Alcea rosea is a flowering plant that thrives in areas with low rainfall. It grows to be about 2 feet tall and has flowers that are pink, red, or white. The flowers have a mild scent that is reminiscent of citrus. Alcea rosea is often used as an ornamental plant due to its attractive appearance and blooming season. It can be used in gardens or containers because it doesn’t require much space to look pretty.
I. Appearance and Characteristics
Alcea rosea, the common hollyhock, is an ornamental dicot flowering plant in the family Malvaceae. It was imported into Europe from southwestern China during, or possibly before, the 15th century. William Turner, a herbalist of the time, gave it the name “holyoke” from which the English name derives.
Growing up to 8 feet tall, this plant usually does not require staking, producing large flowers around 5 inches in diameter. Its leaves are large and heart-shaped. The flowers attract hummingbirds and butterflies.
Alcea rosea is variously described as a biennial (having a two-year life cycle), as an annual, or as a short-lived perennial. It frequently self-sows, which may create a perception that the plants are perennial. The plant may flower during its first year when sown early. It will grow in a wide range of soils, and can easily reach a height of 8 ft (2.4 m).
The flowers are in a range of colours from white to dark red, including pink, yellow and orange. Different colours prefer different soils. The darker red variety seems to favour sandy soils, while the lighter colour seems to favour clay soils. The plants are easily grown from seed, and readily self-seed. However, tender plants, whether young from seed or from old stock, may be wiped out by slugs and snails. The foliage is subject to attack from rust (Puccinia malvacearum), which may be treated with fungicides. Commercial growers have reported that some closely related species (Alcea rugosa and Alcea ficifolia) are resistant to this fungus.
II. How to Grow and Care
Sunlight
While full sun is best, hollyhocks will also grow in partial sun or light shade. Lots of sunlight equals less spindly plants and a lower likelihood of disease. Make sure to seek a sunny area that also offers refuge from the wind—for example, a fence or arbor to lean against.
Temperature and Humidity
Daytime temperatures of 70℉ or warmer and nighttime temperatures of at least 60 to 65℉ are optimal for growing. In very hot, humid conditions, hollyhock is more likely to develop rust, and the disease tends to worsen as the summer goes by. These upright flowers also look their best early in the summer, before they’ve been worn out by the elements.
Soil and Water
Hollyhock can handle lots of different soil types. Ideally, seek a spot with well-drained soil, though hollyhock will also take root in clay. pH isn’t a major consideration, as these towering flowers will grow in acidic, neutral, or alkaline soil. Make sure to avoid wet winter soil.
When you first plant a hollyhock, keep it well-watered to allow the roots to take hold, then continue to water it regularly throughout the growing season. Using a soaker hose, direct the water at the base of the plant to avoid splashing the leaves; wet leaves can lead to rust, the most common plant disease in hollyhocks.
Fertilizing
When you first plant hollyhock, adding a slow-release fertilizer to the soil can help it thrive. Once the plant is mature, you shouldn’t need to continue fertilizing (although it’s okay to do so).
Planting Instructions
The easiest way to add these towering beauties to your garden is buying potted hollyhocks. You can place them as close as 12 to 18 inches apart, although you might consider giving them more room, since hollyhocks self-seed. Spacing them 3 to 4 feet apart will allow for this natural spread. In the spring, wait to plant until after the threat of frost has passed, and in the fall, plant your hollyhocks before the ground is frozen.
Be patient when planting, especially if you’re growing hollyhock from seeds. Many of the most common varieties are biennials. This means they spend their first year growing foliage and storing nutrients for the following year. In the second year, hollyhocks use this stored energy to put on a spectacular floral show and create as many seeds as possible. Hollyhocks die at the end of their blooming season, but fortunately, they shed lots of seeds to start the whole process again.
Pruning
Throughout the growing season, remove any dead or dying foliage, especially any leaves infected with rust. Once the flowers are past their prime, you can cut the hollyhock spikes to the ground.
Propagation
If you plan on growing hollyhocks from seed, know that you typically won’t see blossoms until the second year. Although these plants require patience, they are easy to grow by direct-sowing the seeds. You can scatter the seeds in the spring all the way through the summer, about 2 months before the first fall frost. Don’t cover them with soil—you want sunlight to reach the seeds and encourage germination.
If you want to start seeds indoors before spring, begin growing them about 6 to 8 weeks before the final frost. Make sure you move the seedlings outside while they’re still young to avoid damaging the taproot.
Although transplanting hollyhock is difficult due to the plant’s delicate taproot, it can be done in early spring. Start by cutting back the stems and foliage, leaving about 6 inches above the ground. Dig on all sides of the plant with a spading fork; pry the plant out of the ground, then shake off the excess dirt. Cut the plant into several sections, and divide the taproot with a knife, peeling it almost like a potato. Each section should have a piece of root with at least a couple of “eyes.” Plant the sections as quickly as possible.
Pests and Diseases
- Common Pests
Pests aren’t considered a major concern for hollyhocks. However, young hollyhocks can attract slugs and caterpillars. Spider mites and Japanese beetles may also be a problem.
- Hollyhock Rust
If you’ve ever admired hollyhocks up close, you may have noticed some not-so-pretty foliage at the bottom. Unfortunately, these plants are prone to a type of rust that’s specific to members of the hollyhock family. The first sign of hollyhock rust is yellow spots on the lower leaves; as the disease progresses, brown- or rust-colored bumps will often appear on the underside of leaves.
Hollyhocks grown in high humidity or in places with poor air circulation are especially vulnerable to rust. Although its effects are unsightly, this disease usually doesn’t kill the plant.
Keep an eye out for early symptoms of rust. Spores from fungus are spread easily by water and wind, so splashes from rain or a hose can spread the fungus to plants nearby. Keep foliage dry and water at the base of the plant to avoid this. If you notice yellow-spotted leaves, remove the affected foliage, then burn or seal them in a bag for disposal.
- Anthracnose
This highly damaging fungal disease causes leaf spots and black splotches on the plant’s petioles (the leafstalks) and stems. It may also attack the roots and the section of the stem closest to the ground. Hot, humid conditions predispose plants to anthracnose infection, and watering and rain can spread the fungal spores. If you spot diseased foliage, remove and burn it, then apply a fungicide to the plant as needed. Proper spacing of plants will reduce the risk of this disease.
- Leaf Spot
Also caused by a fungus, leaf spot is characterized by small, gray spots dotting the leaves. As the diseased areas die, holes may appear on the foliage. Remove any infected leaves, burn them, and apply a fungicide as needed.
Maintenance
The care requirements may differ for the different species of Alcea rosea. Most of them are adaptable and cold-hardy plants. When growing these plants, make sure to choose a sheltered area protected from wind to avoid these tall plants from drooping. Space the individual plants, about 18 to 24 inches apart to allow good air circulation.
III. Uses and Benefits
- Ornamental uses
Common hollyhock is good for planting in rock gardens and flowerbeds. It is prized for its ornamental blooms and is a staple in flower beds and borders in cottage gardens. It is often considered a good filler for summer bulb beds, and grows well with pansies and campanulas.
- Medicinal uses
In herbal medicine, hollyhock is believed to be an emollient and laxative. It is used to control inflammation, to stop bedwetting and as a mouthwash in cases of bleeding gums.
Alcea rosea is a flowering plant that has been used for centuries to help treat skin conditions such as eczema and psoriasis.
In addition to being used to treat acne, it has been demonstrated to aid in hair growth.
To cure wounds, burns, and cuts, this plant’s leaves can be brewed into tea or made into a tincture.
Alcea rosea may also be used for its astringent properties, which may aid in healing wounds and preventing scarring.
The stems of this plant are used as a herbal tea or decoction to treat internal inflammation.
Find Where to Buy the Best Hollyhock (Alcea rosea)
[content-egg-block template=offers_logo_shipping cols_order=3,2,1,5,4 hide=badge visible=number border_color=info limit=8]