Most likely, when you think of alliums, you picture those plants with the traditional round, purple flowerheads on long stalks that make borders look amazing in late spring and early summer. Alliums, however, are much more than this.
There are alliums that are white, pink, blue, and yellow. There are some alliums that resemble a fireworks display, and others that resemble knotted dreadlocks.
You can identify that alliums are related to onions, garlic, and leeks by the aroma released when you crush the foliage. This family also includes chives (Allium schoenoprasum), which have delicious leaves that may be sliced and used to salads and dips.
Alliums are a favorite of butterflies and bees, and even the dried flowerheads look lovely in the border or in floral arrangements.
When to plant allium bulbs
The greatest time to plant alliums is in mid- to late-autumn, at the same time as tulips and daffodils that bloom in the spring. Allium bulbs are resilient and can withstand harsh winter weather if they are planted in soil that drains effectively.
Some attractive alliums, like “Allium sphaerocephalon,” flower in the late summer. Most ornamental alliums bloom in the late spring and early summer.
Where to plant alliums
The majority of alliums thrive in full sun and well-drained soil. Tall alliums should be planted in a protected area to prevent the stems from blowing over in high winds. Plant purple-flowered chives (‘Allium schoenoprasum’), which appreciate afternoon shade, or yellow-flowered ‘Allium moly’ in shaded areas.
Tall alliums look great planted in broad swaths or punctuated across a border. Late-summer bloomer Allium sphaerocephalon has gorgeous wine-red flowers that stand out amid the grasses in prairie planting schemes.
Long, slender leaves on ornamental alliums fade back as the flowers emerge. To conceal the waning foliage, place allium bulbs under other low-growing plants.
Planting allium bulbs
- Remove any weeds by turning the dirt over. Dig in leaf mold or compost instead of using manure on heavy soil as this can change the soil’s pH level. Alliums thrive in soil with a pH that is neutral.
- Make a hole that is roughly four times the bulb’s depth.
- Put a bulb in the opening with the roots pointing down.
- Gently compact the earth after filling the hole.
Alliums can also be grown in large pots with soil that is a mixture of grit, John Innes No. 3 compost, and multipurpose compost.
Tips on caring for alliums
- Ground-planted alliums typically don’t require irrigation.
- In the spring, alliums grown in containers will require regular watering. However, avoid letting the compost become soggy as this could lead to the bulbs rotting.
- Crushed eggshells around plants, copper tape around pots, beer traps, or wildlife-friendly slug pellets can all be used to deter slugs and snails from eating new spring leaves.
- When the plants are in bloom, spread a general-purpose fertilizer to aid in the development of the bulbs, assuring healthy flowers the following year.
- Once the leaves have withered back, remove them.
- There is no need to deadhead the flowerheads unless you choose to because they still look excellent after flowering has completed. As long as they remain in place at the border, they may be ignored.
- Put pots in a greenhouse or up against a wall of a house in the winter to shield them from the cold weather.
Growing allium bulbs from offsets
Offsets, which are little bulbs affixed to the main bulb, are produced by many allium bulbs. These can either be planted directly in the ground or split from the main bulb and placed in tiny pots to grow on. Before they have developed enough to produce flowers, it will take a number of years.
Wait until the allium plants are through flowering before using a garden fork to carefully uproot the plants and inspect the bulbs for offsets. Replant the bulbs after removing any offsets.
Best allium bulbs to plant
Alliums come in a wide variety, from large to little, with flowerheads that are rounded or exotic-looking twisted. Here is a selection of the most well-liked alliums.
- One of the most well-known alliums, Allium ‘Purple Sensation’ has the traditional deep purple spherical flowerheads on long, robust stalks. 1 m (3.5 ft) high.
- Large circular purple flowerheads up to 15 cm (6 in) across on robust stems that are 80 cm (3 ft) tall characterize Allium ‘Globemaster’.
- As its name suggests, Allium giganteum is a true giant with dense, spherical purple flowerheads on stems up to 1.8 meters (6 feet) tall.
When can alliums be purchased?
At the fall, bulbs are abundantly available in garden centers and online. You have the opportunity to select the ideal flower kind for your garden when you purchase plants in bloom in the spring or early summer.
You can utilize RHS Find a Plant or go to a specialized nursery to locate specific varieties.
Where to plant
- Border alliums require a sheltered location (to prevent the flower spikes from being blown over) as well as free-draining soil and lots of sunlight for the greatest results.
- You can also grow allium in pots.
- Avoid planting bulbs in wet or cold conditions because they may decay.
- It is preferable to avoid planting the bulbs in frequently cultivated garden areas because digging can easily destroy the bulbs.
- It is better to grow alliums where their foliage is hidden by that of other plants because their leaves fall off when they begin to bloom. The leaves can be removed without harm when they begin to die back.
In borders
Early in the fall, bury bulbs at a depth that is roughly four times their diameter. Taller species require at least 20 cm (8 in) between the bulbs, while shorter species should be planted 7.5–10 cm (3–4 in) apart.
how do you dry alliums?
Pick off seedheads that are starting to fade and store them for a few months in a cold, dry place, such a shed or cellar. To use as Christmas decorations, I like to dry my seedheads and then spray-paint them silver.
are alliums edible?
Since they are all members of the allium family, onions, leeks, and garlic are often consumed foods. Alliums are theoretically edible, but beware eating any that are designed to be aesthetic garden plants because they may have been chemically treated.
are alliums good for bees?
In the spring, bees and other pollinators are all over our alliums. Our neighborhood beekeeper also claims that the honey doesn’t taste oniony.
do alliums need staking?
Even the tallest alliums won’t need staking since their sturdy stems can hold them if they are planted deeply enough in full sun (so they don’t extend toward the light) and in a sheltered location (so they don’t blow over in the wind).
Learn About Planting Allium Bulbs, The Graceful Globes Of The Garden
An decorative member of the onion family is the allium. The hundreds of tiny florets that make up their spherical flowers are particularly alluring to bees and other pollinating insects. When planted with lower-growing plants, they look amazing because blossoms develop at the apex of tall, slender stalks. Allium bulbs add form and color to any garden, so it’s understandable why more and more of us are planting them. Plant in a container with tulips or other springtime plants, or place a few in your beds and borders to create structure.
Planting Allium Bulbs: When To Plant Them
Alliums are among the easiest flower bulbs to grow because they tolerate most soil types and are hardy only to zone 4. Before the earth freezes, they should be planted in the fall between September and November. Since they actually love dry circumstances, watering them won’t be a problem very often. Pick a sunny location, give them some water when you plant them, and then watch for the beautiful blooms in late spring and early summer.
Planting Allium Bulbs: How Deep Should They Be Planted?
Pick a location where the soil won’t become soggy because alliums dislike having their feet wet because it can lead to the bulbs rotting. Plant the bulbs approximately 3 deep and 6–8 apart; for a more natural appearance, put them in groups of three or five.
Planting Allium Bulbs In Containers
Alliums’ regal forms look amazing when grown in pots and other containers. As long as there is sufficient drainage and the bulbs aren’t touching, you can plant them closer together than you would in a garden. Alliums are some of the spring bulbs that bloom the last, making them perfect for extending the period of interest. The best advice is to mix alliums with tulips and other spring-blooming plants like daisies or pansies in a pot.
Have you been seduced by alliums’ charms? From the colorful array of allium kinds we have available, pick your favorites.
How long are allium bulbs good for?
Post-bloom maintenance for alliums is quite simple. Simply continue to water the plants sparingly until they start to shrivel and turn yellow. At this point, you have the option of either dividing the plants or cutting them all the way to the ground.
Divide allium bulbs every three to four years. Simply use a shovel to dig around the plant and lift the bulbs out. You should see a group of bulbs that you may gently separate with your hands. Replant a few in the same location, and immediately transplant the others to different sites.
It’s considerably simpler to take care of allium bulbs that you don’t wish to divide. When the foliage starts to fade, simply trim it back, and in the fall, mulch the soil with 2 to 3 inches (5-7.5 cm) of material. In the spring, remove the mulch to allow room for fresh growth.
Do alliums proliferate?
Taller people can need assistance when exposed. After the flowers have faded, let the plant with them until they disintegrate because they make for wonderful winter interest. Some gardeners collect the seedheads and dry them so they can be used as home decor.
Allium bulbs can stay in the garden for multiple seasons. When planting new plants, try to keep in mind where you already put bulbs to prevent damaging those areas.
How to propagate alliums
In a few years, allium bulbs will grow in number. You may occasionally see the white bulbs being pushed out of the ground. Carefully pull the bulbs and gently peel out the offsets in late autumn or very early spring to replant them directly into the ground.
Allium can be grown from seed by leaving the flowerheads on the plant and harvesting the ripe seed to sow right away. Keep in mind that starting alliums from seed requires patience because it takes years to produce a flowering plant.
Growing alliums: pests and problem solving
A fungus called allium white rot prevents the growth of other alliums and onions. Clear and burn the infected plant material, and stay away from growing alliums in the same spot for at least five years, to prevent recurring infections.
Alliums have a tendency to outgrow their surroundings. Learn how to control the amount of alliums growing in a border in this Gardeners’ World video:
Which allium is best?
It seems sense that ornamental alliums are becoming more and more popular. The three most important criteria for gardeners across the nation are readily satisfied by these lovely plants: drought tolerance, deer resistance, and pollinator appeal.
The small list of plants that deer and insect pests tend to avoid includes alliums. The plants appear to be odorless, but when stepped on or chewed, their cell walls rupture, releasing volatile chemical compounds with a sulfur basis that have a strong sulfury stench and a bitter taste. Alliums are nearly indestructible as a result. While the blooms’ sweet nectar is very alluring to honeybees, bumblebees, and other pollinators, the leaves is repulsive.
Many garden alliums are indigenous to Central Asian mountainous areas, where the soil is thin and porous, the climate is hot in the summer and freezing in the winter. They can tolerate or even prefer dry growing circumstances as a result, which makes them great candidates for today’s water-conscious landscaping. They go well with ornamental grasses and other low-care perennials like salvia, sedum, rudbeckia, and echinacea.
ALLIUM BULBS PLANT IN THE FALL The majority of alliums grow from bulbs, much like their culinary relatives shallots and garlic. They bloom from late spring to early summer after being planted in the fall.
The best alliums are also the most impressive, including the large-headed varieties “Gladiator” and “Globemaster,” as well as the frequently planted A. aflatunense “Purple Sensation,” which blooms first. Its raspberry-purple, 3-inch-diameter flower heads, which are supported by 24- to 30-inch stalks and persist for up to two weeks, produce superb cut flowers.
Globemaster, His Excellency, and “Gladiator” bloom right after “Purple Sensation.” These alliums stand out with blooms that are five to ten inches across on three to four foot stems. Long after the color has faded, their big seed heads remain appealing.
Other alliums planted in the fall also need to be included. Pure white, five-inch blossoms on the elegant “Mount Everest” plant. It’s a need for any garden that is entirely white, together with the misleadingly termed black onion (A. nigrum). The tumbleweed onion (A. schubertii), which has flower heads that appear to have been captured mid-explosion, may be the most peculiar-looking allium. Maroon A. atropurpureum, star of Persia (A. christophii), and two-tone drumstick allium are three equally attractive species (A. sphaerocephalon).
ALLIUMS CLUMPING The most striking flowers are produced by ornamental alliums that grow from bulbs, but small-headed alliums still have a certain allure. These plants have thick clumps of roots that they emerge from, and their foliage is always lush and green. These non-bulb alliums begin to bloom in the early summer and, depending on the species, can continue all the way through October.
A hybrid of A. nutans, or Siberian chives, called “Millenium” is one of the best allliums that grows in clumps. On stiff, fifteen-inch stems that protrude above a neat clump of foliage, the purple, two-inch spherical flowers open in the middle of July. The long-lasting flowers are perfect for trimming. Other summer bloomers include the lavender-pink ‘Summer Beauty’ and the light pink ‘Sugar Melt’.
Look to A. tuberosum for a late summer star. This edible plant is often known as garlic chives in herb gardens, but its pure white blossoms on 20-inch stems make it an excellent choice for the flower border. The final allium of the year, Allium thunbergii ‘Ozawa, has orchid-pink blossoms that are a significant source of nectar for pollinators who are still out foraging in the late fall.
PLANTING ALLIUMS Most alliums may be grown in USDA Hardiness Zones 3 to 9, and they are robust, cold-tolerant plants. They generally don’t care much about the soil, though the ones with big bulbs need adequate drainage. They are also hardly ever bothered by rodents or deer, and they are virtually impervious to disease and bug concerns.
Alliums for decoration that come from bulbs should be planted in the fall. They look best planted in clusters, just like other flower bulbs planted in the fall. You should plant more bulbs in each group the smaller the bulb is. However, as their foliage will wither a few weeks after flowering, the bulbs can be planted practically anyplace. In order to assist cover the withering leaves, it is actually ideal to have adjacent plants.
Anytime during the growing season is suitable for planting the clump-forming alliums. They make wonderful pass-along plants because they are simple to divide and don’t hate being transferred. By removing the flower stalks after they have finished blooming, you can maintain these plants looking neat and reduce self-sowing.
At her Vermont home, Kathleen LaLibert writes and tends to her gardens. The National Garden Bureau is providing this material as a service. Image of the millennium courtesy of Walters Gardens.