Pro tips for growing hollyhocks

Hollyhocks are legendary among perennials, famed for their 1.5 metre (five foot) height, 10-centimetre-wide (four-inch-wide) flowers and broad colour range. But the main reason hollyhocks have endured is their easy-to-please nature. These are survivors that return season after season for enthusiastic encores. Here are some pro tips to help you add hollyhocks to your outdoor space.

• Set out seedlings in spring or early fall in a sunny spot and in soil fortified with compost or rotted manure. Set plants 60 centimetres (25 inches) apart and group them in trios.
• Water during dry weather to prevent wilting and fertilize twice during the growing season with a balanced fertilizer applied per package directions.
• In late spring, stake flower spikes to 1.8 metre (six foot) poles to keep them from blowing over in wind, a crucial step when growing the big double-flowered varieties.
• Cut off the spires after the flowers are spent. Sometimes plants rebloom on new, shorter spikes. Leave some old flowers at the bottom to ripen a new batch of seeds.
• Gather and plant the seeds after they turn black in fall, or store them in an envelope and plant them outdoors in spring.
• Where summers are long and hot, you may get best results growing varieties such as biennials, which are sown in fall for flowering the next spring and are not expected to return thereafter. However, given a chance, hollyhocks will persist as a perennial.

• A fungal disease called rust, which leaves orange, powdery deposits on leaves, can be a problem. Fig hollyhock (Alcea ficifolia) shows good resistance. If problems arise with other varieties, remove and dispose of affected leaves.
• If tiny, sap-sucking spider mites make webs on leaf undersides, spray the foliage with a stream of water or treat them with insecticidal soap per label directions.
• Japanese beetles may chew leaves and flowers. Handpick and dispose of them in the morning when the beetles are sluggish, or apply a botanical insecticide as directed.
• The beetles feed mostly in sun, so try growing hollyhocks in partial shade.
• If deer nibble plants, tuck a bar of deodorant soap into clumps to repel them, or use commercial repellent as directed.

Hollyhocks are generally short-lived but easy to grow from seed.

• Place hollyhocks anywhere you need a strong vertical statement. With their upright stance and dramatic flower spikes, hollyhocks are unsurpassed as backgrounds in a flower border, enhancing a wall or fence or for sidling up to an arbour or gate.