Growing Allium Millenium (Ornamental Onion) 2018 Perennial Plant of the Year

In the world of alliums, few names stand out more than that of Mark McDonough.

Known for being the man behind some of the most popular allium hybrids and cultivars in the world, Mark’s 2000 contribution was a compact little gem called Allium ‘Millenium.’

Growing Allium MilleniumPin

This wonderful addition to the Amaryllidaceae family has a lot going for it.

Allium ‘Millenium’ Care

Size And Growth

Allium ‘Millenium’ is one of the smaller alliums out there, generally growing to about 20″ inches tall and around 15″ inches across.

However, that doesn’t mean this fast-growing plant doesn’t have character.

The thick, glossy green leaves are upright and strap-like in shape.

This compact foliage gives off a mild oniony scent when crushed.

Flowering And Fragrance

Unlike many other alliums, ‘Millenium’ is a relatively late bloomer, with its rounded flower clusters appearing in mid to late summer.

The 2″ inch umbels are actually hundreds of little pinkish-purple to blue flowers, and you’ll generally get 4 to 8 flower heads per plant.

Like many other alliums, the long-lasting flowers will dry out before they die, making them a popular choice for flower displays.

However, while these blooms are popular amongst both humans and pollinators, they’re actually sterile and won’t produce seeds.

Light And Temperature

As with most alliums, ‘Millenium’ prefers full sun but needs a little light to partial shade in the afternoon when grown in southern locations where the sun can be particularly harsh.

The plant could suffer from scorching if left exposed to the midday sun in arid or subtropical climates.

In fact, ‘Millenium’ grows best in USDA hardiness zones 5 to 9.

When properly insulated, growers have reported success as far north as zone 3.

Much like other alliums, it’s best to avoid too much heat in spring, as this can slightly wilt the stems and prevent them from being as sturdy as they need to be to support the umbels.

Watering And Feeding

As with most alliums, ‘Millenium’ needs very little water to thrive.

Using the soak and dry method, aim to water the plant when the soil feels dry, 1″ to 2″ inches down.

Even better, ‘Millenium’ is adapted to thrive in very poor conditions and doesn’t need to be fertilized.

Soil And Transplanting

You can plant Allium ‘Millenium’ in almost any soil type, which will do equally well.

Sandy and loamy soils are perfect, but you’ll need to add some coarse sand or perlite to clay soil to ensure good drainage.

Transplanting isn’t necessary for this plant, as the bulbs can overwinter in the ground.

Likewise, potted plants will only need to repot every couple of years to remove the mineral salts and other toxins.

However, it’s a popular habit to uproot ‘Millenium’ in the fall when its foliage dies back to divide the bulb.

Grooming And Maintenance

Very little maintenance is required for the Allium Millenium plant.

Many growers like to deadhead the spent blooms to prevent seeding, although this isn’t necessary.

You may also need to occasionally remove a diseased leaf or two on the rare occasion the plant gets sick.

How To Propagate ‘Millenium’?

Allium ‘Millenium’ can self-seed at a much lower rate than other hybrids.

However, there’s no guarantee you’ll get the same plant from its seeds.

As a result, the accepted method of propagating this plant is division in the fall.

Wait until the foliage has died before dividing, and add a protective layer of mulch if you’re in an area prone to frequent freeze and thaw cycles to prevent rot.

While not as common, it’s also possible to divide the bulbs in early spring.

Ornamental Onion Pests Or Diseases

Alliums are natural at pest repelling, making it extremely rare for an infestation of any sort to occur. 

They’re also resistant to deer, rabbits, and drought.

The only real disease problems are onion white rot and downy mildew, which are rare unless you overwater the plant.

Allium ‘Millenium’ Uses

‘Millenium’ is usually planted in the garden, but it works well in containers.

Place a potted specimen in a sunny window or add it to a hanging basket on your porch for a wonderful display.

Just be sure to bring container plants into a cool room such as the garage during winter, as the bulbs won’t be well insulated.

This plant attracts butterflies and other pollinators to your garden in addition to other beneficial insects while repelling pests, making this a perfect companion plant.

Add to that its relatively short size, and you have the perfect addition for borders and as a foreground plant for larger flowerbeds.

Published at Wed, 21 Sep 2022 06:21:00 -0400

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