When And How To Plant Alliums

Avoid the error of poking the bulb into a hole you dug in arid, unforgiving soil and covering it with fertile, modified soil. When bulb roots swell, they require at least two inches of healthy soil.

The most crucial requirement for allium is a well-drained soil, as bulbs may rot in moist soil. In general, the soil in most garden beds is OK as long as it is kept moist but not soggy.

Space plants 8 to 12 feet apart for single intensive plantings, depending on the impact you want to achieve. Place accents up to 2′ apart if they have greater types. Many species do not spread at all, whilst some species spread rapidly through seeds or bulbils.

Planting: For a spring bloom, plant bulbs in the fall. In the fall, plant dormant allium bulbs in accordance with your growing zone. Place them in a well-drained sunny or partially shady spot at a depth of 2–3 times their diameter (4-6).

Allium may wait to be planted because it is incredibly hardy in a dormant state, but it must go into the ground a few weeks before the ground freezes in order to establish roots. Keep cold, dry, and hidden if storing for any period of time.

What month should alliums be planted?

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.

Do alliums reappear each year?

The foliage of the allium often appears at least a month before the flowers do. Some species’ foliage starts to turn yellow and die off before the flowers are fully open. Plant the bulbs with other plants that will obscure the wilting foliage to help mask it. Alliums do well with hosta, astilbe, and perennial geranium.

When your alliums are blooming, you may anticipate seeing a lot of pollinators. Any type of habitat garden will benefit greatly from the inclusion of these bulbs.

Like their relatives in the vegetable garden, alliums hardly ever have insect or disease problems. Rarely do bothersome rats and deer show any interest.

Most alliums are perennial plants. They will typically bloom again if the species you are planting is winter hardy and the bulbs are suitable to the growing environment in your yard.

Caring for Alliums After They Flower

Allium wasted flower heads can be removed or left in situ once flowering is over. The seed heads are viewed as an intriguing decorative element by many gardeners. Depending on your environment, they may persist far into the beginning of the fall.

Large-headed alliums like Schubertii and Globemaster hardly ever produce viable seeds. Purple Sensation and drumstick alliums will reseed if the conditions are favorable. Simply remove the seed heads after the flowers have faded and before the seeds develop to prevent a carpet of tiny volunteers.

There are herbaceous alliums as well as alliums that grow from bulbs, including varieties like Millennium and Summer Beauty. These plants have a big root system and come back every year to blossom.

Alliums that emerge from bulbs require their foliage in order to generate energy for the blossoms of the next year. Therefore, it’s crucial to let these plants die back organically. The leaves may typically be removed with a simple tug once it has turned yellow and dried. Trim off the wasted blooms from herbaceous alliums with hedge shears or scissors once they have stopped blooming. This will maintain the plants’ clean appearance and might promote a second flush of blossoms.

How late can allium bulbs be planted?

Yes! Alliums are annual plants that grow again year after year. Due of their extreme cold tolerance, they can endure most zones’ winters.

Alliums planted in the spring will still blossom, yes. Although the blossoms won’t be quite as big, they will return the next year in full force.

Allium may only grow as foliar growth, with no blooms, or not at all, if you plant it too deeply. To ensure the best growth and lessen the possibility of shallow bulbs being dug up by animals, try to put allium 4 inches beneath the soil surface.

The spring is not the time to transplant allium bulbs. Wait until the end of the summer when the foliage begins to turn yellow so that the plant will be in a dormant state and not be concentrating on new growth. It will be difficult to locate the bulbs if you wait until the stems totally wilt.


The allium family includes the chives in your herb garden, which are little, fluffy purple balls that bees and butterflies adore. Alliums used as ornaments, however, are anything but tiny. Big drama is what these enormous globes on tall stems are all about in your landscape. Alliums are a great choice if you are growing bulbs with kids since they enjoy the fact that when these blooms bloom, they frequently tower over them.

Garden & Container Planting

Alliums require a cold spell to establish their roots and get ready for spring, just like other flower bulbs do. So it’s time to start planting as soon as the first chill of fall appears in the air.

Although flower bulbs are hardy and simple to grow, they detest getting their feet wet since they can quickly decay if left to “bathe” in water. Therefore, avoid at all costs moist soil. this refers to locations where puddles are still visible 5–6 hours after a downpour. You can also improve possibly wet soil by incorporating organic material like peat, bark, or manure. The same motto applies when planting bulbs in containers: drainage, drainage, and more drainage. Purchase a container that has at least a few drainage holes at the bottom.

Because alliums require a lot of light to flourish, locations with less than full sun are not suitable.

Alliums must be buried deeply enough so that changes in the temperature above ground—either too warm or too cold—won’t influence them. Because containers can’t protect bulbs as well as mother earth can, it may be preferable to let your containers spend the winter indoors in a cool, dark, well-ventilated area where the temperature won’t rise above 60 degrees Fahrenheit, such as an unheated basement or garage, if you live in one of the hardiness zones 3 to 7.

The bulb is placed at the bottom of the hole with its sharp end facing up, and a hole three times as deep as the bulb’s height is dug to determine the optimal depth. When competing for nutrients with other bulbs, alliums perform worse, therefore it’s best to space them 6 to 8 inches apart.

After planting, it’s crucial to give the bulbs plenty of water to help them settle and develop roots rapidly, but after that, you won’t need to water them again. All that’s left to do is wait patiently for spring to come and surprise you with the fruits of your labor and for winter to work its magic underground.

Alliums don’t typically need watering during the flowering season, but you can water them if there hasn’t been any rain for three to five days.

Don’t trim the foliage of alliums right away after they have stopped flowering; through photosynthesis, the leaves will produce the nutrition the bulb needs for its subsequent growing season. The leaves will naturally turn yellow and die back after a few weeks, at which point you can remove it. The bulb will now enter dormancy and won’t require watering again until the following spring.

How to plant alliums in your garden:

  • Wait till the soil is 60°F or colder before planting. This will happen around September or October in the North and October or November in the South.
  • Choose a location in your garden that has soil that drains properly and receives full sun.
  • The allium bulbs should be planted with their pointed ends facing up, 4 to 8 inches deep, and 6 to 8 inches apart.
  • once, and then wait until spring.
  • Don’t remove the leaf from alliums after they bloom. Remove it once it has entirely withered and become yellow.

How to plant alliums in containers:

  • Wait until the soil temperature is at least 60 degrees Fahrenheit and the weather is chilly. This will happen around September or October in the North and October or November in the South.
  • Choose a location in your garden that receives direct sun.
  • Find a container with good drainage, fill it with loose soil, and make sure that water won’t collect and pool at the bottom.
  • The allium bulbs should be buried in the ground with their pointed ends facing up, 4 to 8 inches deep, and 6 to 8 inches apart. You can try putting the bulbs closer together since containers frequently have a small amount of room, but make sure they never touch.
  • If you reside in hardiness zones 3–7, you can water well once and wait until spring, or you can bring the containers inside and let them spend the winter in a cool place like an unheated garage or basement.

Special effects

You can choose the extremely regulated technique if you prefer order and cleanliness or if you want to maximize the wow-factor alliums can provide to your garden or container. Grow your alliums in straight rows with roughly 10 bulbs spaced closely apart (you might want to add some fertilizer to the soil to make sure they still get all the nutrients they need). Growing a row of 10 taller alliums, like Purple Sensation, behind a row of 10 slightly shorter ones, like Azureum, can produce an even more dramatic effect.

What depth should allium plants be buried?

Consider your garden space when choose which alliums to cultivate. Will you be bulk-planting in pots or growing in drifts through the border? as a component of a structured planting plan for prairies? Additionally, it’s crucial to consider the color of your alliums. Although most allium blossoms are purple, some are also blue, white, yellow, and pink in color. Also take into account the size of your allium—both the size of the flowers and the plant’s overall height. Allium flowers can range in size from a few centimeters to over 20 cm (8 in) in diameter, and their eights can also differ greatly.

Planting large, tall alliums singly or in drifts works nicely for varieties like “Purple Rain” and “Globemaster.” Allium christophii and other shorter variants grow well in containers. In prairie planting designs, drumstick alliums like Allium sphaerocephalon look fantastic.

Alliums thrive in a sunny location with excellent soil drainage. They don’t care what kind of soil it is. Plant higher-growing cultivars in the back of a border and lower-growing varieties up front. Although alliums do well in containers, their strappy foliage can become ugly after flowering.

The leaves of alliums develop before the flowers do. As a result, they are frequently better suited to the center of a border where the faded foliage would be hidden and the flowers will put on a display. Plant alliums among attractive grasses and perennials to hide the fading foliage.

Grow alliums in broad drifts through the border or let them naturally grow in your lawn for a striking show.

How to plant alliums

Plant allium bulbs in the fall, at least four times their size deep (at least 15cm deep). It is preferable to plant them deeply rather than superficially.

There is no need to water them in if the soil is damp. Poor soils should be fertilized with a balanced fertilizer in the spring as growth begins to show.