KC Gardens

Plant of the Week: Rose of Sharon

Rose of Sharon
Rose of Sharon Submitted photo

Driving around older neighborhoods in small town Kansas on a hot summer day, you will start to notice a common plant in the landscape. This plant goes by several names, depending on your age and place of origin. To some it is known as old-fashioned Althaea, while to most people it is known as Rose of Sharon. The plant was grown and documented by Thomas Jefferson in his gardens.

Generations have enjoyed the brightly colored summer flowers of this hardy shrub. Botanically speaking, the plant is Hibiscus syriacus. This member of the Mallow family can reach as tall as 8 feet with a spread of about 4 feet. It tends to grow in a more upright vase-shape habit with a medium to fast grow rate. It is now common to see this timeless shrub pruned into a tree form and used as an accent for small spaces.

Culture of this plant is fairly easy, as it will take full sun to partial shade. Heavy shading will reduce flowering. This shrub prefers moist, well-drained soils supplemented with organic matter, but is very adaptable to various pH levels, drought and hard pruning. It has only minor pest problems and rarely, if ever, would need a pesticide application or fertilization, making it an environmentally friendly plant.

The most striking feature of Rose of Sharon is its summer flowering habit. Blooms start appearing in July and can last well into September, adding much needed color to the landscape. Flower color ranges from solid colors of white, red, purple, mauve, violet blue, or bicolored with a different colored throat, depending upon cultivar. Flowers can reach 4 inches or more across and usually last one day, closing up at night.

One potential drawback to this plant is the seed pods. Older varieties may reseed themselves in the garden, becoming a nuisance. Newer varieties tend to be virtually fruitless, reducing this reseeding problem and making the plants more desirable. With care, young seedlings can easily be removed. Avoid seedlings from friends because these will also reseed in your garden.

Rose of Sharon is an easy shrub to incorporate in the landscape as it has many uses. The tree form can be used as a specimen while the shrub can grace the foundation of the home, be incorporated into a shrub border, added to a perennial garden for structure or planted in a hedge to create an informal screen.

There are many wonderful newer varieties on the market. Some of the most notables are named for Greek goddesses, such as ‘Aphrodite,’ a single flower pink-mauve with a dark magenta center or eye, ‘Diana,’ a heavy single white flowering type, and ‘Minerva’ with lavender single flowers possessing a red eye. Food flavored names are also popular with ‘Lavender Chiffon’ or ‘Blueberry Smoothie’ which has large lavender/blue flower petals.

Fall is a good time to add a Rose of Sharon to the garden, as many will still be sporting blossoms. This lets you see what array of colors are available and which will suit your garden taste. Even though these plants have graced gardens for years, they are still proving why they should remain a favorite.