What Is a Mexican Petunia?

The Mexican petunia is a shrub-like flowering plant that as a perennial can continue to grow from one year to another. It can usually survive in various environments, including extremely wet locations and in places with persistent drought. Planting a Mexican petunia can take some work to get the shrub to become established. Invasive types, however, can grow rapidly, produce many seeds, and re-grow from roots when the plant is killed by frost or cut away. They often grow in wooded areas and prairies, in pastures, and near rivers.

A stalk-like form is typical of the Mexican petunia, which can grow up to 3 feet (about 0.9 meters) high. Dwarf species, however, often stand less than 1 foot (about 0.3 meters) high when fully grown. The plants can have purple or bluish flowers that are typically tube or trumpet shaped, while dark green leaves may be anywhere from 6 to 12 inches (about 15.2 to 30.5 centimeters) long. When grown in climates where it is usually cold for much of the year, these petunias can be planted annually. In warm climates, they generally grow quickly and can survive brief periods of frost.

Backyard locations should typically be selected carefully before growing petunias. The most suitable spot is usually one that gets the most sun, while well-drained, fertile soil is generally best for growing. Sand often helps to drain the soil when it is mixed in. A Mexican petunia can be planted by spreading seeds or using cuttings from other plants. It is generally able to become better established if planting is done in the spring.

While most Mexican petunia plants can go for a long time without water, young ones need to be watered regularly. They can also grow indoors in a flower pot. Outside, they can easily proliferate in a backyard if not pruned often and, like in the wild, are resistant to most plant-borne diseases as well as pests. Gardeners typically have the option to buy the plant, like many others, through retailers in addition to on the Internet.

In locations where Mexican petunia plants have invaded, pulling them out by hand is often the only way to get rid of them. Some areas may need to be mowed and tilled, but seeds can still get into the soil and grow into new plants. As of 2007, no biological agents had been found that could kill the shrub, while glyphosate may work if used on it at the right time.