Foxglove Beardtongue
penstemon digitalis
Also known as: ["White Foxglove","White Penstemon"]
Overview
A herbaceous perennial native to North America, known for its upright stems and tubular white flowers.
Benefits & Perks
["long-flowering","wildlife attractant (bees, butterflies, birds)","drought tolerant","aesthetic foliage"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Lamiales |
| Family: | Plantaginaceae |
| Genus: | Penstemon |
| Botanical Name: | Penstemon digitalis |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: garden bed or container in a location with good air circulation
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"–30–40°C"}
- Hardiness: {"zones":"3–9"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Fast-draining to prevent root rot.
- Soil Type: Well-draining loamy soil with added organic matter; avoid heavy clay.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: moderate
- Pruning Frequency: After flowering and as needed to remove dead or damaged stems.
- Pruning Intensity: Light to moderate; avoid heavy pruning unless rejuvenating an older plant.
Care Details
Ideal Sunlight Coverage:
Full sun (6–8 hours/day) with some afternoon shade in hot climates; adjust for seasonal light changes.
Sunlight Tolerance Tips:
Acclimate gradually to intense sun, protect from harsh afternoon rays, and ensure proper ventilation if indoors.
Care Requirements
Care Difficulty
easymoderate
Sunlight
full sun to partial shade
Rotate plant for even light, use sheer curtains in intense sun, avoid direct midday exposure.
Watering
every 7–10 days during active growth, reduce in winter
Water at the base, avoid wetting foliage, and ensure soil dries slightly between waterings.
Soil
well-draining, loamy soil with moderate organic matter
pH: Slightly acidic to neutral (pH 6.0–7.0).
Use raised beds for better drainage, avoid overwatering, and test soil pH annually.
Temperature
Prefers 65–75°F (18–24°C); tolerates cooler nights but avoids extreme heat or frost.
Avoid sudden temperature shifts, protect from drafts, and maintain consistent warmth during active growth.
Fertilizing
every 4–6 weeks during spring and summer
Fertilize only when actively growing, flush soil occasionally to prevent salt buildup, and stop before dormancy.
Propagation
Methods
Stem cuttings or seed; stem cuttings are faster and more reliable for home growers.
Step-by-Step Propagation Guide
- Take 4–6 inch cuttings, remove lower leaves, dip in hormone, plant in medium, keep moist and humid.
Best Time: Late spring to early summer when the plant is actively growing.
Environment
High humidity (70–80%), indirect light, and consistent warmth (65–70°F).
Medium
Well-draining mix of perlite and peat moss or cactus mix.
Hormone
Recommended to use rooting hormone for faster and more reliable rooting.
Timeline
Roots develop in 3–4 weeks; new growth appears in 6–8 weeks.
Tools Needed
Pruners, rooting hormone, small pots, misting spray bottle, plastic bags or propagator.
Quick Tips
Use healthy, non-flowering stems, maintain humidity with a plastic cover, and avoid direct sunlight.
Pruning & Repotting
Pruning Guide
Method
Deadhead spent blooms, trim back to healthy growth, and shape as desired.
Pruning Plan
Remove spent flowers to encourage reblooming and cut back leggy growth to maintain shape.
Tools
Clean pruners or scissors, gloves, and disinfectant for tools.
Checklist
Sanitize tools, deadhead flowers, trim leggy stems, inspect for pests/disease.
Repotting Guide
Best Season
Early spring before new growth begins.
Pot Size
Increase pot size by 2–3 inches in diameter; avoid oversized pots.
Method
Use fresh well-draining soil, trim rootbound roots, ensure proper drainage, and water lightly after repotting.
Suggestions
Repot every 2–3 years or when roots fill the container; beneficial for growth and health.
Checklist
Prepare new pot, remove plant gently, trim roots if needed, add fresh soil, water lightly.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture, water deeply, ensure drainage, adjust seasonally.
How to Apply Water Properly
Water thoroughly until it drains from the bottom, ensuring root zone saturation while avoiding waterlogging.
Watering Schedule Tips
Water deeply once a week during active growth, reducing frequency in winter; adjust based on rainfall and soil moisture.
Soil Improvement
Add perlite or coarse sand for drainage, incorporate compost for fertility, and ensure aeration with organic matter.
Temperature Stress Management
Signs of Temperature Issues
Wilting, leaf scorch, stunted growth, or bud drop in extreme conditions.
Cold Stress
Slows growth, may cause leaf discoloration, and can lead to root damage in freezing temperatures.
Solution: Provide frost protection, move indoors in winter, and ensure well-drained soil to prevent root rot.
Hot Stress
Leaves may wilt, curl, or develop brown edges; flowering may be reduced.
Solution: Provide afternoon shade, increase watering, and use mulch to retain soil moisture.
Fertilizing Guide
Fertilizing Checklist
Check growth phase, dilute fertilizer, apply to soil, avoid foliage contact.
Fertilizing Method
Use balanced liquid fertilizer diluted to half strength every 4–6 weeks during spring and summer; avoid winter feeding.
Common Problems & Solutions
Toxicity Warning
Cats
Non-toxicPenstemon digitalis is not known to be toxic to cats. There are no documented cases of adverse effects in felines after ingestion.
⚡ Toxic If:
if eaten
Dogs
Non-toxicPenstemon digitalis is not known to be toxic to dogs. There are no documented cases of adverse effects in canines after ingestion.
⚡ Toxic If:
if eaten
Humans
Non-toxicPenstemon digitalis is generally considered non-toxic to humans. There are no known toxic effects or physiological impacts associated with this plant.
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: How tall does Penstemon digitalis grow?
A: It typically reaches 2–3 feet in height.
Q: Does it require full sun?
A: Yes, it thrives in full sun to partial shade.
Q: When does it bloom?
A: It blooms in late spring to early summer, producing white flowers.
Quick Reference
| Family: | Plantaginaceae |
| Care: | easy |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during activ |
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