What Month To Plant Allium Bulbs

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.

What season should you plant allium bulbs?

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.

Can you plant allium in the spring?

QUESTION: When is the best time to plant alliums? I didn’t plant my onions and garlic in the ground as usual in the fall. Norma G.

Don’t worry, you can plant all of your alliums in the spring just like you can in the fall. Your alliums’ potential size won’t be the same if you plant them in the spring. Instead, employing the spring planting method will result in excellent, slender-necked bulbs topped with vibrant greens. Here are the directions for springtime planting of chives, green onions, onions, and garlic.

Planting Onions in the Spring

Onions can be planted in the spring either as sets or by sowing the seeds indoors in advance. While the weather is still cool, prepare to plant onions in the outside garden. Until the weather warms up in the spring, the onions will rest in a dormant state. Their signal to begin growing seriously is that.

Plant your seeds in the garden as soon as the earth is warm enough to work in areas where the winters are exceptionally chilly. This typically occurs in March or April, near the start of spring. Look up the weather prediction in advance. When planting your onions, you should choose a day when the temperature will remain above 28 degrees Fahrenheit.

You must plant the seeds six weeks prior to transferring the sets of onions to your garden if you choose to grow your onions from seeds rather than sets. From the date you choose in the preceding sentence, count backward. The seeds should be stored indoors, in a dry, secure area, at room temperature. In order for onion seeds to sprout, the environment in which they are sown must consistently be warmer than 50 degrees Fahrenheit.


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.

When do I plant UK-grown allium bulbs?

Allium bulbs can still be planted for a fantastic spring show. The photographs demonstrate how Alliums, when planted properly, are low maintenance, return dependably each year, and are unquestionably one of the most fashionable plants for a border.

Alliums prefer a sunny location with well-drained soil, therefore they do not do well in wet, marshy soil, especially during the winter when the bulbs may rot. Alliums can be grown in containers for a patio display or placed in the borders if you don’t have the best growth conditions.

A. Moly, a bright yellow variety, and Chives, which the bees love (see second image), both of which grow to about 30 cm, are relatively little and perfect for the front of the border. The bees and we both enjoy eating chives, which make a great edging plant.

The outstanding Allium Cristophii (shown third image), one of the tallest kinds above 1m, and A. Globemaster are two of the taller types.

It is recommended to plant alliums in the first two weeks of October because they require to be planted in the early autumn. Bulbs may be purchased and planted for a lot less money than plants can this spring. As with all bulbs, it is ideal to plant them in pots that are four times as deep as the bulbs themselves.

Unusual variants include Nectaroscordum siculum, which is technically not an Allium but is sometimes sold as one (6th image).

Although most of us don’t have so much space, alliums look fantastic when planted in large groups, as in photographs 4 and 5, which are from an RHS garden. Alliums can be utilized well as a theme in smaller gardens when planted in groups and recurring perhaps 3/4 times. This will give a border true style.

Staking may be necessary for taller varieties, particularly in exposed places. Allium are simple to grow and put on a fantastic display. They offer good value for money because they come back and bloom year after year with little care.

Allium’s leaves are not appealing, especially after flowering, hence historically, companion plants like Achillea Mollis or Euphorbia have been planted with Allium to hide the leaves.