Glaucous Onion Firmament Allium
Allium glaucum 'Firmament'
Essentials
At a Glance
Plant Type
Bulb Corm Tuber
Height
12 inches
Width
10 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8
Water
Moderate
Humidity
Average
Lifespan
Perennial
Native To
Europe, Northern Asia
Toxicity
Toxic to dogs and cats
The Story
Plant Bio
Allium glaucum 'Firmament' is a compact flowering bulb known for its striking blue flowers and attractive foliage. This cultivar is particularly noted for its vibrant blue color and smaller stature compared to other Alliums.
Bloom Period:
Uses & Benefits:
Marketplace
Where to Buy
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Planting
How to Grow
- Tuck bulbs 4-6 inches deep in well-drained soil.
- Water thoroughly after planting to settle soil.
- Mist foliage during dry spells for best growth.
- Thin out crowded plants after foliage dies back.
- Divide clumps every 3-4 years in early fall.
- Mulch lightly to conserve moisture and suppress weeds.
Pro Tip
Plant in full sun with sandy or loamy soil for best flowering results.
Keep It Thriving
Care Guide
Do
- Water regularly during active growth 🌱
- Apply balanced fertilizer in early spring
- Ensure good drainage to prevent bulb rot
Don't
- Avoid overwatering in winter ❌
- Don’t plant too deep or too shallow
- Refrain from using heavy clay soil without amendment
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Divide | ||||||||||||
| Fertilize | ||||||||||||
| Plant |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Glaucous Onion Firmament Allium questions
What zones can Glaucous Onion Firmament Allium grow in?
Glaucous Onion Firmament Allium is hardy in USDA Zones 4–8. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Glaucous Onion Firmament Allium deer resistant?
Yes — Glaucous Onion Firmament Allium is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Glaucous Onion Firmament Allium bloom?
Glaucous Onion Firmament Allium typically blooms in late summer through early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Glaucous Onion Firmament Allium need full sun?
Glaucous Onion Firmament Allium does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Glaucous Onion Firmament Allium drought tolerant?
Yes — once established (usually after the first full season), Glaucous Onion Firmament Allium handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Allium to compare
Millennium Gold Onion Moly Onion
Allium x moly 'Millenium'
Drumstick Allium, Round-headed Leek
Allium sphaerocephalon
Purple Sensation Allium
Allium hollandicum 'Purple Sensation'
Ornamental Onion 'Ambassador'
Allium cybum 'Ambassador'
Globemaster Allium
Allium giganteum 'Globemaster'
Blue Eddy Allium
Allium senescens 'Blue Eddy'
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