Hollyhocks are classic garden plants known for their impressive height and vibrant, cup-shaped flowers on tall spikes. Propagating them involves creating new plants from existing material, allowing you to expand your garden or share these charming flowers.
Understanding Hollyhock Propagation
The timing for propagating hollyhocks varies by method. Seeds are typically sown in late summer or early autumn for blooms the following year, or in spring after the last frost. Division of established plants is best done in spring, as are cuttings from new growth.
Propagating Hollyhocks from Seeds
Collect seeds from dried, brown pods. Store them in a cool, dry place if not sown immediately. For starting seeds indoors, fill a seed tray with well-draining seed compost and moisten it. Sow seeds about 0.5 cm deep, or lightly press them onto the surface, as they require light for germination. Maintain a soil temperature between 15-21°C (60-70°F) for optimal germination, which typically occurs within 7-21 days.
Direct sowing outdoors can be done in spring after the last frost or in late summer to early autumn. Prepare a well-drained location with full sun to partial shade by loosening the soil and removing weeds. Scatter seeds over the prepared area or sow them about 0.5 cm deep, spacing them about 60 cm (2 feet) apart. Consistent moisture is important for germination and initial seedling development.
Propagating Hollyhocks by Division
Propagating hollyhocks by division is an option for mature plants, though challenging due to their deep taproots. This method is typically performed in spring when the plant is not actively blooming. Cut back existing foliage to about 10-15 cm (4-6 inches) to reduce plant stress.
Carefully dig around the entire root ball, going deep enough to get most of the taproot. Once lifted, use a sharp knife to divide the taproot into sections, ensuring each has at least one stem and healthy roots. Replant divisions immediately into prepared soil, ensuring roots are covered and the stem base is at the same depth. Water thoroughly to help them establish.
Propagating Hollyhocks from Cuttings
Propagating hollyhocks from cuttings is less common but can be successful, particularly with basal cuttings. These are taken from young, new growth emerging from the plant’s base in spring. Select a healthy stem and cut it as close to the base as possible.
Remove lower leaves from the cutting, leaving a few at the top. Plant the cutting into a pot with well-drained cuttings compost, burying it about 2.5 cm (1 inch) deep. To promote rooting, cover the pot with a clear plastic bag or place it in a propagator. Roots should develop within a few weeks, indicated by new leaf growth, at which point the cover can be removed.
Caring for Young Hollyhock Plants
Young hollyhock plants, whether from seed, division, or cuttings, require consistent care to establish. They thrive in full sun, needing at least six hours of direct sunlight daily; some afternoon shade is beneficial in hotter climates. Well-draining soil is important, and amending it with compost provides nutrients.
Water seedlings and young plants regularly to keep the top 12-15 cm (5-6 inches) of soil consistently moist, avoiding overwatering. Water at the plant’s base to prevent fungal diseases like rust. If seedlings were started indoors, gradually expose them to outdoor conditions over one to two weeks (hardening off) before transplanting them to their final garden spot.