Use straw compost leaf litter or mulch. They also tend to stick together. How To Grow Hollyhocks Hollyhock Growing Guide Growing In The Garden Hollyhocks Flowers Garden Care Growing Hollyhocks Transplant hollyhock seedlings or container grown plants to the garden flower border after the last frost. How to care for hollyhock . In early spring gradually start pulling a layer away to acclimate the roots to the changing season. Propagation care for Hollyhock HollyhockHollyhock multi-purpose sowing method propagation can be carried out in spring or autumn. The south to autumn sowing as well as the north to spring sowing. If you are planting seeds sow the seeds outside about a week before last frost. Just improve the soil by adding a 10cm 4in layer of well-rotted garden compost to the soil where you wish to grow the hollyhocks and digging it in before planting. Shows different stages of growth and when to expect blooms. For early flowers start annual hollyhocks indoors ...