Alcea rosea, commonly known as Hollyhock, is a tall and showy biennial or short-lived perennial plant that belongs to the mallow family. Native to Asia and Europe, it has been widely cultivated in gardens around the world for its beautiful flowers. The plant can grow up to 6 feet tall and features a single stem with large, slightly hairy, heart-shaped leaves.
The flowers of Alcea rosea are large and showy, coming in a range of colors including pink, red, yellow, white, or purple. They bloom from mid-summer to early fall on long spikes that can reach up to 8 feet tall. These flowers attract bees and butterflies, making Hollyhocks an excellent choice for pollinator gardens.
Hollyhocks prefer full sun exposure and well-drained soil but can tolerate partial shade. They require regular watering during dry spells, though they do not favor wet soil, which can lead to root rot.
Medicinally, the plant has been used for centuries due to its anti-inflammatory properties, which make it useful in treating sore throats and respiratory infections when brewed into tea.
Overall, Alcea rosea is a garden favorite that is easy to grow, thanks to its stunning blooms that add both height and color to any garden setting. Additionally, its ability to attract pollinators makes it an excellent choice for gardeners seeking a low-maintenance yet beautiful addition to their garden space.
Hollyhock is fairly resistant to disease and typically does not suffer from illnesses. However, it can be vulnerable to pests and diseases present in its surroundings. These infections are generally not serious. In terms of care, this plant needs moderate maintenance. It should be pruned regularly to maintain a good appearance and healthy growth. Fertilizing can also encourage flowering. Hollyhock is suitable for anyone with outdoor space, such as a garden or patio, and does not demand extensive care experience. It may require additional attention when grown indoors.
How to keep Alcea Rosea.
Light
Hollyhock, a native plant of bright natural habitats, generally does best in locations that receive plenty of sun but can also tolerate areas with moderate sunlight. This adaptable plant may show stunted growth if the light it receives is either too little or too much.
Water
Common hollyhock thrives in temperate regions and requires moderate moisture. To support its growth and flowering, it needs consistent weekly watering. Mulching is beneficial because it helps retain soil moisture, which can reduce the frequency of watering while aligning with the plant's natural water needs.
Humidity
This plant will thrive in moderate humidity, which is probably the level in your home. However, misting it a few times a week can be very beneficial. Make sure the room has good ventilation.
Temperature
Hollyhock originates from regions with temperatures between 68 and 95 °F (20 to 35 °C). It prefers warm summers and mild winters. However, to ensure healthy growth, temperature adjustments—such as providing shade during very hot summers—may be required.
Fertilizer
The best time to fertilize a Hollyhock is in early spring, as it comes out of dormancy and begins active growth. Fertilizing supplies essential nutrients for healthy development. Although Hollyhock has relatively low fertilizer requirements, an annual application can improve its survival and encourage better, longer-lasting blooms.
Pruning
Common hollyhocks are known for their tall spikes and vibrant blooms. To keep them healthy and promote growth, it's important to prune them from early to late spring. Start by removing any damaged stems and trimming off spent flowers. At the end of the season, cutting back the plants can help prevent diseases. Regular pruning also improves airflow, reduces fungal problems, and enhances the plant's overall vigor and flowering capacity.
Pot & Repot
When repotting Hollyhock, select a pot 1–2 inches (2.5–5.1 cm) larger that has ample drainage. Use a well-draining potting mix. Repot in spring or fall, making sure the root ball is slightly lower than the rim of the flower pot. Water thoroughly after repotting and place the plant in a warm spot with indirect sunlight.
Toxicity
The University of California classified hollyhocks as a plant that does cause skin irritation or dermatitis in some people. Hollyhocks are typically not thought to be poisonous to dogs, cats, or people, according to the ASPCA. The University of California classified hollyhocks as a plant that does cause skin irritation or dermatitis in some people.
Further reading →
The toxicity and danger assessments provided are for reference only. We do not assure their accuracy, so it's crucial not to depend on them. Seek professional advice when necessary for accurate guidance.
Botanical profile.
- Plant Type
- Herb
- Life Cycle
- Perennial, Biennial, Annual
- Genus
- Alcea
- Family
- Malvaceae
- Hardiness Zone
- 2-10
- Mature Height
- 1.52 m to 2.44 m
- Mature Spread
- 49 cm to 91 cm
- Leaf Color
- Green
- Leaf Type
- Deciduous
- Flower Color
- Pink, White, Red, Yellow, Purple
- Flower Size
- 5.08 cm to 10.16 cm
- Bloom Time
- Early summer, Mid summer
- Planting Time
- Spring
- Harvest Time
- Mid summer
- Native Area
- China
Other names.
Reader questions.
When Should I Water My Common Hollyhock?
Watering common hollyhock properly is crucial for its health, affecting everything from growth to disease resistance. The best time to water common hollyhock is when the top 1 to 2 inches of soil feels dry to the touch. If the soil is dry, it indicates the plant needs water. Pay attention to the plant's leaves for signs of over or underwatering; yellow leaves might suggest overwatering, while brown or crispy leaves indicate underwatering. Wilting leaves often signal the need for water, but could also mean the plant has been overwatered. Inconsistent watering can lead to various problems such as stunted growth, susceptibility to pests, and diseases, or in extreme cases, plant death. Slow growth might also indicate inadequate water. Regular monitoring and adjusting your watering practices according to these signs can help maintain a healthy common hollyhock.
When should I not put fertilizer on my Common hollyhock?
To properly care for your Common hollyhock, it is best to fertilize it only in late winter or early spring. This plant doesn't require frequent fertilization, so a single annual feeding is enough. Overfertilizing during spring, summer, and fall can lead to complications, unless you skipped fertilizing in spring, in which case it's okay to feed it in the fall. Additionally, there is no need to fertilize the Common hollyhock during winter, as it goes into a dormant growth phase and does not grow. Therefore, fertilizing during most of the winter is not recommended.
What are the sunlight requirements for Common Hollyhock (Alcea rosea)?
Common Hollyhock (Alcea rosea) thrives in areas that receive ample sunlight. It requires full sun, which means it needs more than 6 hours of sunlight daily, but it can also grow in partial sun, with about 3-6 hours of sunlight. When selecting a spot for your Common Hollyhock, observe how sunlight moves through your garden to ensure that you provide an ideal balance of light and shade, ensuring the plant's happiness and health.
What is the indigenous temperature range for common hollyhock?
Common hollyhock, or Alcea rosea, is indigenous to areas that experience temperatures ranging between 68 to 95 °F (20 to 35 °C). This plant thrives in conditions of warm summers and mild winters, indicating its preference for warmer climates. Even though it has a strong resistance to cold, adaptations such as providing shade during extremely hot summers are beneficial for its growth.
How Should I Water My Common Hollyhock?
Common hollyhock thrives with specific watering practices due to its susceptibility to root rot and fungal diseases. The best method for watering common hollyhock is bottom-watering, which allows water to be absorbed from the bottom up, keeping the soil moist without saturating the top unnecessarily. This technique minimizes the risk of fungal diseases. If using a watering can, opt for one with a narrow spout to direct water straight to the base of the plant, minimizing wetting the foliage and thus reducing disease risk. Water at the base promotes root health and contributes to the overall vigor of the plant.
Why should I add fertilizer to my Common hollyhock?
Fertilization is important for the Common hollyhock because it provides essential nutrients for growth. Despite having relatively low fertilization needs, annual fertilization can greatly benefit the plant, keeping it alive and improving flower quality and longevity. Therefore, those wanting their Common hollyhock to thrive should prioritize regular fertilization.
How does Common Hollyhock respond to different sunlight exposures?
Common Hollyhock generally performs best in locations with a lot of sun exposure but can also adapt to moderate sun. If the plant receives too little or too much sunlight, its growth might be affected negatively. In cases where natural sunlight is insufficient, especially during winter or in less sunny spaces, artificial lighting can be a viable option to ensure optimal growth. LED lights are recommended for their ability to provide specific wavelengths needed by plants. Full sun plants require 30-50W/sq ft of artificial light, partial sun plants need 20-30W/sq ft, and full shade plants need 10-20W/sq ft. The artificial light source should be placed 12-36 inches above the plant for 8-12 hours per day to mimic natural sunlight conditions.
How should common hollyhock be protected during winter?
Common hollyhock is notable for its cold resistance and doesn't typically require special frost protection measures during winter. However, in regions where winter temperatures are expected to plummet below -40°C, taking steps to protect the plant is crucial. This involves covering the plant with insulating materials like soil or straw. Additionally, it is recommended to water the plant abundantly before the first freeze of autumn to ensure the soil remains moist and enters winter in a frozen state, thus helping to prevent drought and water scarcity during the colder months.
How Much Water Does Common Hollyhock Really Need?
The amount of water needed for common hollyhock depends on various factors such as the plant size, pot size, and root depth. With its deep taproot, common hollyhock should be watered deeply, ensuring water reaches 2-3 feet below the surface to match the root depth. Typically, watering when the top inch of soil dries out is recommended, with an average session involving 1 to 2 liters of water per plant. Proper hydration results in healthy leaves and abundant flowering. Overwatering and underwatering present risks like root rot or stunted growth, so adjusting the amount based on the plant's condition and environmental factors is key. Ensuring good drainage and observing the plant's response to watering will guide in providing the right amount of water.
When should I fertilize my Common hollyhock?
The best time to fertilize a Common hollyhock is in late winter to early spring when it is transitioning from dormancy to active growth. Fertilizing at this time promotes healthy growth for the upcoming season. Although early spring is generally the most beneficial, fertilizing in the fall is also acceptable. Avoid fertilizing in summer and winter as it is not recommended for the plant's well-being.
What are the symptoms of insufficient or excessive sunlight in Common Hollyhock?
Common Hollyhock shows different symptoms depending on the light conditions. Insufficient sunlight can lead to small new leaves, leggy or sparse growth, faster leaf drop, slower or no growth, lighter-colored new leaves, and risks of chlorosis. Excessive sunlight, on the other hand, may cause sunscald, leaf curling, wilting, leaf scorching, indicating damage from overexposure. These symptoms highlight the plant's need for the right amount of sunlight to maintain health and vigor.
What are the symptoms and solutions for common hollyhock exposed to low temperatures?
When exposed to low temperatures, common hollyhock demonstrates remarkable cold tolerance, thriving best when temperatures are above 20°C and should ideally be kept above 0°C during winter. If temperatures fall below -40°C, the plant may not show immediate changes during the cold season, but a decrease in sprouting or a complete lack of sprouting can occur in spring. The solution for this issue involves removing any parts of the plant that have failed to sprout in spring, which helps encourage new growth.
