Firecracker Penstemon
Penstemon eatonii
Firecracker Penstemon (Penstemon eatonii) is a Colorado-native perennial suited to the Colorado Front Range. It matures to about 18 to 36 in tall and 12 to 18 in wide, needs low water, and prefers full sun. Fiery scarlet tubular flowers; hummingbird magnet; very drought tolerant evergreen rosette.
Colorado nativeOn the CSU listlow water18 to 36 in tall and 12 to 18 in wideXeric / water-wiseLow ignitability: OK 0-30 ft from the house, CSU score 8/10Deer-resistant
Photos
- Photo 1: gailhampshire from Cradley, Malvern, U.K, Wikimedia Commons (CC-BY)
- Photo 2: Stan Shebs, Wikimedia Commons (CC-BY-SA)
At a glance
Will it survive here?
- Hardiness zones
- USDA 3 to 8
- Water needs
- low water
- Sun
- Best in full sun.
- Soil
- clay, loam, sandy
- Soil pH
- 6.5 to 8.0
- Hail tolerance
- high
- Wind tolerance
- high
- Salt tolerance
- moderate
- Site uses
- Slopes & erosion control, Hot south- or west-facing walls
How big, what shape?
- Mature size
- 18 to 36 in tall and 12 to 18 in wide
- Planting spacing
- ~13 to 18 in apart
What it looks like, and when
- Bloom time
- mid spring, late spring
- Bloom color
- red
- Bloom length
- Long (several weeks)
- Foliage
- Evergreen
Who else benefits
- Pollinator value
- high
- Deer
- Generally deer-resistant
- Colorado native
- Yes
- Native ecoregion
- foothills
Also worth knowing
- Fire rating
- Low ignitability: OK 0-30 ft from the house, CSU score 8/10
Planting & establishment
Deep-water first season to establish, then minimal water needed.
Frequently asked questions
- Is Firecracker Penstemon good for the Colorado Front Range?
- Yes, Firecracker Penstemon is a well-suited perennial for Colorado's Front Range.
- How big does Firecracker Penstemon get?
- It matures to about 18 to 36 in tall and 12 to 18 in wide.
- How far apart do I plant Firecracker Penstemon?
- Space Firecracker Penstemon about 13 in apart for a faster, fuller bed, or up to 18 in apart for a looser planting.
- Is Firecracker Penstemon hardy on the Front Range?
- Firecracker Penstemon is hardy in USDA 3 to 8. The Colorado Front Range spans roughly USDA 4b to 6a, so it is well within range.
- How much water does Firecracker Penstemon need?
- It needs low water once established.
- Is Firecracker Penstemon native to Colorado?
- Yes. It is a Colorado native.
- Is Firecracker Penstemon deer-resistant?
- Firecracker Penstemon is generally considered deer-resistant, though no plant is deer-proof when browse pressure is high.
- Is Firecracker Penstemon a good firewise plant near the house?
- Firecracker Penstemon is rated 8 of 10 in CSU Extension Fact Sheet 6.305 (2025), where higher means less ignitable, so it can go within 0 to 5 feet of the house as well as out to 30 feet when kept watered and tidy. This is general guidance based on CSU Extension Fact Sheet 6.305 (2025), 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 Firecracker Penstemon bloom?
- Firecracker Penstemon blooms for several weeks, a long-season performer on the Front Range. Bloom timing shifts a week or two with elevation and spring weather.
