Full sun / Part sun / Part shade

Low water

10-40" tall · 18" apart

3a-7b

brutally cold to cold winters

Warm-Extreme

warm to extreme summers Interim Plotwright tier until the plant AHS range is authored.

No

In plain terms: cold winters — coldest nights typically around -3°F.

Well-suited today, but likely marginal by 2050.

Common buckeye (Junonia coenia)

Penstemon is a documented common-buckeye host genus (Plantaginaceae); P. eatonii not individually cited, so genus-level inference.

Baltimore oriole (Icterus galbula)

Ruby-throated hummingbird (Archilochus colubris)

The Lady Bird Johnson Wildflower Center documents that firecracker penstemon attracts hummingbirds; its narrow scarlet tubular flowers are a textbook hummingbird-pollination syndrome. (The ruby-throated hummingbird stands in here for the western hummingbirds — e.g. broad-tailed, black-chinned — that overlap this species' Intermountain West range; Plotwright's wildlife catalog does not yet carry those western species.)

Stem-nesting native bees (multiple genera (Ceratina, Hylaeus, Osmia, etc.))

The Lady Bird Johnson Wildflower Center flags Penstemon eatonii as of "Special Value to Native Bees" (a Xerces Society pollinator-value flag).

Native across 6 US states.

Naturally belongs in 12 ecoregions — its native range crosses a state or province each one spans (not necessarily this exact habitat).

The Lady Bird Johnson Wildflower Center documents Penstemon eatonii as a perennial herb to about 3 feet tall with red flowers May-August, low water use, dry gravelly soils, native from southwestern Colorado and Utah to central Arizona and southwestern California (AZ, CA, CO, NM, NV, UT).

Utah State University Extension lists it for USDA hardiness zones 3-7, full sun to part shade, well-drained low-fertility soil at pH 7.0-8.0, with bright scarlet flowers May to mid-July and high drought tolerance — and warns not to over-water or over-fertilize.

A dry-climate Intermountain West native: the Lady Bird Johnson Wildflower Center notes it is drought tolerant and excellent for dry, gravelly banks and background plantings. Its Plotwright Heat Tier range (Warm–Extreme) is derived per ADR 0021 from this hot, dry, low-water habitat — native from high gravelly Intermountain slopes down into central Arizona and southwestern California, it performs in genuinely hot summers and, like other desert-adapted southwestern natives, tolerates extreme summer heat once established.