Common Hollyhock
alcea biennis
Also known as: ["Hollyhock","Wild Hollyhock"]
Overview
A tall biennial plant with showy, hibiscus-like flowers in shades of pink, yellow, or white, native to Europe and Asia.
Benefits & Perks
["long-flowering","wildlife attractant (bees, butterflies, birds)","aesthetic foliage"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Malvales |
| Family: | Malvaceae |
| Genus: | Alcea |
| Botanical Name: | Alcea biennis |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: garden bed or border, prefers open spaces
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"5–35°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. Tolerates poor soils but thrives with enrichment.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: moderate
- Pruning Frequency: Deadhead spent flowers throughout the growing season; prune lightly in early spring if needed.
- Pruning Intensity: Light to moderate. Avoid heavy pruning unless rejuvenating an older plant.
Care Details
Ideal Sunlight Coverage:
Full sun (6–8 hours of direct sunlight daily). Tolerates partial shade but may produce fewer flowers.
Sunlight Tolerance Tips:
Acclimate plants gradually if moving from shade to sun; protect from intense midday heat in hot climates; ensure good air circulation to prevent mildew in humid conditions.
Care Requirements
Care Difficulty
easyeasy
Sunlight
full sun to partial shade
Rotate plants for even growth; use shade cloth in extreme heat; avoid placing in drafty areas.
Watering
every 7–10 days during active growth, less frequently in winter
Water thoroughly but infrequently to encourage deep roots; ensure soil dries slightly between waterings; avoid overhead watering to prevent leaf diseases.
Soil
well-drained, moderately fertile soil
pH: Slightly acidic to neutral (pH 6.0–7.0).
Avoid heavy clay soils; ensure good aeration; mulch to retain moisture and suppress weeds.
Temperature
Prefers cool to moderate temperatures (60–75°F or 15–24°C). Tolerates cooler nights and can survive light frosts.
Avoid sudden temperature fluctuations; protect from frost; ensure good ventilation in hot weather.
Fertilizing
every 4–6 weeks during growing season
Avoid over-fertilizing to prevent root burn; fertilize before new growth appears; flush soil occasionally to prevent salt buildup.
Propagation
Methods
Seed propagation is most common and reliable. Stem cuttings can also be used but are less common.
Step-by-Step Propagation Guide
- Sow seeds shallowly or take 4–6 inch cuttings.
- Keep moist and warm.
- Transplant once established.
Best Time: Spring or early summer when the plant is actively growing.
Environment
Warm (65–75°F or 18–24°C), humid, and bright but indirect light. Protect from drafts.
Medium
Well-draining seed starting mix or a mix of peat and perlite for cuttings.
Hormone
Not necessary for seeds; rooting hormone can help with stem cuttings.
Timeline
Seeds germinate in 2–4 weeks; cuttings root in 3–6 weeks and may take a full season to establish.
Tools Needed
Seed trays, pruners, rooting hormone (optional), misting bottle, heat mat (optional).
Quick Tips
Use fresh seeds for best germination; bottom heat can speed up rooting; harden off seedlings before planting outdoors.
Pruning & Repotting
Pruning Guide
Method
Pinch back tips to encourage branching; cut spent flower stalks at the base; trim leggy growth to shape the plant.
Pruning Plan
Prune to maintain shape, encourage bushier growth, and remove spent flowers to prolong blooming.
Tools
Hand pruners, clean scissors, gloves.
Checklist
Clean tools before use; prune dead or damaged growth; remove spent flowers; shape as desired.
Repotting Guide
Best Season
Early spring before new growth begins.
Pot Size
Choose a pot one size larger (1–2 inches wider in diameter) than the current one.
Method
Remove the plant gently, trim any circling roots, place in a new pot with fresh soil, and water thoroughly.
Suggestions
Repot only if the plant becomes root-bound or outgrows its container. Generally, every 2–3 years is sufficient.
Checklist
Select appropriate pot size; prepare fresh soil mix; trim roots if necessary; water after repotting.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply at the base; ensure proper drainage; adjust frequency seasonally.
How to Apply Water Properly
Water directly at the root zone until the soil is evenly moist but not waterlogged. Ensure water penetrates the root ball deeply and allow excess to drain away. Water in the morning to minimize evaporation and fungal growth.
Watering Schedule Tips
Water deeply once per week during active growth, reducing frequency in winter to every 2–3 weeks. Adjust based on rainfall and soil moisture retention.
Soil Improvement
Add compost or well-rotted manure to enhance fertility and structure; incorporate perlite or sand for drainage.
Temperature Stress Management
Signs of Temperature Issues
Wilting, yellowing leaves, stunted growth, or flower bud drop in extreme heat or cold.
Cold Stress
Slows growth and may cause leaf discoloration or dieback in prolonged freezing temperatures.
Solution: Mulch heavily around the base in winter; move potted plants to a sheltered location; avoid overwatering in cold conditions.
Hot Stress
Leaves may wilt, scorch, or drop; flowering may cease in excessive heat.
Solution: Provide afternoon shade; increase watering frequency; use mulch to retain soil moisture; improve air circulation.
Fertilizing Guide
Fertilizing Checklist
Use balanced fertilizer; apply at half-strength for young plants; avoid fertilizing dormant plants.
Fertilizing Method
Use a balanced, slow-release fertilizer in early spring. Apply a diluted liquid fertilizer monthly during the growing season, reducing or stopping in fall and winter.
Common Problems & Solutions
Toxicity Warning
Cats
Non-toxicAlcea biennis is not considered toxic to cats. The plant does not contain any known compounds that are harmful to felines. However, ingestion of large amounts may cause mild gastrointestinal upset due to the plant's fibrous nature.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if ingested
Dogs
Non-toxicAlcea biennis is not considered toxic to dogs. The plant does not contain any known compounds that are harmful to canines. However, ingestion of large amounts may cause mild gastrointestinal upset due to the plant's fibrous nature.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if ingested
Humans
Non-toxicAlcea biennis, commonly known as the common hollyhock, is generally considered non-toxic to humans. However, ingestion of large quantities of seeds may cause mild gastrointestinal discomfort due to the presence of mucilage and other plant compounds. The plant is not known to produce any significant toxic effects on human physiology.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten in large quantities
Frequently Asked Questions
Q: Is Alcea biennis an annual or perennial?
A: It is a biennial plant, meaning it completes its life cycle over two years.
Q: Does Alcea biennis attract pollinators?
A: Yes, it is known to attract bees, butterflies, and other pollinators.
Q: How tall does Alcea biennis grow?
A: It typically grows to heights of 5-9 feet.
Quick Reference
| Family: | Malvaceae |
| Care: | easy |
| Light: | full sun to partial shade |
| Water: | every 7–10 days during activ |
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