Affectionately known as ‘butterfly candy,’ Alliums add pops of color to your flowerbed, with hues ranging from stark whites to blues, pinks, and purples. Onions, garlic, and leeks are close relatives, however, Alliums are adored for their spectacular flowers rather than their culinary use. In addition to their visual appeal, these plants have a delightful punchy aroma. They provide an attraction for pollinators, and dried flower heads can serve as accent pieces.
Best Allium Bulbs for Your Garden
Undeniably, Alliums’ vast array infuses gardens with round, tangled, and exotic-looking flower heads, both small and large. Some popular Allium choices include Allium ‘Purple Sensation’, ‘Globemaster’, giganteum, stipitatum ‘Mount Everest,’ ‘Silver Spring,’ ‘Millenium,’ cristophii, schubertii, ‘Dready’, sphaerocephalon, and caeruleum, ranging in height from 35cm (14in) to a towering 1.8m (6ft) tall.
Optimal Planting Time for Allium Bulbs
Allium bulbs are best planted in mid to late autumn, simultaneously with spring-flowering daffodils and tulips due to their shared hardiness to cold winter conditions [1]. Placing them in a well-drained soil further ensures an optimal bloom in late spring to early summer with some varieties, such as Allium sphaerocephalon, flowering in late summer.
Where to Grow Your Alliums
Ideally, Alliums mostly thrive under full sun and well-drained soil conditions. Planting taller Alliums in a sheltered spot prevents stem damage from strong winds. Gardens with more shade can accommodate yellow-flowered Allium moly or purple-flowering chives (Allium schoenoprasum), which prefer light afternoon shade. The Allium sphaerocephalon flowers prominently stand out in prairie planting schemes and borders.
Propagation and Plant Care
Planting Allium bulbs in cold, waterlogged soil is not recommended as the bulbs may rot. Clear away weeds and dig over the soil before adding leaf mould or compost to improve the texture. Place the bulbs with roots facing downwards in a hole about four times the bulb’s depth and fill in the hole. Alliums planted in deep pots need an equal mixture of John Innes No.3 compost, multipurpose compost, and grit.
Alliums planted directly in the ground seldom require watering, but potted Alliums demand regular watering in springtime, being cautious not to waterlog the compost. Enrich the bulbs during flowering with general-purpose fertiliser, and protect new spring leaves against pests like slugs and snails. Dried flowerheads can be left to stand in the border as long as possible without deadheading unless desired for aesthetic reasons. In winter, pots should be moved to a sheltered spot.
Growing Allium Bulbs from Offsets
Many Allium bulbs produce offsets or small bulbs attached to the main bulb. They can be separated and planted directly or in small pots to mature over several years before blossoming. Lift finished flowering Alliums carefully with a garden fork to check for offsets.
Alert on Pests and Diseases
Ornamental Alliums are susceptible to onion white rot, downy mildew and Allium leaf miner, which can be controlled by good planting environment and practices.
Growing Alliums add lush colors and unique shapes to your garden. Knowing when, where, and how to plant and maintain them ensures they thrive, creating an envious garden space.
