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Hollyhock (Alcea rosea)
- These biennial plants often behave as perennials in the garden with new plants growing from seed each year
- Flowers come in a wide range of colors, including a purple that looks almost black!
- Hollyhock rust is a serious disease issue and Japanese beetle is a serious pest for hollyhock in Iowa
Common Name(s): hollyhock
Scientific Name: Alcea rosea
Size: 6 — 8’ tall; 1 — 2’ wide
Hardiness: Zones 2 — 10
Leaves: large heart-shaped (3, 5, or 7 lobes), rough lower leaves which become progressively smaller toward the top of the spire.
Leaf Color: green
Flowers: plants produce huge (4-5" diameter), outward-facing, single flowers in a wide variety of colors including reds, pinks, whites, and light yellows from June to August.
Fruit: not significant
Habit: towering spikes or spires which typically reach a height of 5-8' tall and usually do not require staking.
Stem: usually hairy.
Nativity: Not native to United States
Insects & Disease Issues: foliage is susceptible to rust, leaf spot, and anthracnose, spider mites and Japanese beetle can also be problems.
Culture and Uses:
This biennial is a old-fashioned cottage garden favorite in the back of the garden border. As beinnials, the first year of growth is a low growing rosette of leaves. Plants produce a flowering stalk the following year. While individual plants are short-lived, plants grow easily from seed and will establish long-lived colonies and behave much like perennials with some plants in flower and others just a rosette of leaves. Grow in full sun in moist well-drained soil. Select named cultivars as they are often more resistant (though not entirely) to the common rust disease that makes plants nearly leafless by late August. Plants abhor wet winter soils and when grown in too much shade will flop over.…..actually when grown in full sun they are often prone to that—good drainage and full sun will help. Plants may need staking to stay upright. Grow in areas that are not prone to winds as the tall stalks can eaily be toppled without support or protection. Double and single flowers can be grown and shorter varieties will not need to have nearly as much staking.
Notable Cultivars & Related Species:
‘Nigra’ - dark purple, nearly black flowers
Queeny Series—semi-double flowers, several colors, seed propagated
Charters Series—double flowers, several colors
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