Hollyhocks, or Alcea rosea, are classic garden plants known for their towering height and vibrant, cup-shaped flowers that bloom along a central spike. When purchasing hollyhocks, the “roots” typically refer to bare-root divisions or rhizomes, which are dormant, established plant structures. Planting these roots offers a distinct advantage over starting from seed, providing the gardener with a significant head start on the plant’s growth cycle. These plants add vertical interest, often reaching heights of six to eight feet.
Optimal Planting Time
The best time to plant dormant hollyhock roots is determined by local climate and the workability of the soil. Planting can successfully occur in two main seasonal windows: early spring and late autumn. Early spring planting is generally preferred, as it allows the root system to establish itself before the onset of summer heat and drought conditions. This timing should be as soon as the soil is thawed and can be easily worked, often several weeks before the last expected frost date in colder regions.
Planting in late autumn is a viable alternative, especially in areas with milder winters. Roots should be placed in the ground roughly four to six weeks before the first hard freeze is expected. This allows the plant to develop foundational roots while the soil is still relatively warm, ensuring that the plant is poised for immediate growth as soon as spring arrives.
Step-by-Step Planting Guide
Before planting, soak the bare roots in a bucket of water for one to two hours to rehydrate the tissues. The planting site should be prepared by loosening the soil to a depth of 12 to 18 inches, as hollyhocks develop a long taproot that needs ample space to grow downward. Soil composition should be well-drained and moderately fertile; incorporating compost or well-rotted manure into the loosened soil improves structure and nutrient availability.
Dig a hole wide enough to accommodate the entire root system without bending the roots upward. The crown, which is the point where the roots meet the stem, should be positioned right at or slightly above the soil surface. Planting the crown too deeply can lead to rot, while planting too shallowly risks the roots drying out. After positioning the root and backfilling the hole with soil, gently tamp the area to remove large air pockets, and water the plant thoroughly to settle the soil around the roots.
Hollyhocks need to be spaced adequately to allow for good air circulation, which helps prevent disease. A spacing of about 24 to 30 inches between plants is recommended, especially since some varieties can grow quite tall. The ideal location provides full sun exposure, meaning at least six hours of direct sunlight daily, and a sheltered position can help protect the tall flower stalks from strong winds.
First Year Expectations and Care
After planting, consistent moisture is necessary as the roots begin to establish themselves in the soil. Young hollyhocks require regular watering to keep the top six inches of soil damp, but avoid over-watering, which can lead to root suffocation and yellowing leaves. Once the plants are established, they become more tolerant of drier conditions, requiring deep watering primarily during prolonged dry spells.
Hollyhocks are generally biennials, meaning they focus on growing foliage and building a strong root system during their first year of growth. Expecting flowers in the initial growing season may lead to disappointment, as the plant typically reserves its energy for a robust bloom in the second year. Due to their potential height, taller varieties often require staking with bamboo canes or sturdy stakes to prevent the stems from bending or breaking in the wind.
Gardeners should monitor for hollyhock rust, a common fungal disease that appears as orange or reddish pustules on the undersides of leaves. Providing good airflow through proper spacing helps prevent this issue, and removing any infected leaves promptly can limit the spread of the spores. A light application of a balanced, slow-release fertilizer in the spring can encourage better overall growth and support the energy required for flowering.
Distinguishing Roots from Seeds
Planting hollyhock roots provides a significant time advantage over starting the plant from seeds. The roots are already a year or more into the plant’s life cycle, often resulting in flowers appearing in the first or second year after planting. Seeds require a full season of vegetative growth to produce foliage before initiating flowering. Seeds are often sown indoors in mid-spring or directly outdoors in late spring or early summer, producing only a rosette of leaves in the first year.