🌲 Front Range Plant FinderPlant finder

Geyer’s onion

Allium geyeri

Compiled by · Reviewed against the 2024 Front Range Tree Recommendation List, CSU Extension & Plant Select® · Updated 2026-07-04

Geyer’s onion (Allium geyeri) 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

Photos

Plan your garden

Not sure what to plant? The finder matches Front Range trees, shrubs, perennials, and groundcover to your soil, water, sun, and zone.

Ready to plant this?

At a glance

Botanical name
Allium geyeri
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
Bloom time
early summer
Pollinator value
high
Site uses
Slopes & erosion control

Things to know before you plant

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 Geyer’s onion good for the Colorado Front Range?
Yes, Geyer’s onion is a well-suited perennial for Colorado's Front Range.
What should I know before planting Geyer’s onion?
The main things to know: Considered toxic to dogs, so keep pets away from it and check with your vet.
How big does Geyer’s onion get?
It matures to about 12 in tall and 6–12 in wide.
How far apart do I plant Geyer’s onion?
Space Geyer’s onion about 8 in apart for a faster, fuller bed, or up to 12 in apart for a looser planting.
Is Geyer’s onion hardy on the Front Range?
Geyer’s 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 Geyer’s onion need?
It needs low to medium water once established.
Is Geyer’s onion safe for dogs?
No. Geyer’s onion is considered toxic to dogs. Keep pets away and check with your vet.
Is Geyer’s onion deer-resistant?
Geyer’s onion is generally considered deer-resistant, though no plant is deer-proof when browse pressure is high.
Is Geyer’s onion a good firewise plant near the house?
Geyer’s 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 Geyer’s onion bloom?
Geyer’s 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.

Find Geyer’s onion near you

See also

Related perennials