Alliums can thrive in either full or partial shade, however full sun is preferred.
The bulbs are typically winter-hardy in hardiness zones 3–8. See this USDA Hardiness Zone Map to determine your growing zone.
Alliums require well-drained soil that does not become wet in order to be cultivated, just like the majority of other bulbs.
Where to Plant Alliums
Most alliums bloom in late spring, right after the last tulips and before irises and peonies, in perennial gardens. The flowers last for weeks and give the garden a balloon-like appearance as they float above it. After flowering, the foliage and flowers disappear, making space for summer perennials to take the lead. Allium christophii, Gladiator, Globemaster, Purple Sensation, and more excellent alliums for perennial gardens include these.
Alliums do well in rock gardens, where they flourish in the well-drained crevices between the boulders. Select species with smaller leaves, such as Allium sikkimense, Allium flavum, and Allium karataviense.
Alliums make great cut flowers, according to cutting gardens. The flowers remain a very long time and are easy to arrange thanks to their rigid stalks. You may guarantee that you’ll always have an abundant supply of flowers for bouquets by planting alliums in a cutting garden. You’ll receive flowers all season long if you select a variety. Purple Sensation, Allium atropurpureum, Mount Everest, Allium sphaerocephalon, and Allium tuberosum are all good choices.
Containers: Whether grown alone or in combination with other plants, many alliums thrive in containers. When the flowers blossom, you can relocate the planter to a visible location so that you can enjoy the flowers.
How to Plant Alliums
When to Plant: Bulbs-based alliums are planted in the fall, just after the first frost and before the ground freezes. Like other perennials, herbaceous alliums (such as Allium tuberosum and Allium millenium) have fibrous roots. You can plant these at any point of the growing season.
Planting Depth and Spacing: Planting depth is based on bulb size. Smaller bulbs, such drumstick alliums, should only be planted 3 deep in comparison to larger bulbs like Globemaster, which should be planted 5 to 6 deep. Follow the plant-specific directions on the packaging or on our website for the best results.
Planting advice: You don’t have to be concerned about deer, squirrels, or voles when growing alliums. Allium bulbs have an onion-like flavor that repulses them, and they almost invariably leave them alone.
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 soil 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?
Plant the bulbs approximately 3 deep and 6–8 apart; group them in groups of three or five, or scatter them in drifts for a natural effect. Alliums don’t enjoy “having their feet wet since this may cause the bulbs to rot.
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.
Allium bulbs can be planted in the spring.
If Spring is still in bloom where you live, it’s probably not too late to plant your allium bulbs!
Allium bulbs can be planted in the spring, but fall-planted bulbs will put on a spectacular display the following year.
Allium bulbs can be added to your garden whenever the soil is suitable for planting and you can dig a hole deep enough.
Having said that, blooms planted in the fall will perform best in their first year. First-year flowers from spring-planted bulbs may be sparse, unlikely to blossom, and less vigorous than those from fall-planted bulbs. Or, plants might not blossom until the end of summer or the beginning of fall.
It’s not too late if you didn’t have time to plant those bulbs in the autumn.
Allium bulbs can be planted in the fall and spring, but you should avoid doing so in the early winter. Bulbs planted in the early winter won’t have enough time to take root properly and could perish when the ground freezes.
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.
Are allium bulbs contagious?
Spread alliums? Yes, the plant’s bulbs and seeds will grow and spread without much help from you. Typically, they will disperse at their own rate and stay put until they are moved or split.
What happens if alliums are planted too late?
Q I’ve discovered several forgotten spring-flowering bulbs. Does it still make sense to plant them?
A Which? Gardening magazine investigated this question by planting six popular spring bulb varieties at various periods between mid-September and early January.
A The plants that produced the best results for the early flowering Narcissus ‘Tte—tte’ were those that were planted in early October and spent four weeks in full bloom in March. Despite the fact that the time spent in full bloom was cut in half, we nevertheless achieved good results with bulbs planted as late as December. Plants that were planted in January grew shorter, later, and finished flowering two weeks sooner. With the later-flowering Narcissus ‘Passionale,’ there was even less variation; they all flowered well and for about the same amount of time in mid-April. WHICH? VERDICT OF GARDENING MAGAZINE Early autumn is ideal, although plantings in December can still produce respectable results.
A traditional recommendation is to plant tulips in mid- to late-autumn, later than other bulbs, to lower the chance of tulip fire. We found that plantings in late October and November had the optimum emergence, flowering time, and flower quality. With tulips planted in September and the first few days of October, we had losses of up to 25%. The bulbs held their shape well and did not sprout. Early “Red Riding Hood” tulips, on the other hand, blossomed later, were shorter, and spent less time in full bloom after being planted in December and January. Although they flowered for a shorter period of time, May-flowering ‘Queen of Night’ was least influenced by delayed planting. WHICH? VERDICT OF GARDENING MAGAZINE Planting late-flowering types can be put off until late October or early November.
A Crocuses planted in early October compared favorably to those planted in September. The majority of the corms spent a month in full bloom starting in mid-February, and almost all of the bulbs sprouted. The whole flowering period lasted 63 days. Bulbs that were planted later began to bloom later, reaching their peak in late February or early March, and only lasted a fortnight in full bloom. The crocus corms began to sprout in early October, even though they stayed solid until January. Only 60% of the crocus that were planted in January survived, and their blossoms also weren’t as impressive. WHICH? VERDICT OF GARDENING MAGAZINE For a robust and early display, plant in September or early October.
A Muscari bulbs planted in September and early October maintained leaves throughout the winter and produced the best flower display toward the end of March, lasting five weeks at full bloom. If stored for a longer period of time, the bulbs produced some roots and shoots, but bulbs put later survived just as well as those planted earlier. They put on a fantastic display that lasted for four weeks until the beginning of April, growing to roughly the same height and flowering nearly as well as previous ones. WHICH? VERDICT OF GARDENING MAGAZINE As there is no impact on flowering time or flower quality, you can plant whenever you like.
A The longest total flowering time of five weeks was achieved by alliums sown in September, which blossomed in March and spent two weeks in full bloom in May. Bulbs planted after that lasted a week less in bloom, but the displays were still impressive and the blossoming time was only postponed by one or two weeks. The bulbs started to show signs of mold in October, and by January, they had grown tiny shoots. Though later planting didn’t appear to have a negative impact on the quality of the blooms, emergence was good. WHICH? VERDICT OF GARDENING MAGAZINE Although September is ideal, alliums from later plantings continue to bloom well.
A Irises planted in September and early October provided us the longest total flowering durations of eight and seven weeks, as well as the greatest quality flowers. All of the irises we planted were in full bloom for two weeks. Bulbs held their shape but started to sprout in November, making them a little more difficult to plant by January. From November plantings on, fewer bulbs emerged, and they flowered later. Irises planted in December and January were up to 25% shorter than those planted earlier, and the flower spikes bowed rather than rising straight. WHICH? VERDICT OF GARDENING MAGAZINE For strong displays of early color, plant in September or early October.