Different types of hibiscus plants can be grown in most parts of the United States, the exception being the coldest areas. They all have large, fragrant, delicate-looking flowers that can come in a large variety of colors and a wide range of sizes--small bushes, large bushes and small trees.
The tropical hibiscus is from Asia and the South Pacific. It comes in almost every color, but never true blue or black. The flowers can be as small as 2 inches in diameter or as large as 12 inches in diameter. Some bushes will only reach about 1 foot in height, while others can grow as tall as 15 feet. The blooms can be single or double, and most varieties only last for one day. They need moist and well-drained soil and partial shade. They can be planted outdoors in zones 9 and 10, the two hottest zones in the continental United States, but should be covered if a freeze is expected. Different varieties of tropical hibiscus can live anywhere from 5 to 50 years.
Hardy hibiscus can be found growing from Massachusetts west to Wisconsin and Missouri and in the southeastern part of the United States. Hardy hibiscus flowers can be around 10 inches in diameter and can grow from 4 to 6 feet in height. The colors can be white, pink or deep red. The leaves can be either green or bronze. Hardy hibiscus are classified as herbaceous perennials, which means that they will die back to the ground in the winter, but grow new shoots from the same plants the next spring. They need to be in full sun every day to get the most blooms. The hardy hibiscus can take any kind of soil from dry to soaking wet.
Rose of Sharon
Rose of Sharon--Hibiscus syriacus--grows naturally as a medium-sized ornamental shrub, but can be trained to grow as a small tree. It will grow to a height of about 8 feet and a width of about 4 feet. The plant can take full sun or partial shade and does best in moist, organic, well-drained soil, but can adapt to other soil types. It is a good choice for an urban environment because of its ability to adapt to pollution. The leaves are 3 inches long and green, turning to chartreuse in the fall. The flowers are about 4 inches wide in white, red, purple, mauve, violet or blue; they can also be bicolored, with petals one color and the throat a different one. They will bloom from July all the way though to the end of September, and most varieties will close up at night. Rose of Sharon is hardy in zones 5 to 8.