25 Seeds Double Blackberry Hollyhock Alcea Rosea Deep Purple Black Double Blooms Biennial Tall Cottage Garden

These Double Blackberry Hollyhock seeds produce dramatic deep purple-black, fully double flowers on tall, sturdy stalks. This Alcea rosea variety is a cherished cottage garden classic, adding old-fashioned charm and vertical interest to sunny borders.

Excellent for cut flower arrangements and as a backdrop for shorter perennials, these biennial plants typically bloom in their second year. They thrive in full sun and well-drained soil, reaching heights of up to 8 feet. Provide support in windy locations and deadhead spent blooms to encourage continued flowering.

Species: Alcea rosea
Variety: Double Blackberry
Type: Flower seed
Plant_Habit: Tall single stalk
Sun: Full sun
Soil: Well-drained, moderately fertile
Days_to_Harvest: Not applicable
Zones: 3-9
Germination: 10-20 days at 60-70°F (15-21°C)
Sowing: Sow seeds indoors 6-8 weeks before last frost or direct sow in early spring or fall; press onto soil surface as light is needed for germination
Spacing: 18-24 inches
Notes: Biennial; flowers in second year; may require staking