PL. —Alcea roseaBotanical illustration — drop image
Alcea rosea

Hollyhock

Summer
3a9bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Hollyhocks are one of the defining plants of the cottage and cutting garden — towering spikes of large, crepe-paper flowers in shades from white and cream through pink, apricot, red, and near-black, with the distinctive hollyhock silhouette recognisable from a distance. Biennial or short-lived perennial, they bloom most prolifically in their second year and self-seed freely if allowed.

As cut flowers, individual hollyhock blooms are short-lived but the whole spike lasts several days as successive buds open. Cut when the lower third of the spike is in bloom. The stems are hollow — flip upside-down and fill with water before sealing with your thumb to extend vase life.

Care guide
SunFull sun
WaterModerate; tolerates dry spells once established
SoilAverage to rich, well-draining; tolerates clay
Spacing18–24 inches
Height5–9 feet
Zone3a – 9b
Direct sowFrost hardy
Seasonal tasks
spring
sowSow direct in early summer for second-year bloom, or in spring for possible first-year flowering
summer
cutCut spikes when lower third is open; fill hollow stems with water to extend vase life
watchRust appears on lower leaves — remove affected leaves; it rarely kills the plant
fall
watchAllow some plants to set seed for self-sowing colony maintenance
Common problems

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.