Hollyhocks, or Alcea rosea, have been grown in gardens for hundreds of years. They make many of us think of the gardens our parents or grandparents had. Despite being ‘old-fashioned,’ hollyhocks have had a bit of a resurgence in recent years. Their tall, stately flowers are an impressive sight in the garden.
Hollyhocks are native to Asia and are part of the mallow family, along with cotton, okra, and hibiscus. Plants usually grow 3-6 feet tall, but some cultivars can approach 9 feet. Because they are tall, they are often used as background plants in flower beds or along walls or fences.
Flowers will begin opening near the base and proceed up the stem. Each flower will stay open for three to four days, and the plant will bloom for about four weeks, from late spring to early summer. Blooms usually come in red, but they can also be pink, purple, yellow, white, or “black,” which is usually a dark purple.
Hollyhocks are biennials, growing as a rosette of leaves the first year and producing flowers the second. Occasionally, they are short-lived perennials. Even though they don’t last long, they easily reproduce by self-seeding, so they can stay in the garden (if plants are allowed to make seed).
Hollyhocks are easy to grow. They grow best in a location with full sun and well-drained soil. Given their tall size and tendency to flop, they also benefit from having protection from the wind. If you plant them somewhere that will get windy, you might need to stake them to keep them from getting damaged. You can also pinch the main stems early in the season to make plants bushier and shorter, so they won’t need to be staked as often.
One of the most commonly encountered insect pests on hollyhocks is the hollyhock weevil (Rhopalapion longirostre). They are small, gray beetles with orange legs. Like all weevils, they have a long “snout” (which has the mouth at the end of it). The adults will feed on buds, tender stems, and emerging leaves. When plants start to make flower buds, the adults will start to eat them, and the females will lay their eggs in the buds.
When it grows up, the cream-colored larva will eat the seeds and come out of the seed pod. This feeding can lower the number of seeds that are made, which can make it harder for hollyhocks to reproduce by self-seeding. Removing and destroying the infested seed pods can help manage weevil populations. Spraying plants with an appropriate pesticide can help manage beetle populations as well. Make sure to read and follow all label directions.
Hollyhocks are also a favorite plant of Japanese beetles. Adults will feed on leaves, causing the leaves to be skeletonized. Japanese beetles can be hand-picked from plants or sprayed with an insecticide.
Hollyhocks are susceptible to a few diseases, the most common being hollyhock rust (Puccinia malvacearum). Plants that are infected will get orange or yellow spots on the tops of their leaves, which usually start on the lower leaves. Eventually, brown to dark-red bumps will form on the undersides of the leaves. Minor infections won’t harm the plant. However, severe infections can cause leaves to shrivel and die.
Several plants in the mallow family can get hollyhock rust. One of these is common mallow (Malva neglecta), a common weed that can spread the disease. Therefore, removing it if you have any in your landscape is important to prevent the spread of rust. If hollyhock plants are infected with rust, there are several things you can do:
Good Growing Fact of the Week: Hollyhocks are also called outhouse flowers. They were often put around outhouses to hide them and keep people from having to ask for directions, which would be embarrassing.
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GET TO KNOW THE AUTHOR: Ken Johnson has been a Horticulture Educator for the University of Illinois Extension since 2013 in Calhoun, Cass, Greene, Morgan, and Scott counties. Ken provides horticulture programming with an emphasis on fruit and vegetable production, pest management, and beneficial insects. Through his programming, he aims to increase backyard food production and foster a greater appreciation of insects.
With their tall spires of colorful blooms, hollyhocks are a beloved old-fashioned flower. But what do the leaves of a hollyhock plant look like? Here are the key features that make them stand out:
Leaf Shape
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Hollyhock leaves have a rounded almost heart-shaped form. They are broadly lobed with edges that are lightly ruffled or wavy.
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The leaves are palmately veined, meaning the veins radiate out from a central point like fingers on a hand There are typically 5-7 main veins
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Leaves emerge from the central stem in an alternating pattern up the tall flower stalk. They have long leafstalks attaching them to the main stem.
Leaf Size
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Mature hollyhock leaves grow quite large, reaching sizes of 4-12 inches across. However, newly emerging leaves start out much smaller.
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Lower leaves on the plant tend to be the biggest. Leaves get progressively smaller as they ascend the flower spike.
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The wide, rounded shape gives the leaves a very full, broad look. Especially the large lower leaves.
Leaf Surface
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Hollyhock leaves have a slightly rough, sandpapery texture. Very young leaves may be smooth at first before toughening up.
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The upper surface is dull green in color, while the undersides are a paler green. Tiny hairs can be found on both sides.
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Older or lower leaves often develop a leathery appearance and become wrinkled looking.
Identifying Damage
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Hollyhock leaves are prone to insect damage. Look for chewed holes, skeletonization and yellowing spots.
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Lower leaves may turn yellow or brown and drop off as the season progresses. This is normal.
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Powdery white spots on leaves point to powdery mildew fungus. Rust fungus causes reddish or orange spots.
How Hollyhocks Grow
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Hollyhocks are biennials or short-lived perennials, living for just 2-4 years in most cases.
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They form a tall central stem that can reach heights of 4-9 feet tall at maturity.
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The lower portion of the stem is leafy. The upper portion becomes naked and bears flowers.
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Flower color ranges from white to pink, red, purple, yellow and more. Both single and double blooms exist.
Where to Find Hollyhocks Growing
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Look for hollyhocks in cottage gardens, perennial flower beds, and informal garden settings. They add height and vertical drama.
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Often found growing against walls, fences or barns. The support helps keep the tall flower stalks upright.
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Sometimes escape gardens and naturalize along rural roadsides. Can be found growing wild in fields.
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Available as started plants from nurseries in spring. Can also grow from seed sown directly in the garden.
With their distinctly shaped, boldly lobed foliage and tall stature, hollyhocks create a unique presence in the garden. Their leaves are quite distinctive once you learn to recognize them. Pay attention to the leaf shape, veining, surface texture and large size to properly identify hollyhocks.
HOW to PLANT and GROW HOLLYHOCKS plus TIPS for growing hollyhocks in HOT CLIMATES
What color are Hollyhock flowers?
Flowers growing on hollyhock plants can be shades of pink, red, yellow, purple, and white. There is also a spectacular hollyhock plant with black flowers. In most varieties, hollyhock flowers grow along the length of the upright stems. On some types, only the top 24” (60 cm) of the stalk blooms.
What do hollyhock leaves look like?
Hollyhock leaves are large, rounded leaves in a palmate or scalloped shape with five to seven lobes. Leaves on hollyhock plants measure 2” to 3” (5 – 7.5 cm) across. An identifying feature of hollyhocks is the large round leathery leaves growing on long stems (petioles).
Is HollyHock a perennial?
Hollyhock ( alcea rosea) is a species of flowering garden plants with colorful white, purple, pink, red, and yellow cup-shaped flowers growing on tall spikes. Hollyhock flowers have a long blooming season, and their tall growth makes them useful landscaping plants. Easy to grow from seed, hollyhocks grow as short-lived perennials or biennials.
How tall do hollyhocks grow?
Due to their tall height, hollyhocks are ideal for growing at the back of flower beds, along fences and walls, or staked to prevent the long stalks from snapping in the wind. Hollyhock flowers are identified by cup-shaped vibrant blooms that are single or double-flowered varieties. The beautiful flowers grow 3” to 4” (7.5 – 10 cm) across.