Rosenbachianum Allium (Ornamental Onion)

Allium rosenbachianum are early bloomers in the late-spring parade of globe Allium. Unique and effortlessly elegant, they stand tall at 32-38" with 4" diameter dark-violet globes. Each globe has over 50 starry florets with darker mid-veins and white stamens. They can extend your season of enjoyment by blooming about 2 weeks ahead of the other globe Alliums (Ornamental Onions). Plant with white Mount Everest Alliums for lovely contrasting blooms.
Zones4 - 10
Advantages
Attract Butterflies
Bee Friendly
Deer Resistant
Rabbit Resistant
Good For Dried Flowers
Good For Containers
Light Requirements
Full Sun
Morning Sun & Afternoon Shade
Annual Rainfall
10 to 20"
Mature Plant Size20-24" tall
Bulb Spacing3 bulbs per sq. ft.
Bloom TimeLate spring
ShippingShipping begins the week of September 9th, 2019 Learn More…
SizeBag of 3
SKUHC008526

USDA Hardiness Planting Zones

To determine if a plant is sufficiently cold hardy, the USDA created numbered zones indicating winter low temperatures; the lower the zone number the colder the winter.

  • If the coldest winter temperature expected in your area is -15°F (zone 5) then any plants rated zones 3-5 will survive the winter temperatures in your area.
  • If you live in very warm winter areas (zones 9-11) plants with zones 3-4 ratings are not recommended. The lack of freezing winter temperatures do not provide a time for winter dormancy (rest).

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Regular Price $11.99 Sale $8.99
Per Bag of 3
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In stock
SKU
HC008526

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Details
Allium rosenbachianum (Showy Persian Onion) are essential flowers for all Allium-loving gardeners. The purple globes, like Spanish exclamation points, draw the eye and bring a smile. Allium rosenbachianum is a hard-to-find heritage variety in cultivation since around 1894. Blooming two weeks ahead of the other large Allium, they’ll extend your enjoyment of one of our most unique garden flowers. Plant these Allium in groups of three or so in a sun to part-shade location in enriched, well-drained soil. They work well planted in a perennial bed where the perennials will grow in and cover the allium’s aging foliage. Great cut flowers too, they are favorites of bees, butterflies and other pollinators. Easy-to grow, they are drought tolerant, deer and rabbit resistant and are nearly pest and disease free. There is something spectacular about Allium’s architectural and colorful presence in the flower garden.
More Information
SKUHC008526
Common Name
Rosenbachianum Allium (Ornamental Onion)
Botanical Name
Allium rosenbachianum
Zones
4, 5, 6, 7, 8, 9, 10
Light Requirements
Full Sun, Morning Sun & Afternoon Shade
Flower Color
Purple
Mature Height
20-24" tall
Bulb Spacing
3 bulbs per sq. ft.
Flower Bulb Size
14 cm
Planting Depth
Plant 6-8" deep
Bloom Time
Late spring
Advantages
Attract Butterflies, Bee Friendly, Deer Resistant, Rabbit Resistant, Good For Dried Flowers, Good For Containers
Amount Of Rain
10 to 20"
Soil Type
Sandy Soil, Average Soil, Drought / Dry Soil, Well-Drained Soil
Soil Moisture
Average, Well Draining
Item Package Size
Bag of 3
Ships As
Bulb, Rhizome, Tuber
Planting Time
Fall
Ideal Region
Northeast, Southeast, Midwest, West, Southwest, Hot Desert, Pacific Northwest, Coastal California, Suitable Above 7000 ft
Prohibited
Idaho, Oregon, Washington
Item Unit Of Measure
Bulb
Ships To Canada
No
Planting Guides

Tips on Growing Fall Planted Flower Bulbs

When you receive your spring bulbs (tulips, daffodils, etc.) keep them in a dry, dark, cool place until ready to plant. They need air circulation so they will not collect moisture and rot. Planting times can vary from early October in the North to mid-to-late November in the southern regions. A good rule of thumb is to plant them about 6 weeks before the ground is frozen or after the first hard freeze. For more information and a planting depth illustration, see pages 14-16 of our Planting Guide.

Soil Preparation for Bulbs

A compost-enriched, well-drained soil is best. Incorporate a good quality organic compost as needed. Yum Yum Mix® is recommended as an excellent source of nitrogen, phosphorus, and potassium needed for strong plants and healthy roots. Mix a small amount into the bottom of the hole before planting your bulbs.

Many bulbs prefer full sun exposure. However, Muscaria, Allium, Galanthus, Hyacinthoides, Scilla and many Daffodils will tolerate partial shade and bloom well. Pink daffodils will hold their color longer if planted in dappled shade or morning sun/afternoon shade.

After planting, add a top dressing of compost or other organic material and water in thoroughly. If your winter is dry, water every three to four weeks throughout the winter and add more mulch if necessary.

Protect your Bulbs

Apply a mole or gopher repellent to the surface of the ground to protect bulbs from these burrowing mammals. As bulbs sprout, use our Deer Off Repellent to prevent deer and rabbits from browsing your spring blooms.

After your Bulbs have Bloomed

Once your bulbs have bloomed, allow the bulb foliage to brown and fade naturally since the leaves are feeding the bulb in the ground. Removal of foliage weakens the bulb and leads to fewer blooms the following year. Planting your bulbs amongst your perennials is one way to conceal the dying bulb foliage. The perennials begin to grow and fill out as the bulb foliage dies back. The perennials will then provide foliage and color in the garden from late spring through the summer and into fall. Regular fertilization with balanced organic or natural fertilizer and a re-application of mulch each fall will ensure more and more beautiful spring bulb blooms for many years!


View more Planting Guides, or download our complete Planting Guide for tips on caring for your plants when you receive your order, as well as planting instructions for Perennials, Spring-Planted Bulbs, Fall-Planted Bulbs, Cacti & Succulents, Xeric Plants and more.
Shipping
ZoneShipping Status
Zone 2Shipping begins the week of September 9th, 2019
Zone 3Shipping begins the week of September 9th, 2019
Zone 4Shipping begins the week of September 9th, 2019
Zone 5Shipping begins the week of September 9th, 2019
Zone 6Shipping begins the week of September 16th, 2019
Zone 7Shipping begins the week of September 23rd, 2019
Zone 8Shipping begins the week of September 30th, 2019
Zone 9Shipping begins the week of October 7th, 2019
Zone 10Shipping begins the week of October 14th, 2019
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