Firmament Allium flowers
(Photo courtesy of NetPS Plant Finder)
Plant Height: 14 inches
Flower Height: 32 inches
Spread: 15 inches
Hardiness Zone: 5a
Other Names: Ornamental Onion, Flowering Onion
Bold purple globes producing large flowers with silvery anthers, that resemble an exploding firework; an excellent naturalizier that is also great in containers
Firmament Allium features bold balls of lightly-scented purple flowers with silver anthers at the ends of the stems from late spring to early summer. The flowers are excellent for cutting. Its sword-like leaves remain green in colour throughout the season.
Firmament Allium 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, and should only be pruned after flowering to avoid removing any of the current season's flowers. It is a good choice for attracting butterflies to your yard, but is not particularly attractive to deer who tend to leave it alone in favor of tastier treats. It has no significant negative characteristics.
Firmament Allium is recommended for the following landscape applications;
- Mass Planting
- General Garden Use
- Naturalizing And Woodland Gardens
- Container Planting
Planting & Growing
Firmament Allium will grow to be about 14 inches tall at maturity extending to 32 inches tall with the flowers, with a spread of 15 inches. 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! As this plant tends to go dormant in summer, it is best interplanted with late-season bloomers to hide the dying foliage.
This plant should only be grown in full sunlight. It does best in average to evenly moist conditions, but will not tolerate standing water. It is not particular as to soil type or pH, and is able to handle environmental salt. It is highly tolerant of urban pollution and will even thrive in inner city environments. This particular variety is an interspecific hybrid. It can be propagated by multiplication of the underground bulbs; however, as a cultivated variety, be aware that it may be subject to certain restrictions or prohibitions on propagation.
Firmament Allium 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.
Disclaimer - This resource is provided for informational purposes only and does NOT reflect current availability. Inventory varies seasonally, so we cannot guarantee that every plant will be in stock at all times - please contact your favourite GardenWorks location directly for current availability. It does not include our entire inventory of plants, so be sure to visit GardenWorks to see varieties that may not be represented on this list.