Tips on how to develop decorative alliums

Allium bulbs, often known as decorative onions, throw up hanging spherical flower heads that create construction and drama from late spring to early summer season. Even when flowering is over, the engaging seedheads proceed to lend fascinating texture to your planting show. We requested skilled gardener Carol Bartlett for her recommendation on rising decorative alliums. Listed here are her tried and examined suggestions…

Browse our full vary of allium bulbs for inspiration.

Greatest allium bulbs for beds, borders and containers

No early summer season border is full with out the stand-out purple blooms of the allium flower. They add construction, peak and hanging layers of color with big flower heads that frequently span 15cm throughout. Tall varieties resembling allium ‘Globemaster’ can attain 80cm excessive whereas ‘Purple Sensation’ grows to 100cm.

One in every of my favorite varieties is allium ‘Christophii’ with its massive, mauve, sparkler-like heads made up of tiny stars. This barely shorter allium grows to round 60cm, and the architectural define of the flower heads continues to look nice as they fade. Comparable in peak, however much more uncommon trying, allium ‘schubertii’ has dozens of tiny mauve flowers spiralling out from the centre to present it a dramatic look. Flowering from March till the top of Could, it’s preferrred for containers.

One other good container selection is allium amplectens ‘Swish Magnificence’ which reaches round 30cm tall and has massive white flowers with a fragile contact of pink. Though mauve is the standard color of alliums – from gentle lilac to wealthy purple – the vary extends to blue, white and even yellow. Allium caeruleum ‘Blue Drumstick’ is a compact blue selection that works nicely in pots.

All alliums are engaging to bees, however none extra so than allium schoenoprasum (generally generally known as chives). Only a small clump of those edible ornamentals acts as a bee magnet! All chives are low-growing, preferrred for fronts of borders, rockeries, small containers and mixing within the herb backyard. When you minimize them again throughout the summer season you’ll be rewarded with a second flush of foliage and flowers.

And for late-summer and autumn color, plant allium ‘sphaerocephalon’. This tall selection with darkish purple flower heads seems to be particularly good alongside late-flowering perennials like crocosmia ‘lucifer’ and autumn grasses like Stipa tenuissima.

The place to plant decorative alliums

Also referred to as Star of Persia, Allium christophii produces flower heads as much as 20cm throughout
Picture: Allium christophii from Suttons

All alliums have related rising necessities. They like full solar (ideally round 6 hours) and well-drained soil with no winter moist. Alliums are absolutely hardy, but when planted in moist soil the bulbs might rot and fail to return the next 12 months.

For one of the best outcomes, alliums must be planted in teams quite than noticed round. I like to recommend planting them in teams of three, 5 or 7 and repeating these teams in two or three locations across the backyard. It’s tempting to place taller alliums behind a border, however this may look a bit contrived and I want to combine up the planting.

The one draw back to rising alliums is that the foliage can look frayed early within the rising season. To beat this, develop them amongst foliage companion vegetation that present loads of cowl. Alchemilla mollis is an effective selection – the abundance of foliage and frothy lime inexperienced flowers distinction nicely with alliums’ purple flower heads. Hostas are one other good companion.

For taller alliums, the intense inexperienced foliage and yellow bracts of euphorbia palustris supply an fascinating distinction. Pink and orange types of Geum additionally make good companions.

Tips on how to plant allium bulbs

This compact selection is nice for the entrance of borders and patio containers
Picture: Allium amplectens ‘Swish Magnificence’ from Suttons

The perfect time of 12 months to plant allium bulbs is autumn – particularly September and October. A superb rule of thumb for planting any bulbs, together with alliums, is to plant them at 3 x the depth of the scale of the bulb. Naturally which means that smaller allium bulbs, like chives, will probably be just a few centimetres deep whereas the massive globemaster bulbs, which might be as massive as 20cm, will probably be planted at the very least 60cm deep. It’s vital to not plant allium bulbs too shallow, because the depth helps to anchor the bulb towards gusty wind.

House your bulbs 10-20cm aside, relying on their dimension. Greater bulbs want extra space to permit the bulb to develop and produce a big flower head.

Tips on how to look after decorative alliums

These magnificent lilac blooms add the ‘wow’ issue to borders and vases
Picture: Allium ‘Globemaster’ from Suttons

One of many advantages of rising alliums is that, as soon as planted in the best place, they are going to develop unattended and maintenance-free for a few years. While the bulbs dislike winter moist, the upside is that they’re drought-tolerant. I’ve by no means needed to water my alliums. Even when there’s a summer season drought, it’s normally adopted by some autumn rains to compensate. Equally, if alliums are rising on cheap soil it’s not essential to feed them. Solely feed these which are rising in skinny or poor soil.

In case your alliums turn into congested, you may wish to divide them. The frequency will differ, relying on rising situations. In preferrred rising situations, the bulbs will multiply extra readily and might have dividing each 4-5 years. In much less beneficial situations, they are going to bulk up extra slowly. Division is simple. After the plant has completed flowering and the leaves have died again, dig up the clump and separate the bulbs into two or three sections earlier than replanting.

Avoiding frequent issues

These lovely allium heads look implausible en masse amongst grasses
Picture: Allium sphaerocephalon from Suttons

There are combined views on the necessity to stake alliums. The choice in all probability depends upon the variability you’re rising and the place within the nation you’re gardening. I like to recommend staking the taller varieties, particularly in case your backyard is susceptible to gusty winds.

Alliums are typically trouble-free, regardless of the lengthy listing of illnesses which may assault the onion household. Rust is the most typical drawback and you’ll spray towards it or, if gardening organically, merely take away contaminated foliage. The easiest way to keep away from rust is to not plant the bulbs too shut collectively.

To make sure alliums bloom nicely 12 months after 12 months, plant on the right depth. If the bulbs are too shallow, your alliums might not bloom. It’s additionally vital to go away the foliage in place so it dies down naturally. This permits the plant to photosynthesis and feed the bulb for the subsequent 12 months.

Planted on the proper depth and in the best place, you may benefit from the beautiful blooms of alliums 12 months after 12 months with minimal upkeep. The bees and butterflies will thanks too! Learn our information to rising spring bulbs for extra useful data.

Lead picture: Allium ‘Medusa’ from Suttons