How To Plant Giant Allium

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 can wait to be planted because it is remarkably 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.

Will huge allium grow further?

Under ideal conditions for growth, enormous allium bulbs will proliferate quickly, which can cause overcrowding and a loss of vigor. Fewer or smaller blooms may suggest that a bunch of established gigantic alliums needs to be divided sooner even though it usually takes several years for the bulbs to grow congested.

Alliums can be moved in the spring. The best time to lift and divide the bulbs is in late summer, when the ground has dried out and the foliage and flower stalks have completely withered away. When the smaller, newly formed bulbs are ready, remove them and plant them in nursery pots or in a different bed.

Which month is best for planting allium bulbs?

Alliums, often known as ornamental onions, are a popular summer plant in contemporary gardens because they are adaptable and simple to grow. These lovely blooms, which come in a variety of colors and sizes, are ideal for any garden, no matter how big or tiny. See our gardening guide below for information on when and how to plant allium bulbs.

Allium bulbs need to be planted in the yard in early autumn if you want to produce these striking blooms for the late spring/early summer season (September-October).

Choose a location

Alliums grow best in protected settings with direct sunlight. They dislike being completely exposed to the elements. Tall alliums look fantastic towards the back of a border, while small types work well in pots, depending on the size of the allium.

Type of soil

In a soil with good drainage, alliums will thrive. They detest flooded ground.

putting seeds in the ground

Plant the bulbs at a depth that is around three to four times their size. Larger bulbs should be placed roughly 15 cm apart, while smaller lights can be placed about 10 cm apart.

planting in containers or pots

The best containers for alliums are deep ones. Use a multipurpose compost in a container with good drainage, and water it thoroughly.


Drainage will be improved if the pot’s bottom is filled with broken pots or stones.

Before planting, should allium bulbs be soaked?

For example, Allium Giganteum (Giant Allium) frequently has a bulb that is 2-3 inches long “tall. Then, place this bulb between 6 and 9 “deep within the earth. “Pointy end” up when planting bulbs Once all the bulbs have been planted, thoroughly wet the area.


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.

After planting, should I water my allium bulbs?

Alliums are drought-tolerant, thus it’s typically not essential to water plants that are rooted in the ground. Summer irrigation is not preferred by plants since it could lead to bulb rot. Alliums planted in containers will require routine watering, but watch out for soggy compost.


Winter cold can be more damaging to plants in pots. to ensure their winter survival

  • Place containers in a protected area.
  • Place them in the lee of a wall, within a cold frame, or a greenhouse to provide them with some protection from the winter rain.

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 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 is a huge allium cared for?

To add height and beauty to your spring garden, plant some allium bulbs in your October bulb planting. For tall, scattered color throughout your beds next year, scatter them among the bulbs of lilies, crocus, and some of your other favorite spring blooming bulbs. Plant seeds of the candytuft flower and other short perennial flowers once the soil has warmed up to cover the developing alliums’ foliage as it withers away after the show is finished.

In a sunny area, plant the allium bulb three times its height deep in well-draining soil. Alliums can ward off aphids, which frequently enjoy sucking on the sensitive new growth of other spring blooms. Rodents, the peach borer, and even the destructive Japanese beetle are deterred by growing alliums in the garden.

If planted in the appropriate soil and sunlight, allium maintenance is easy. The allium plant simply requires infrequent weeding, fertilizing, and watering. Both rainfall and the use of organic mulch after planting could meet these requirements. Pre-emergence organic weed blocks or mulch may reduce the need for weeding.

Many of your other growing specimens will benefit if you learn how to plant allium bulbs. You will use this gardening tip for years to come: learning how to grow alliums.

How should I plant my allium bulbs?

Depending on the size of the bulb, plant them anywhere between 2 and 12 inches deep. Plant alliums with their pointed tops and flat bottoms facing up.

Are alliums self-propagating?

The cultural needs for ornamental alliums are quite minimal and they are hardy to zone 4. As long as the soil is well-drained, they can grow in almost any type of soil. Alliums love the sun and thrive when they have access to it throughout the day. They can be left unattended in the same place for years because the majority of them organically proliferate.

Drought-tolerant alliums actually prefer to be grown in dry conditions. They are not bothered by any dangerous illnesses or bug infestations. And since deer and rodents don’t appear to enjoy the taste of onions, whether they are ornamental or not, you won’t ever have to worry about them.

Just keep in mind that alliums can only be planted throughout the fall. Most garden centers have daffodils, tulips, and crocuses readily available, but alliums are less common. The best course of action is to order the bulbs via mail so that they are ready for planting when you need them. In this manner, you can be sure that they will arrive at your door at the appropriate planting time and that you won’t have to go another year without having these lovely, resilient, and bee-friendly flowers in your garden. Some ornamental alliums develop more along the lines of chives, and you plant clumps of roots as opposed to bulbs. This particular allium is typically marketed as a potted plant, and spring may be a better time to buy it than fall.