Whipple's penstemon
Penstemon whippleanus · Scrophulariaceae
Whipple's penstemon (Penstemon whippleanus) is a perennial herbaceous plant in the Scrophulariaceae family. It is native to North America. USDA records it as hardy in zone 3 and warmer, down to about -34°F.
At a glance
| Type | forb-herb Derived |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Mature height | 3 ft USDA |
| Light | part-shade USDA |
| Water need | medium USDA |
| Growth rate | rapid USDA |
| Soil pH | 7–8 USDA |
| Bloom | August–September USDA |
| Flower color | Purple USDA |
| Hardiness zones | 3 and warmer USDA |
| Guild layer | herb-layer Derived |
| Nursery availability | Contracting Only USDA |
USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.
Growing conditions
It grows in partial shade. USDA rates it as having moderate water needs. Its drought tolerance is rated medium. It will not tolerate waterlogged soil — USDA rates its anaerobic tolerance as none. It is recorded on soils from pH 7 to 8 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 3.
Size and growth
At maturity it reaches about 3 ft, making it roughly waist to chest height. It grows quickly.
Bloom period
USDA records a bloom period of August through September. Flowers are purple.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, medium in texture. Its flowers are conspicuous. Its fruit or seed heads are conspicuous, extending interest past flowering. Its active growth period is spring and summer. USDA rates its lifespan as short, so plan on replacing or resowing it rather than treating it as permanent structure.
What the site needs to provide
USDA records it across sites receiving 13 to 35 inches of annual precipitation. The low end of that band is genuinely arid, so it has a wide tolerance for dry country. It needs at least 117 frost-free days to finish its season. It roots to at least 6 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.
Propagating it
Propagate it from seed and container stock. Seed needs cold stratification — a period of moist chilling — before it will germinate, so sow in autumn or chill it artificially before a spring sowing. Its seed spreads at a moderate rate. It does not spread vegetatively, so it will stay where you put it.
Resilience and wildlife
Browsing animals find it highly palatable, so expect deer and rabbits to take an interest. Its fire tolerance is rated high. Its growth form is recorded as multiple stem.
Role in a guild
Herb layer. In a layered planting this is the herbaceous middle — perennials and grasses that fill the space between ground cover and shrubs. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Penstemon
- sharpleaf penstemon Penstemon acuminatus
- Alberta beardtongue Penstemon albertinus
- broadbeard beardtongue Penstemon angustifolius
- yellow penstemon Penstemon confertus
Similar role and hardiness
- common maidenhair Adiantum capillus-veneris
- winter bentgrass Agrostis hyemalis
- European water plantain Alisma plantago-aquatica
- showy milkweed Asclepias speciosa
- butterfly milkweed Asclepias tuberosa
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol PEWH, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.
- Quoted from USDA PLANTS: active growth period, Bloom, Bloom end, browse palatability, cold stratification, Drought tolerance, fall conspicuous, fertility requirement, fire tolerance, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, growth form, Growth rate, Hardiness zones, Lifecycle, lifespan, Light, Mature height, Minimum temperature, Native status, Nitrogen fixation, Nursery availability, precipitation max in, precipitation min in, propagation, resprout ability, root depth in, seed spread rate, Soil pH, Soil pH (upper), Tolerance of wet soil, Toxicity, vegetative spread rate, Water need.
- Derived by a fixed rule from those columns: Guild layer, Type.
Read our full data sources and methodology.
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