Plant Library

Other Names:  Autumn Onion

Description:

Pretty pink flower spheres rise on leafless stems from mid-summer to early fall; an excellent plant for attracting pollinators; this native selection looks beautiful massed borders, containers or as a rock garden accent; tolerant of hot and dry conditions

Ornamental Features

Prairie Onion features bold balls of lightly-scented lavender flowers with rose overtones and yellow anthers rising above the foliage from mid summer to early fall. The flowers are excellent for cutting. Its fragrant grassy leaves remain green in color throughout the season.

Landscape Attributes

Prairie Onion is an open herbaceous perennial with tall flower stalks held atop a low mound of foliage. Its relatively fine texture sets it apart from other garden plants with less refined foliage.

This is a relatively low maintenance plant. Trim off the flower heads after they fade and die to encourage more blooms late into the season. It is a good choice for attracting bees and butterflies to your yard, but is not particularly attractive to deer who tend to leave it alone in favor of tastier treats. Gardeners should be aware of the following characteristic(s) that may warrant special consideration;

• Self-Seeding

Prairie Onion is recommended for the following landscape applications;

• Accent
• Mass Planting
• Rock/Alpine Gardens
• General Garden Use
• Naturalizing And Woodland Gardens
• Container Planting

Planting & Growing

Prairie Onion will grow to be about 18 inches tall at maturity extending to 24 inches tall with the flowers, with a spread of 12 inches. When grown in masses or used as a bedding plant, individual plants should be spaced approximately 6 inches apart. It grows at a medium rate, and under ideal conditions can be expected to live for approximately 5 years. As an herbaceous perennial, this plant will usually die back to the crown each winter, and will regrow from the base each spring. Be careful not to disturb the crown in late winter when it may not be readily seen!

This plant does best in full sun to partial shade. It prefers dry to average moisture levels with very well-drained soil, and will often die in standing water. It is considered to be drought-tolerant, and thus makes an ideal choice for a low-water garden or xeriscape application. This plant does not require much in the way of fertilizing once established. It is not particular as to soil pH, but grows best in sandy soils. It is highly tolerant of urban pollution and will even thrive in inner city environments. This species is native to parts of North America. It can be propagated by multiplication of the underground bulbs.

Prairie Onion is a fine choice for the garden, but it is also a good selection for planting in outdoor pots and containers. With its upright habit of growth, it is best suited for use as a 'thriller' in the 'spiller-thriller-filler' container combination; plant it near the center of the pot, surrounded by smaller plants and those that spill over the edges. Note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.