There are several hundred species of Allium plants. Perennial Ornamental Alliums are members of the onion family. Among the best known Alliums are chives, onions, garlic, and shallots. For the flower gardener, there are many varieties of Flowering Allium, also called “Flowering Onion”. Growing alliums is a cinch. They are often found in natural settings growing without assistance. They spread readily and pretty much take care of themselves.
This hardy, easy-to-grow flowering bulb comes in a wide variety of colors, heights, and blooming times. Big, multi-floret, round blooms are produced atop of a tall, sturdy spike. In general, they bloom from late spring to early summer. Once established in your flower garden, they will likely grow for many, many years with little attention.
As an ornamental, the largest, giant varieties are the most sought after. They are also known as Allium Giganteum.
Flowers Bloom: Early Spring. Also, there are fall-blooming varieties.
Flower Colors: Green, pink, purple, yellow, and white.
Plant height: 1 to 4 feet tall.
Hardiness Zones: 4 – 10
Ornamental Onions, or perennial Alliums, are grown from bulbs. The flower head also produces seeds, but most gardeners plant easy-to-handle bulbs.
Plant Allium bulbs in the soil in the spring, as soon as the ground can be worked. Plant them to a depth of twice the diameter of the bulb.
If planting Allium seeds, sow them directly into the garden, planting just 1/8″ deep.
Days to Germination: 10 – 14 days.
Growing Ornamental Alliums is very easy to grow. They like full sun to partial shade.
The plants tolerate poor soils but prefer the soil to be well-drained. Adding a general-purpose fertilizer once in early spring will give them a boost on the season.
Once your Ornamental Allium plants are established, they should grow well with few problems. Keep the soil moist to slightly dry. Water them during dry periods, once or twice per week.
Keep the plants well weeded. And, apply a 2-3 inch layer of mulch around the plants, for a tidy appearance.
Allium plants should come back yearly for many years.
Allium plants become overcrowded after several years. Dig up the bulbs and separate them. Then, re-plant the bulbs. And, give some to gardening friends!
Did You Know? Alliums are as cut flowers. But, they will give off a slight onion scent… no surprise there!
Ideal Soil pH: 5.5 – 6.5.
Plant Problems – Identify the causes and find the cures.
Allium plants have few insect or disease problems.