How To Care For A Mexican Petunia

Mexican petunia, or Ruellia brittoniana, is easy to grow under most conditions. These plants will produce blooms in almost any type of soil, and are resistant to drought and wet conditions as well. Mexican petunias are perennial shrubs, which can grow as tall as 3 feet. There are also some dwarf species available, which will grow only to less than 1 foot. With minimal care and supervision, these plants produce attractive, tubular flowers. The flowers are generally bluish or purple in color, and similar in appearance to common petunias. However, the two plants are not related. In cold climates, Mexican petunias can be grown as annuals, which must be replanted every year. These plants are very attractive to butterflies, which makes them popular choices in many backyards.

TIP: Our expert gardening adviser, Kathy Bosin adds, "Gardeners seem to either love Ruellia, or dislike it's invasive nature. In some areas of the country, a sterile version of Ruellia which will not re-seed can be found at nurseries and garden centers.

Soil and Planting Site

Mexican petunias are also known as desert petunias, and more sunlight means more flowers. Choose a sunny spot in your backyard. Though Mexican petunias are highly adaptable to most soil types, they grow better in fertile soil that is well drained and capable of retaining the required amounts of moisture. Amend the planting spot with some mature compost, and remove all weeds 4 to 5 weeks before planting. Soil drainage can be improved by incorporating some sand and thoroughly mixing it in with the soil. You can easily propagate these plants by cuttings, seeds, or by divisions. The roots are very easily formed in such a planting spot, in the right temperature and climate. The best time to plant Mexican petunias is early spring, when there is no chance of frost. Once established, the plant will bloom profusely throughout the warmer periods of the year.

Watering

Once established, Mexican petunias are very hardy, and can survive for long spells without water. However, young plants need regular watering. You can also grow these plants indoors in pots, provided they have a sunny location. Indoor plants must be watered regularly as well during hot weather. Keep away from heat vents and electrical equipment. In the winter, indoor Mexican petunias must only be watered when the soil shows signs of drying. These plants are highly resistant to most pests and diseases.

Maintenance

In warmer climates, Mexican petunias can grow rapidly and propagate themselves by means of seeds. In some areas, this plant is considered an invasive species, because they can spread very fast, taking over the backyard, if not controlled. If you feel that these pretty plants are taking over your backyard, you can easily pull out the required number of stems. These shrubs also need regular pruning to maintain their shape and appearance. The stems are woody and tough.

If you want more of these beautiful flowers in your backyard, cutting stems halfway after flowering will result in the growth of several more stems and flowers. In colder climates, the foliage will be damaged by frost, in which case the damaged parts must be removed and disposed of promptly, to avoid infection.