Penstemon
Penstemon spp. and hybrids
Penstemons produce spikes of tubular, foxglove-like flowers in red, pink, purple and white from early summer to fall. Native American species suit dry gardens, while UK-bred hybrids flower for months in borders.
Photo: Patrick Alexander https://www.inaturalist.org/people/aspidoscelis · CC0, via Wikimedia Commons
Essential Care Requirements
Light
Full sun
Watering
Low
Water in dry spells; avoid wet soil in winter.
Soil
Well-drained, gritty soil; pH 6.0–7.5.
Temperature and humidity
-20–35 °C · Low humidity
Feeding
Light feeding in spring.
Pruning and propagation
Propagate by stem cuttings, seed, division
Deadhead through summer; leave stems over winter and cut back in spring.
Penstemons are not toxic.
Top Cultivation Tips
Take cuttings in late summer as insurance against hard winters.
Hummingbirds love the red types.
Narrow-leaved types are hardier.
Hardy in USDA zones 4–9 depending on species.
Common problems
Powdery mildew
A fungal disease that coats leaves, buds and young shoots with a white, flour-like dust, weakening the plant and spoiling flowers and fruit.
How to treat it →DiseaseRoot rot
Roots decay in waterlogged soil, so the plant wilts and yellows even though the soil is wet.
How to treat it →
