All about growing Hollyhocks from seed

Growing Guide

Hollyhocks are easy to grow and their blooms come in a wide range of jewel colours, flowering from early summer to autumn. Their tall spires look good grown against walls and fences and are stalwarts of cottage gardens. At the base is a clump of large, round, mid-green leaves. The perfect plant for the rear of borders where it will rise up to 5 foot, and more.

Sow Hollyhock indoors in from January to March or July to September. Sow seed thinly on the surface of a good quality seed compost, lightly cover with compost or vermiculite and keep moist. These seeds may benefit from gentle heat to encourage germination, often a windowsill will be sufficient, but if sowing over summer the greenhouse or a cold frame will suffice. Initially, water the seeds from below and keep the soil damp but not wet and do not exclude light. Place in a propagator or seal the seed tray inside a polythene bag until after germination. When seedlings are large enough to handle, transplant and grow them on in cooler conditions until large enough to plant outdoors.

When Spring sown Hollyhock plants are well grown and all risk of frost has passed, acclimatise them to outdoor conditions over 7 to 10 days and plant out. For summer sown plants, ensure they are in the ground whilst it is still warm and they have a chance to establish before the frosts.

  • Key Information

    Height: to 180cm

    Spread: to 50cm

    Hardy perennial

    Full sun

    Germination: 5 - 10 days

  • Sowing & Growing Schedule

    Sow Indoors:  January to March, July to September

    Sow Outdoors:  n/a

    Plant Out:  April to June, October

    Blooms:  June to September

  • Varieties we recommend

    Bright Lights

    Black Knight

Top Tip

Hollyhocks are fully hardy and don’t require any special treatment over winter. Remove all dead leaves and discard plants that have been badly effected by rust disease which Hollyhocks can be susceptible to. This is easy to spot as the leaves and stems will be covered in orange-brown spots. Remove infected leaves as soon as you spot them and burn them.