This single hollyhock is about as close as a flower can get to really black, a deep, deep, purple it is very decorative and an excellent counterpoint in arrangements. While technically a biennial, hollyhock plantings last for decades as a result of division and self-seeding.
Biennial, zone 3-8
Germination: 10-21 days
Germination Temperature: Optimum soil temperatures 60-70ºF
Seed Planting Depth: Sow on the surface and lightly cover, seeds need some light to germinate
Starting Indoors: Start indoors 6-8 weeks before the last frost. Provide 60-70ºF soil temperature. Transplant after last frost, 18-24” apart
Sowing Outdoors: Direct sow after the last frost or in the fall
Growth Habit: Columnar
Height and Width: 48-60" by 12-18"
Spacing: 12-24" apart
Light Needs: Full sun to part shade
Soil Needs: Fertile, moist, well-drained
Approximate days to flower from seed: Blooms in the second season
Uses: Cut flowers, back border of the flower garden, cottage gardens, attracts pollinators
Care: Water seedlings regularly until established. Amend soil with compost before transplanting. Cut back stems as the blooms fade, this encourages more flower production. Leave some seed pods on the plant of you would like it to self-seed.