nodding onion
Allium cernuum
nodding onion (Allium cernuum) is a Colorado-native perennial suited to the Colorado Front Range. It matures to about 12 in tall and 6–12 in wide, needs low to medium water, and prefers full sun to partial shade. Fire-wise zone 1-2 perennial; ignitability rating 10.0/10.
Colorado nativeOn the CSFS firewise listlow to medium water12 in tall and 6–12 in wideXeric / water-wiseDeer-resistantToxic to dogs
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At a glance
- Botanical name
- Allium cernuum
- Type
- Perennial
- Mature size
- 12 in tall and 6–12 in wide
- Planting spacing
- ~8–12 in apart
- Bloom length
- Long (several weeks)
- Hardiness zones
- USDA 3–9
- Water needs
- low to medium water
- Sun
- Best in full sun; tolerates partial shade.
- Colorado native
- Yes
- Foliage
- Deciduous
- Soil
- clay, loam, sandy
- Soil pH
- 6.5–8.0
- Hail tolerance
- high
- Wind tolerance
- high
- Salt tolerance
- moderate
- Firewise (defensible space)
- Zones 1–3 (can be planted near the house)
- Bloom color
- pink, purple
- Bloom time
- early summer
- Pollinator value
- high
- Site uses
- Slopes & erosion control
Things to know before you plant
- Toxic to dogsConsidered toxic to dogs, so keep pets away from it and check with your vet.
Wildlife & ecology
- Pollinator value
- high
- Deer
- Generally deer-resistant
- Native ecoregion
- shortgrass prairie, foothills
Planting & establishment
Deep-water first season to establish, then minimal water needed.
Frequently asked questions
- Is nodding onion good for the Colorado Front Range?
- Yes, nodding onion is a well-suited perennial for Colorado's Front Range.
- What should I know before planting nodding onion?
- The main things to know: Considered toxic to dogs, so keep pets away from it and check with your vet.
- How big does nodding onion get?
- It matures to about 12 in tall and 6–12 in wide.
- How far apart do I plant nodding onion?
- Space nodding onion about 8 in apart for a faster, fuller bed, or up to 12 in apart for a looser planting.
- Is nodding onion hardy on the Front Range?
- nodding onion is hardy in USDA 3–9. The Colorado Front Range spans roughly USDA 4b–6a, so it is well within range.
- How much water does nodding onion need?
- It needs low to medium water once established.
- Is nodding onion safe for dogs?
- No. nodding onion is considered toxic to dogs. Keep pets away and check with your vet.
- Is nodding onion deer-resistant?
- nodding onion is generally considered deer-resistant, though no plant is deer-proof when browse pressure is high.
- Is nodding onion a good firewise plant near the house?
- nodding onion is a lower-fuel choice suitable in defensible-space zones 1–3, it can be planted near the house when kept well irrigated and maintained. This is general suitability guidance based on CSU Extension firewise plant lists, not a guarantee that any plant won't burn, a well-irrigated, well-maintained plant is the goal. Follow CSU Extension defensible-space guidance and check with your local fire district before planting in the wildland-urban interface.
- How long does nodding onion bloom?
- nodding onion blooms for several weeks, a long-season performer on the Front Range. Bloom timing shifts a week or two with elevation and spring weather.
