“I am the rose of Sharon, and the lily of the valleys. As the lily among thorns, so is my love among the daughters. As the apple tree among the trees of the wood, so is my beloved among the sons. I sat down under his shadow with great delight, and his fruit was sweet to my taste.” The Song of Songs 2:1-3
The rose of Sharon is a common name used for several unrelated plants. In our area, it is commonly identified as althea, properly named Hibiscus syriacus.
Althea is definitely not the original rose of Sharon, since it is native to
Nevertheless, our althea is worthy of use in local gardens because it produces abundant blooms and grows remarkably well here.
An early introduction to American gardens, it was probably carried over by Dutch or English colonials.
Although naturally a multi-stemmed shrub, this plant can be trained through pruning to a single trunked “tree.” It can also be trained for espalier and hedges.
Other than regular pruning to prevent weediness, this plant requires little attention. Watering and fertilizer should be kept to a minimum. Althea prefers full to partial sun in our area, is heat and salt-tolerant and likes dry feet.
While it is deciduous, it remains green most of the year here and can bloom year round.
It can be propagated by cuttings but be aware that it will grow from seed and can produce numerous volunteer shoots. Unfortunately, these are generally hybrids lacking the characteristics of the parent plant including flower color.
The commonest criticism of althea is that the color of the flowers can be muddy, so be sure to choose your plant when it is in bloom. Flowers come in shades of red, pink, white and purple.
The beautiful double althea pictured here is proof positive that cultivars with clear beautiful color are available.
Althea can reach 10 feet in height. Dwarf varieties, which only grow to six feet tall, are available.
Although they are strong growers, especially older plants may experience a variety of problems, most of which can be solved by pruning or adjusting water and fertilizer.
The commonest pest of althea is aphids, which accumulate at the tips of stems, causing new growth to be misshapen. Aphids may cover the leaves with sticky honeydew, which turns black when infected by sooty mildew. Aphids can be dislodged with high-pressure water sprays or pruned off with infested foliage. Be sure to remove pruned greenery from the garden. Over-fertilizing increases aphid infestations.
Japanese beetles are particularly fond of the flowers.
Leaf spot is a symptom of bacterial infection. Pick off and destroy the infected leaves. Canker can cause bright, reddish-orange fruiting bodies to appear on the bark. Prune out infected branches. Flowers are subject to fungus.
After pruning a diseased plant, always clean tools in bleach before using on another plant.
Bud drop can be caused by too much or too little water or over fertilization.
The flowers of althea, both dried and fresh, were traditionally used as a winter tea and contain abundant antioxidants.
“Urban Forager” a website produced by the
Unripe seedpods are also edible.
Flower buds contain mucilage, a gooey medicinal compound made of polysaccharides. This substance has been used to treat burns, wounds, gastric ulcers and internal and external inflammation and irritation, such as sore throats or urinary tract infections.
The bark is being studied for cancer inhibiting properties. The Chinese use the root bark as an antifungal remedy.