Alliums are members of the onion family. Cut a stem or crush a leaf and the connection is obvious! In the garden, these globe-like flowers have a look that’s both regal and playful.
An allium flower head is a cluster of individual florets and the overall shape may be round, oval or cascading. Colors include white, yellow, pink, purple and blue, and heights vary by species, ranging from just 5" to 4 feet tall. Each type of allium adds its own distinctive style and personality to the garden.
Most alliums bloom in late spring and early summer, helping to the gap between spring-flowering bulbs and summer perennials. For a chart that shows bloom times for different types of alliums, check out our Planning Guide for Alliums.
When you compare two allium bulbs side by side, it’s easy to see differences in quality. The larger the bulb, the more food energy is stored inside. Larger bulbs (as shown at far left) will produce stronger plants with bigger flowers. Longfield Gardens provides top size allium bulbs, so you can always enjoy the biggest, brightest blooms.
To see our complete selection of allium bulbs click HERE.
Sun or Shade: Alliums grow best in full sun, though most types will also tolerate partial shade.
Hardiness Zone: The bulbs are winter hardy in zones 3-8. To find your growing zone, refer to the USDA Hardiness Zone Map here.
Soil Conditions: Like most other bulbs, alliums need well-drained soil and should not be planted in a soggy area.
Perennial Gardens: Most alliums bloom in late spring, along with the last tulips and before irises and peonies. The flowers last for weeks and seem to hover over the garden like balloons. After flowering, both flowers and foliage fade away and allow summer perennials to take center stage. Some of the best alliums for perennial gardens include Gladiator, Globemaster, Purple Sensation and Allium christophii.
Rock Gardens: Alliums are well-suited to rock gardens, where they thrive in the well-drained pockets between rocks. Choose species that are smaller in size, such as Allium flavum, Allium karataviense and Allium sikkimense.
Cutting Gardens: Alliums are excellent cut flowers. Their stiff stems are easy to arrange, and the flowers are very long lasting. Planting alliums in a cutting garden will ensure you always have a plentiful supply of flowers for bouquets. Choosing several different types will give you flowers throughout the season. Good options include Purple Sensation, Allium atropurpureum, Mount Everest, Allium sphaerocephalon and Allium tuberosum.
Containers: Many alliums grow well in containers, either planted alone or mixed with in other plants. When they come into bloom, you can move the planter to a prominent spot where they’re easy to admire.
When to Plant: Allium bulbs are planted in the fall, after the first frost and before the ground freezes. Herbaceous alliums (such as Allium tuberosum and Allium Millenium) have a root ball like other perennials. These may be planted at any time during the growing season.
Depth and Spacing: Bulb size determines planting depth. Large bulbs such as Globemaster should be planted 6” deep, while smaller bulbs like drumstick alliums are only planted 3 or 4” deep. For best results, follow plant-specific instructions on the package or on our website.
Planting Tips: With alliums, there’s no need to worry about deer, squirrels or voles. They don’t like the onion taste of allium bulbs and almost always leave them alone.
To watch our planting video, click HERE.
Alliums usually produce leaves before they send up the first flower buds. For some species, this means the foliage starts to yellow and die back before the flowers have finished blooming. To help hide this fading foliage, plant the bulbs among plants that will cover the dying leaves. Good companions for alliums include hosta, astilbe, perennial geranium and lavender.
Expect to see lots of pollinators when your alliums are in bloom. These bulbs are an excellent addition to any sort of habitat garden.
Like their vegetable garden relatives, alliums are rarely troubled by pests or disease. Deer and pesky rodents aren't interested.
Most alliums are perennials. If the species you are planting is winter hardy and the bulbs are well-suited to the growing conditions in your yard, they will usually return to bloom again.
When alliums have finished flowering, their flower heads may be removed or left in place. The spent flower heads can be very ornamental, but if the heads remain and the seeds are allowed to mature, they will fall down into the soil below. Not all alliums are prolific seeders, but some are. If you want to avoid reseeding, remove the seed heads after flowering, before they can mature and release their seeds.
Alliums that grow from bulbs use their foliage to produce energy for next year’s flowers. It’s important to allow the foliage to die back naturally. Once it has withered, it can be removed with a gentle tug. When herbaceous alliums have finished blooming, use scissors or hedge shears to trim off the spent flowers. This will keep the plants looking neat and may encourage a second flush of flowers.
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