Allium validum aka Swamp Onion

Allium validum is known as swamp onion or Pacific onion. It belongs to the amaryllis family, Amaryllidaceae. Its native range runs from southwest Canada through the western United States. Records include British Columbia, Washington, Oregon, Idaho, California and Nevada. It grows in wet mountain meadows at middle and high elevations. This bulbous plant suits damp garden beds and bog gardens.

Plants reach about 2 feet (0.6 metres) in height. They form clusters of bulbs and thick, iris-like rhizomes. Each bulb can reach about 2 inches (0.05 metres) across. The leaves are edible, as are the bulbs and flowers. Flowers appear from July to August. Each flower has both male and female parts. Bees and other insects pollinate them. The supplied species evidence gives no flower colour or fruit details.

Choose a sunny site with light, well-drained soil. Sandy and loamy soils both suit this plant. It accepts mildly acid, neutral and mildly alkaline conditions. It needs ample water while growing and prefers moist or wet ground. It tolerates wetter soil than many other onions. Even so, damp soil that drains well is the safer garden choice. Plant the bulbs fairly deep. PFAF lists USDA zones 7–10 and cold tolerance near 14–23°F (−10 to −5°C). Alternating wet and cold winter spells can cause trouble without snow cover.

The bulbs can be eaten raw or cooked. Their flesh is somewhat fibrous but can flavour soups and stews. Eat the leaves raw or cooked, too. Raw flowers can serve as a salad garnish. PFAF gives this species an edible-use score of three out of five. It reports using the juice to deter moths. It also records claims that the whole plant deters insects and moles. These uses do not establish how well it controls pests.

Raise new plants from seed sown in a cold frame in spring. Move seedlings into pots when large enough to handle. Keep them under glass through at least their first winter. Plant them out in spring once they grow strongly. Division offers another way to increase plants in spring. Divisions can also succeed during the growing season. Keep them protected until they establish roots and resume growth. PFAF does not flag this species as weedy. It notes that the plant can hinder nearby legumes, including alfalfa.