There are two types of allium, those used in the kitchen (such as garlic, onions, or chives) and those considered purely ornamental. They come in a wide range of heights, from tiny 8″ inches to nearly 5′ feet tall, making excellent companion plants for crop and ornamental gardens.
One great example is the drumstick allium, Allium sphaerocephalon (AL-ee-um sfay-roe-SEF-ah-lon). Here’s all you need to know about this wonderful plant and how to grow and propagate it.
What Are Drumstick Alliums?
Alternatively known as Allium sphaerocephalum by some enthusiasts (although not an official botanical name), this ornamental allium plant has many common names, including:
- Bald-Head onion
- Drumstick allium
- Ornamental onion (a shared common name for all non-culinary alliums)
- Round-headed garlic
- Round-headed leek
One of the key attractions to this particular allium is that it doesn’t bloom until June and will continue to impress through late summer and into fall.
Drumstick allium is also one of the taller alliums and can reach 36″ inches in height, although it’s still dwarfed by the 5′ foot tall giant onion (Allium giganteum).
The umbel flower heads are egg-shaped and tend to creep up on you.
In May, the buds are almost unnoticeable, blooming green in June before shifting to a beautiful burgundy-red that draws bees and butterflies.
In July, pollinated flowers may turn to seed, providing visual appeal while attracting birds.
As with many alliums, the heads can also dry if not pollinated to hold their color long after the flower has died, making them great for flower arrangements.
If growing from seed, this perennial won’t hit its first bloom time until it’s matured in the second growing season.
Drumstick allium is cold hardy and can be grown in gardens throughout USDA hardiness zones 4 to 8 and 9a.
They’re resistant (and repellent) to deer and rabbits while also chasing off a wide range of pests and being resistant to most diseases.
Their weaknesses include strong winds (they can be top-heavy and may need support), allium miners, onion flies, downy mildew, and white rot.
This moderate grower can spread like weeds if left untended and is toxic to cats, dogs, and horses.
It’s also debatably toxic to humans, as the high level of sulphates can cause indigestion, resulting in mild symptoms such as diarrhea, nausea, or vomiting.
Growing And Planting Drumstick Bulbs
Alliums are quite easy to grow in both gardens and containers, but half the fun is adding more to your collection.
Let’s first look at the basic growing needs, then how to germinate and raise these plants, then finally talk a little about their uses.
Alliums are very forgiving, but there are still a few guidelines to follow:
Drumsticks need at least 6 hours of full sun.
This is a simple matter in temperate climates, but they might need a bit of afternoon shade in harsher climes.
There are no specific temperature or humidity needs, and the plant can survive freezes once established (however, frequent freeze-thaw cycles can lead to rot if the bulb’s not properly insulated).
High temperatures can lead to a weaker stem, especially in the spring.
High humidity can lead to rot, but these plants are drought-tolerant and can handle arid weather.
Food And Water
Using the soak and dry method, water Drumstick allium when the soil feels dry 1″ to 2″ inches down.
They won’t need feeding but appreciate organic compost when planting or in early spring.
Any soil with a pH of 5.5 to 6.5 will do, but Drumstick allium needs to be well-draining, or you’ll risk rot.
This means clay soils must be amended with coarse sand or perlite and preferably a bit of organic matter such as peat moss.
However, the plant thrives in sandy soils with high organic content, so a great potting choice would be a 50/50 blend of coarse sand and African violet potting mix.
Division is the great go-to for all alliums (including cultivars), although you can also grow this plant from seeds.
Complete instructions for both are given below.
Note that drumstick alliums will self-seed and also expand underground if not maintained.
Here are the steps you need to follow for seed propagation:
- Deadhead the flowers in early to mid fall when they’ve gone to seed but before they’re able to shed their capsules.
- Rub the seeds in your hand to separate the chaff and store them for up to two years in a sealed container in a cool, dark spot.
- To plant, wait until the final frost has passed (you don’t have to wait this long if planting indoors in a seed tray) and turn the area, ensuring you have well-drained soil.
- Sprinkle the seeds liberally across the tray or planting area and add 1/4″ inch of soil on top.
- Gently saturate the soil and ensure it stays lightly moist while germinating.
- Once germinated, thin the seedlings out to 6″ inches apart.
- If growing in trays, give them pots or transplant the seedlings to your garden once the risk of frost has passed.
For Growing from bulbs (Divided or Store-Bought), do the following:
- Dividing is best done in the fall after the foliage has died back to ensure the bulbs have the maximum amount of stored energy.
- Gently excavate by digging a 6″ inch radius around the plant sand approximately 9″ inches down, then remove any remaining foliage from the uprooted plant.
- You’ll see multiple bulblets under the clump, and you’ll want to tease approximately half of these apart.
- Plant the bulbs approximately 4″ to 6″ inches apart at the same depth they were before uprooting.
These will come back the following spring as individual plants.
You can then plant the remaining bulbs in a new spot, give them as gifts, or pot them.
Note that you can also overwinter bulbs in a cool, dark spot and plant them in the spring.
Drumstick Allium Uses
These make excellent defenders for most garden plants.
When planting as a border, place them towards the back, and you can intersperse them in a bed as long as the other plants aren’t the same root depth.
The egg-shaped flower heads aren’t just great for the shape; the flower color attracts pollinators, and this allium is nectar-rich.
Because it flowers in summer, you can mix it with early bloomers at planting time to ensure your garden always has an interest.
Just remember, the slender stems are sensitive to high winds, so you may want to choose plant types that are a little shorter and can disrupt the wind.
More on Alliums
- Allium Companion Plants – What plants are excellent companions to Alliums