommended for this species. As part of the allium (onions, garlic, leeks) genus, giant allium seem to be edible, but research on this is limited. Because of this, light use is recommended as food. But the ecological uses alone make them worth having in the garden and food forest.

Plant Common Name: Giant Allium
Botanical name: Allium giganteum

• Cold hardiness zones: 4a to 8b oai_citation:1,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Soil PH: Acid (<6.0), Neutral (6.0-8.0), Alkaline (>8.0) oai_citation:2,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Watering needs: Medium moisture, well-drained soils; drought tolerant but should be kept moist during the growing season oai_citation:3,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox oai_citation:4,Allium giganteum (Ornamental Onion) – Gardenia.
• Food forest layer: Typically used as a flowering plant in gardens, ideal for the herbaceous layer.
• Which parts of the plant are eaten as food: Leaves, bulbs, and bulblets are edible, but note the plant’s low toxicity oai_citation:5,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Blooming Season: Early summer, around June to July, lasting 2-3 weeks oai_citation:6,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Harvest season/regularity: Information on the specific harvest season and regularity is not detailed in available sources.
• Fruiting age: Not explicitly stated, but it is a perennial bulbous plant oai_citation:7,https://www.homefortheharvest.com/giant-allium/.
• Age of maturity (full size and peak fruiting): Leaves and scapes smell like onions when bruised, but plant is not used for culinary purposes. Leaves begin to die back as plants begin flowering oai_citation:8, Allium giganteum – Plant Finder .
• Average mature yield: Specific yield information is not readily available.
• Pollination for Fruit: Attracts bees, butterflies, and other pollinators oai_citation:9,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Size at maturity: Height: 1 ft. – 6 ft., Width: 1 ft. – 2 ft oai_citation:10,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox oai_citation:11,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Sun needs: Full sun (6 or more hours of direct sunlight a day) oai_citation:12,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Preferred habitat: Naturalized areas, cottage gardens, cutting gardens oai_citation:13,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox oai_citation:14,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Growth rate (vigor): Medium oai_citation:15,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Natural reproductive rate (and methods): By division and seed oai_citation:16,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Propagation method: Division and seed oai_citation:17,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Average life span: Not specifically stated, but it’s a perennial plant.
• Good companion plants: Does well with daylilies and low-growing grasses oai_citation:18,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Plant family: Amaryllidaceae oai_citation:19,Growing Allium Giganteum: Learn Giant Ornamental Onion Care.
• Taproot: Information not specifically available.
• Predators: Attracts butterflies; resistant to deer, rabbits, and drought oai_citation:20,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox oai_citation:21,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Other common problems/solutions: Susceptible to bulb mites, fungal issues, and black rot in overly damp conditions oai_citation:22,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox oai_citation:23,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.
• Cautions: Low severity poison characteristics, poisonous through ingestion. Symptoms may include nausea, vomiting, and diarrhea oai_citation:24,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox oai_citation:25,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.

Notes:

• Ecological functions/uses: Attracts pollinators; ornamental value; potential to be weedy in disturbed areas.
• Food uses: Leaves, bulbs, and bulblets are edible, with caution due to low toxicity.
• Food Flavor/Taste: Fragrance resembles garlic or onion oai_citation:26,Allium giganteum (Giant Ornamental Onion, Ornamental Onion) | North Carolina Extension Gardener Plant Toolbox.

Giant Allium offers both aesthetic and practical benefits for a permaculture garden, with its striking appearance and edible parts. However, care should be taken due to its low-level toxicity and susceptibility to certain pests and diseases.

Giant Allium Propagation

Propagating Giant Allium (Allium giganteum) can be achieved through various methods, including:

1. Division of Bulbs: This is a common method for propagating Giant Allium. In early to mid-autumn, after the flowers and leaves have died back, you can divide the bulbs. Using a trowel, carefully dig around the plants, maintaining a distance of about eight centimeters from the bulb clump. It’s advisable to select bulbs from different areas of your allium bed for division oai_citation:1,How to Propagate Allium Plant: Propogation Made Easy.
2. Growing from Seed: If your Giant Allium produces seeds, you can propagate them this way. It’s an easy and cost-effective method, especially for expanding the number of plants in your garden. However, note that not all ornamental alliums will produce seeds, and some may produce only a few. If available, seeds can be saved and sown oai_citation:2,How to grow alliums / RHS Gardening.
3. Stem Cuttings: Another method, though less commonly successful, involves using stem cuttings. In spring or early summer, cut a section of the stem about ten centimeters long from a healthy parent plant, ensuring a few leaves are attached. The cut end should be dipped in rooting hormone powder and then planted in well-draining soil oai_citation:3,How To Grow Allium From Seed- (Ornamental Allium).

For all these methods, ensure the plants are placed in well-drained soil and receive full sunlight, as Giant Allium thrives best under these conditions oai_citation:4,Error oai_citation:5,Growing Allium Giganteum: Learn Giant Ornamental Onion Care.

Each propagation method has its advantages and specific steps, so consider your garden’s conditions and your experience level when choosing the best method for your needs.