Hollyhock (Alcea rosea) is a tall, biennial (sometimes perennial) flowering plant known for its large, showy blooms that grow along towering stalks, reaching up to 8 feet tall. These classic cottage-garden flowers attract bees, butterflies, and hummingbirds, adding vertical beauty to fence lines, borders, and garden backdrops.

How to Grow Hollyhock

Sowing and Germination

• Direct Sowing (Recommended):

  • Sow seeds after the last frost in spring for blooms the following year.
  • In warm climates, sow in late summer or early fall for early blooms the next season.
  • Plant seeds 1/4 inch deep and 12–18 inches apart.
  • Germination occurs in 10–21 days.

• Starting Indoors:

  • Start seeds 8–10 weeks before the last frost for earlier blooms.
  • Transplant seedlings outdoors when they have 2–3 true leaves and temperatures stay above 50°F.

• Soil Requirements:

  • Prefers rich, well-drained, slightly moist soil with a pH of 6.0–8.0.
  • Amend soil with compost or organic matter for better growth.

• Sunlight:

  • Requires full sun (at least 6 hours per day) for best blooming.
  • Can tolerate partial shade, but fewer flowers may develop.

Growing Hollyhocks

Watering:

• Keep soil evenly moist, especially during hot, dry periods.
• Water at the base to prevent rust and fungal diseases.

Mulching:

• Apply a light layer of mulch around plants to retain moisture and suppress weeds.

Fertilizing:

• Use a balanced fertilizer (10-10-10) once per month during the growing season.
• Apply compost or a low-nitrogen fertilizer to encourage flowering.

Staking & Support:

• Tall varieties may need staking to prevent them from bending in strong winds.
• Plant hollyhocks against a fence or wall for natural support.

Pruning & Maintenance:

• Deadhead spent blooms to encourage continuous flowering.
• Cut back stalks to ground level after blooming to promote new growth.
• If overwintering, leave some stalks standing to allow reseeding.

Pest and Disease Management:

• Common Pests: Aphids, Japanese beetles, spider mites—use insecticidal soap or neem oil if needed.
• Diseases: Hollyhocks are susceptible to rust (a fungal disease), causing orange-brown spots on leaves.
  • Prevent rust by ensuring good air circulation and watering at the base.
  • Remove infected leaves and apply a fungicidal spray if necessary.

Fast Facts

• Latin Name: Alcea rosea
• Type: Biennial (sometimes short-lived perennial)
• USDA Zones: 3–9
• Days to Germination: 10–21 days
• Days to Maturity: Blooms in the second year
• Bloom Time: Mid-summer to fall
• Height: 5–8 feet
• Spacing: 12–18 inches apart
• Soil pH: 6.0–8.0
• Flower Colors: Pink, red, yellow, white, purple, black

How and When to Harvest Hollyhock Seeds

• Allow flowers to fade and dry on the plant.
• Once seed pods turn brown, remove them and split open to collect seeds.
• Store seeds in a cool, dry place for up to 3 years.
• Self-seeding plant—leave some seed heads on the plant for natural regrowth.

Hollyhock Special Features

Attracts pollinators (bees, butterflies, hummingbirds)
Tall, dramatic blooms for backdrops & fences
Self-seeds easily, returning year after year
Deer-resistant but may need protection from rabbits

Hollyhocks bring cottage-garden charm with their tall, vibrant blooms. With proper care, they self-seed and return year after year, making them a low-maintenance, high-impact addition to any garden! 🌸🌿