Ornamental alliums, often called flowering onions, are popular additions to garden landscapes due to their unique, globe-shaped flowers and minimal care requirements. These hardy, bulbous perennials provide a striking architectural element to garden beds, blooming in late spring and early summer. Their colors are primarily in the purple, pink, and white spectrums. Successfully integrating these plants into your garden begins with knowing where to find the highest quality bulbs and understanding the characteristics of a healthy specimen. Selecting the right source and inspecting your purchase closely are the first steps toward enjoying their display year after year.
Identifying Reputable Sources for Allium Bulbs
The source of your bulbs affects the quality, variety selection, and ultimate success of your planting effort. Large online retailers and specialty bulb companies offer the most extensive selection of allium cultivars, including rare and newly developed varieties. These distributors often provide robust guarantees regarding bulb health and trueness to type, compensating for the inability to physically inspect the bulbs before purchase.
Mail-order catalogs are another excellent source, often catering to enthusiastic gardeners by featuring unique or heritage varieties not commonly found elsewhere. Purchasing directly from a dedicated bulb grower ensures you receive freshly harvested stock.
Local nurseries and garden centers provide the advantage of immediate inspection, allowing you to visually verify the condition of the bulbs before you buy. While their variety selection is typically smaller and focused on locally successful types, the staff can offer tailored advice for your specific growing conditions. Selecting a source that specializes in bulbs will generally yield superior quality compared to generic mass-market retailers.
Essential Considerations Before Purchasing
The timing of your purchase is closely tied to the ideal planting window, which is late summer through early fall, typically September to November, before the ground freezes solid. This timing allows the bulb to establish a root system before winter dormancy, which is necessary for a strong spring bloom.
When selecting individual bulbs, the most important characteristic is firmness, indicating a healthy, dormant state with ample stored energy. Avoid any bulbs that feel soft, mushy, or show visible signs of mold or rot, as these are unlikely to sprout successfully. Larger bulbs, often graded as “top size,” contain more stored nutrients and generally produce stronger plants with larger flowers in their first season compared to smaller grades.
Choosing the right variety requires considering the mature height, flower color, and bloom time to ensure they fit your garden design. Alliums range from diminutive types suited for rock gardens, such as Allium karataviense, to majestic four-foot giants like Allium giganteum or ‘Globemaster’. Selecting a mix of early, mid, and late-blooming varieties can extend the visual impact of the allium display well into the summer.
Ensuring Success After Purchase
If immediate planting is not possible upon receiving your allium bulbs, proper short-term storage is necessary to maintain their viability. Bulbs should be kept in a cool, dry, and well-ventilated location, such as a basement or garage, away from direct sunlight and extreme temperature fluctuations. Placing them in a breathable paper bag or mesh sack prevents moisture accumulation, which is the primary cause of rot.
For planting, choose a site that receives full sun, although alliums can tolerate partial shade, and ensure the soil is well-drained. Poor drainage is detrimental to allium health, causing the bulb to rot.
A general rule for planting depth is to bury the bulb two to three times its diameter, with the pointed end facing upward. Spacing requirements vary by size, but a general range of six to eight inches apart is suitable for most large-flowered varieties to allow for proper air circulation and growth. After placing the bulbs and covering them with soil, water the area thoroughly to settle the soil around the bulbs and initiate root growth. After this initial watering, alliums are drought-tolerant and typically require minimal supplemental watering.