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yellow penstemon

Penstemon confertus · Scrophulariaceae

yellow penstemon (Penstemon confertus)
Photo: (c) Doug Macaulay, some rights reserved (CC BY) · CC BY · via iNaturalist

yellow penstemon (Penstemon confertus) is a perennial herbaceous plant in the Scrophulariaceae family. It is native to North America. USDA records it as hardy in zone 4 and warmer, down to about -23°F.

At a glance

Typeforb-herb Derived
Lifecycleperennial USDA
Native statusnative USDA
Mature height2 ft USDA
Lightshade USDA
Water needmedium USDA
Growth raterapid USDA
Soil pH6–7.5 USDA
BloomJuly USDA
Flower colorYellow USDA
Hardiness zones4 and warmer USDA
Guild layerherb-layer Derived
Nursery availabilityNo Known Source 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 tolerates full shade. USDA rates it as having moderate water needs. Its drought tolerance is rated low. It will not tolerate waterlogged soil — USDA rates its anaerobic tolerance as none. It is recorded on soils from pH 6 to 7.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 4.

Size and growth

At maturity it reaches about 2 ft, making it about knee height. It grows quickly.

Bloom period

USDA records a bloom period of July. Flowers are yellow.

A flowering date, not a pollinator rating.

Foliage, flower and season

Summer foliage is green, fine 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 moderate.

What the site needs to provide

USDA records it across sites receiving 15 to 65 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 120 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 rapid 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 single crown.

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.

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Tags

deciduoushedgeclay-tolerantsandy-soilnativeshade-tolerantfast-growing

Related plants

Others in Penstemon

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol PECO6, 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.

Read our full data sources and methodology.

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