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.
What location is ideal for planting alliums?
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.
Where to plant alliums
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.
When do alliums flower?
There are numerous cultivable variants; the following are some of the best:
The 2 to 4 inch diameter purple globes known as “Purple Sensation” bloom in early June, just following the late tulips. Purple Sensation has robust stems that reach 24 to 30 inches in height, giving the flowers an airy appearance above the foliage of perennials that have just begun to emerge.
The tallest and most edifice-like alliums, Globemaster and Gladiator, feature enormous, globe-shaped flowerheads on 3- to 4-foot stalks. Early to mid-June is when plants bloom. Particularly when combined with white or pink peonies, delphiniums, or tall bearded iris, a group of deep-purple Globemaster or Gladiator alliums is a true eye-catcher. Shorter and more angular Mount Everest with white flowers stands out sharply in front of shrubs with deep green or burgundy foliage or when emerging from periwinkle groundcover (Vinca minor).
Allium thunbergii ‘Ozawa’ (Ozawa allium): a neat, clump-forming plant that reaches heights of 18 to 20 inches. Its flowers frequently don’t emerge until late September or October, making it one among the last perennials to bloom. It attracts bees. Another autumn-flowering late-bloomer. Its pink flowers go well with fall blooms like coreopsis, gaillardia, solidago, and others.
Corkscrew allium: In the dry soil at the top of my stone retaining wall, drought-tolerant corkscrew allium (Allium senescens ssp. montanum var. glaucum) makes a good edging plant. Its loose, blue-green leaves resemble corkscrews. Late July is bloom time.
Even though it is only 8? tall, the Schubert allium (Allium schubertii) is quite spectacular. Its foot-wide umbels resemble a pink fireworks display that is bursting. Visitors to the garden will undoubtedly comment on this. After the blooms have faded for a month or more, the seed heads offer interest.
Allium sphaerocephalon, also known as the drumstick allium, blooms in early July, a few weeks after Purple Sensation. The two-toned, burgundy-green heads are great in the correct setting (where casual is acceptable); but, they are not as upright and ordered as Purple Sensation. fantastic with decorative grasses.
Yellow allium (Allium flavum): A favorite with midsummer blooms that works nicely in rock gardens. The floret cluster steadily emerges over the course of ten days to become a riot of color. Similar species, 12 to 24 inches tall, are available in yellow, pink, and white.
When should I sow the allium bulbs I have?
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.
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.
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.