When to plant
Plant Alcea (hollyhocks) in spring or early summer, after the risk of hard frost has passed. In colder climates you can start young plants under cover and transplant them once the soil has warmed. They are typically biennial or short-lived perennials but will often self-seed and return in following years.
Where to plant
Choose a sunny, open spot with at least 6 hours of direct sun per day. Alcea are perfect for the back of borders, along fences or walls, or as a cottage-garden accent. Avoid very exposed, windy sites unless you’re prepared to stake them, as the tall flower spikes can catch the wind.
Preparing the soil
Loosen the soil to a depth of around 25–30 cm and mix in compost or well-rotted manure to improve fertility and drainage. Hollyhocks prefer well-drained, moderately rich soil; heavy clay can be lightened with coarse sand or grit, while very sandy soil benefits from extra organic matter to hold moisture.
Preparing the plants
If planting bare-root Alcea, soak the roots in a bucket of water for 30–60 minutes before planting so they rehydrate fully. For potted plants, water them well and gently tease out any circling roots to encourage them to spread into the surrounding soil.
Planting the plants
Set plants so that the crown (where stems meet roots) sits at soil level. Space them about 40–60 cm apart to give room for tall stems and good air circulation. Firm the soil gently around the roots and water thoroughly to settle everything in.
After planting
Keep the soil evenly moist while plants establish, especially in their first growing season. A light mulch of compost or leaf mould around (but not touching) the stems helps conserve moisture and suppress weeds.
During growth
As flower spikes elongate, stake taller varieties if your garden is windy, tying stems loosely to canes or discreet supports. Water in dry spells, but avoid overwatering or waterlogging. To reduce the risk of rust (a common hollyhock disease), water at the base rather than over the foliage and ensure plants are not overcrowded.
After flowering
Remove spent flower spikes down to a low leafy section to encourage side shoots and, sometimes, a second flush of blooms. If you want them to self-seed, leave a few seed heads to ripen and scatter. In late autumn, cut back dead stems to just above ground level and clear away any heavily diseased foliage.
Extra tips
Alcea look best planted in informal groups or drifts rather than as single plants. Combine them with lower perennials to hide their bare lower stems. To keep a good display year after year, allow some plants to self-seed and thin out excess seedlings in spring, keeping the strongest in well-spaced clumps.
