Height 60cm-2.4m (2-8ft)
Planting distance 23-60cm (9-24in)
Flowers mid summer to autumn
Hardy biennials and annuals
Hollyhocks (Althaea species and now classified as Alcea) are old-fashioned garden favourites, their towering spikes of large pink, red, dark crimson, yellow or white, single or double, making a strong impact wherever they are grown. They are well suited to cot-tage gardens, or the back of annual and herbaceous borders, ideally growing behind much shorter plants so their stately magnificence – reaching 2.4m (8ft) – can be fully appreciated. The large, light green leaves are lobed, rough and hairy.
The true species hollyhock (A. rosea) has been superseded by named varieties bearing single or double flowers in mixed or single colours. ‘Chater’s Double’ is a mixture with peony-shaped, double flowers in a variety of colours. ‘Majorette’ is a dwarf variety reaching 60-75cm (24-30in) high with double fringed flowers in a mixture of pastel shades. ‘Nigra’ has single, rich chocolate-maroon flowers and stands 1.5m (5ft) high. ‘Pinafore Mixed’ has semi-double and single fringed flowers in pink, carmine, rose, yellow and white. It reaches 90-100cm (36-40in) high. ‘Powder Puffs’ has double red, pink, rose, white and yellow flowers, and reaches 1.8-2.4m (6-8ft) high. ‘Summer Carnival’ has fully double blooms covering the full length of the 1.5-1.8m (5-6ft) high stems. They come in a wide range of colours. It is an annual so seeds sown in spring produce flowering plants that summer.
Hollyhocks like a heavy rich soil and, preferably, a sheltered site. For biennial plants, sow seeds outdoors in early and mid summer, 23cm (9in) apart. Thin the seedlings to 60cm (2ft) apart in early to mid autumn.
For annual plants, sow under glass in late winter, for planting out in, or sow directly in the final position in mid spring, and thin to 38cm (15in) apart.
Water freely during dry weather, and stake tall varieties in exposed positions. For perennial growth, cut the plants to 15cm (8in) above ground in autumn.
Pests and diseases
Rust, which affects the leaves and stems, is often a problem with older plants -a reason why hollyhocks are best grown as annuals or biennials.