Ornamental onions: miracle balls for the perennial bed
In late spring, the ornamental onion blooms in full bloom. Viewed individually, the spherical blossoms are impressive, and in a flowerbed, this cluster of bulbs creates stunning plant images.
Ball season opens in the perennial bed
Hard to believe – the close relatives of onions, garlic, and chives are exceptionally "beet-friendly." The genus Allium is not only culinary, but also boasts decorative allium species and varieties. As spring gradually transitions into early summer,Perennial bedTheir dazzling appearance. Their plump flower globes on tall, sturdy stems, towering above most perennials, appear to float in the flowerbed. The ever-growing selection also includes smaller, low-growing, or extravagant varieties. The color palette of this chic bulbous flower ranges from white and pale pink to deep violet, blue, or red, and, depending on the variety, even with a metallic shimmer.
Of giants, curiosities and little drummers
Particularly impressive is theGiant leek(Allium giganteum). Its name says it all. Its flower stalks, unrivaled, reach up to 150 cm in height. Its compact, clear-violet flower balls measure an impressive 12 cm in diameter, just like those of its big brother, Allium 'Gladiator'. Such a dreamy bloom is topped by 'Globemaster', which forms enormous, aster-violet flower umbels measuring 25 cm in diameter on sturdy, 80-100 cm tall stems. This vigorous hybrid even surpasses its parents – Allium christophii and Allium macleanii. A true king among large-flowered ornamental onion varieties, it blooms in June.
With a flower size of 20 cm, the 60-80 cm highStar-shaped onion(Allium christophii) is also an absolute eye-catcher in the flowerbed. The metallic sheen of its star-shaped individual flowers in the rather delicate umbel is particularly captivating. This ornamental onion also boasts a very long flowering period. And it can be even more extravagant. Allium schubertii, alsoSchubert's ornamental onionA. schubertii, an ornamental onion with 30 cm flowers, cannot be left out of this list of giants. The purple and pink individual blossoms open on flower stalks of varying lengths, creating a snapshot of a firework. Unfortunately, this fantastic ornamental onion is not entirely winter hardy in our area. It is best grown in pots that can also be overwintered. A. schubertii is also an absolute hit as a cut flower. A single bloom and the vase is filled!
With its reddish-green, nodding flower bells, the Bulgarian leek is a bit of an oddity. A charming curiosity for plant lovers.
Nectaroscordon siculum is even more curious. The 90 cm highHoney garlicorBulgarian leek, which was formerly also called Allium bulgaricum, surprises with nodding, green-pink bell flowers that open from pointed buds and produce plenty of nectar - hence the name of this beautiful structural plant.
There are also at least three great candidates for the pure white look. Allium 'Mont Blanc' and 'Mount Everest' provide bright, happy moments in the perennial border from May to June. Allium nigrum offers hemispherical flowers with a long blooming period.
In mixed grass borders, the small but very fineDrumstick leek(Allium sphaerocephalon) attracts attention. Delightful, egg-shaped, just 4 cm in diameter, flower heads surprise with their play of colors as they bloom, from green to burgundy. This ornamental allium doesn't bloom until August, making it a perfect addition to late summer borders of grasses, coneflowers, and sedum. A small late bloomer that's a must-have in any prairie or natural garden.
“Let the little ones go to the front…”
While the large ones in the middle of the bed attract attention, low ornamental onions at the edge of the bed attract attention. For example, the 25 cm highBluetongue garlic(Allium karataviense) with decorative, gray-green foliage and silvery, shimmering, pale purple flower globes. This species is ideal as an eye-catcher for the foreground of borders, where the long-lasting blue leaves remain for a long time. One of the few ornamental onions that doesn't need to hide its foliage! The blue-tongue onion (the variety 'Ivory Queen' has white flowers!) also cuts a fine figure in the rock garden. Another must-have for the rock garden is theGolden garlic(Allium moly). This charming little ornamental onion has—as its name suggests—golden-yellow, hemispherical inflorescences and gray-blue-green, healthy foliage. This prolific flowering species, also only 25 cm tall, is not only popular with gardeners, but is also swarmed by bees and butterflies.
How to make ornamental onions look great in the garden
The bicolored flower heads of Allium spaerocephalon resemble small drumsticks. Flowering in August, it's a charming late bloomer.
Ornamental onions and their ilk prefer fertile, permeable, and well-drained soil in full sun. The only exception is wild garlic (Allium ursinum), which, as a forest plant, prefers a partially shaded location. Tall ornamental onions provide real highlights in the perennial border during the rather sparsely flowering period between spring and summer. Planting them among the perennials cleverly conceals the somewhat unsightly, yellowing foliage of the ornamental onion, which already begins to bloom before it blooms. Be sure to let the leaves die back; do not cut them off!
The best time to plant onions is in autumn – October/November. Depending on the variety, allium bulbs are planted 10 to 20 cm deep. Otherwise, the general rule of thumb for bulbs applies: twice as deep as the bulb is tall. It's recommended to mix some compost or organic complete fertilizer into the soil when planting the bulbs. Since alliums don't tolerate winter wetness, gravel or coarse sand should be worked into the planting hole for drainage in heavy soils. To ensure that the ornamental onion continues to bloom profusely for many years after planting, give it a dose of organic complete fertilizer or slow-release fertilizer every one to two years at the beginning of leaf growth, raking it in around the plants.
TIP:Even after flowering, ornamental onions are not lacking in charm. The seed heads have decorative value—in the flowerbed or in dried bouquets—a lovely reminder of early summer and its spherical, flowering delights.
TEXT: Martina Raabe
