|Alcea subsp. var.||Hollyhock|
The hollyhocks comprise about 60 species of flowering plants in the genus Alcea in the mallow family Malvaceae, native to southwest and central Asia. They are biennial or short-lived perennial plants growing to 1-3 m tall, with broad, rounded, palmately lobed leaves and numerous flowers, pink or yellow in the wild species, on the erect central stem.
Hollyhocks are popular garden ornamental plants, with numerous cultivars selected, particularly from A. rosea. The flowers have been selected for variations in colour, with dark purple, red and white-flowered plants available in addition to the colours found in wild plants.
Hollyhocks are very drought resistant, and do well in full sun locations that might be too hot or dry for other plants. They produce large, flat coin-shaped seeds (1/2" diameter) that seem to grow easily wherever they drop. While an individual plant might only live a handful of years, by that time chances are good it will leave plenty of descendants.
|Standard Cyclopedia of Horticulture|
Hollyhock (Althaea rosea, which see). Figs. 1844, 1845. The hollyhock is one of the very oldest of cultivated flowers and is today an inhabitant of most gardens, and is known by its common name not only to all cultivators of plants but even to school-children. Its showy blossoms in July after the larger number of plants have ceased flowering has much helped to make it known to all, while its history, its place in poetry and folk-lore, and its associations in the past drama of the world have been forgotten or vaguely remembered. Its beauty causes its cultivation today.
The hollyhock is a native of China, botanically described as a biennial and evidently a cultivated plant in China when first brought to the attention of European cultivators, since it is said to have been "of many colors and forms." Very probably its colors in a wild state, as now often seen in mixed retrograde seedlings, were rose-pink tending to red and white. The real reds and the present deep maroon shades would naturally be obtained rather easily by selection. The yellow color is, in the opinion of some, a much later acquired one, and the least liable to come true from seed.
The doubleness of the flower has undoubtedly been an acquired character under cultivation. The hollyhock has been propagated almost entirely from selected seed for so many years that both in color and doubleness it comes true from seed which has not been cross- fertilized with other colors or forms.
The bees delight in the plentiful pollen of the holly hock so that in a mixed group of plants the seed will be indiscriminately crossed, and naturally a few poor single-flowered plants may affect the seed from a whole group. The color of the flower is, however, much influenced by the seed-bearing parent. The pollen on the hollyhock is so plentiful that the bee soon gets a load and goes home, in many cases not having visited more than one plant. For this reason a short distance between groups, especially if separated by some barrier, very much prevents cross-fertilization. Purchased seed comes about 75 per cent true to color and possibly 40 per cent fairly double.
The hollyhock, while called in botanical history a biennial, is at least a short-lived perennial. Its heavy type of root with very short stolons or rather side crown-buds at the head of the root-system would naturally lead to its description as a biennial. It belongs, because of its root-system, to a horticultural class of plants, which, while truly perennial under proper conditions become biennial or even annual under other circumstances. Other plants having very similar root-formations are the dandelion, digitalis, aquilegia, platycodon and delphinium. These are more or less short-lived perennials since their permanency depends on the preservation of an easily destroyed crown-bud or rather the head of the root-system. Heaving of the plant by frost exposes the main root- stem below the side buds and causes the plant to die after flowering. In like manner the removal of soil from about the plants, as by rains, shortens the life by exposing the root below its natural level with the soil. The seed of the hollyhock, as well as the other genera mentioned with this root-system, germinate very quickly —five to ten days.
Hollyhock seeds sown in the greenhouse or frame during March or earlier and given plenty of root-room will flower the first year from seed although somewhat later than established plants. Plants grown as above in pots are likely to show less perennial character of the root and are more liable to disease. The seed should be sown outdoors during June or July in soil with sufficient clay and surface soil-water to cause the seedlings to form a system of strong side tap-roots, rather than one or two main roots as will occur in too sandy or dry soil, or on the other hand too many fibrous surface- roots as when grown in pots or in a too-wet soil.
Plants from outdoor spring- or early summer-sown seed should be moved to their permanent positions early the following spring, care being taken to dig the plant with all the main roots, and in planting to place these roots in a natural position, i.e., pointing downward. The crown of the plant should be a little below the surface of the ground (this is important). Fall planting, with the heaving by frost, especially of tap-rooted plants, means replanting in the spring to the proper depth or the usual loss of the plant after one year's bloom.
Hollyhocks may be propagated in the spring by placing a plant in sand so as to cover the crown of the root which will cause a number of suckers to be sent up about the crown, which may be removed and rooted.
The hollyhock rust (Puccinia malvaceaerum) bothers very little m deeply dug and drained beds with plants grown outdoors and planted with the tap-roots properly placed and the crowns in the proper place in reference to the soil-surface. An appreciation of the deep-rooting, drainage-liking habit and qualifications of the plant will do more to combat this disease than any amount of bordeaux mixture. In the United States Experiment Station Record, Vol. XXXI, No. 3, note is made from an article in a French publication (Compt. Rend. Acad. Sci. 158, No. 6) which declares the hollyhock rust to have been successfully combated during a three- year trial by supplying as water to the roots a 3 per cent solution of copper sulfate.
In landscape work, the hollyhock best belongs to the herbaceous perennial groupings, but it can be well used alone in groups adjoining shrubbery, or in many places in place of shrubbery. It can seldom be used to advantage in mixture with woody plants, since the hollyhock needs light on its lower basal leaves. Further, the foliage of the hollyhock neither resembles nor contrasts well with that of the larger number of shrubs, although there are exceptions, for example, hydrangeas of the arborescens type and hollyhocks form a pleasing mixture-.
Describe the plant here...
Plants flower from from mid-summer to autumn so a little care in cultivation is well worthwhile: they are best staked,as reaching 1.5 to 2 metres high in a season they have rather poor wind resistance. Are very prone to disfiguring rust disease - evident as bright orange pustules on leaves and stems - which spoil the appearance; fortnightly fungicide sprays will keep rust at bay; most effectively by using different products in rotation.
Pests and diseases
About 60 species, including:
- Alcea biennis
- Alcea ficifolia - Antwerp Hollyhock
- Alcea heldreichii
- Alcea lavateriflora
- Alcea pallida
- Alcea rosea - Common Hollyhock
- Alcea rugosa
- Alcea setosa - Bristly Hollyhock
- Alcea striata
- Alcea sulphurea
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963