The beautiful, soft-petaled, easy-to-grow petunia is a flower straight from our childhood.
Sunlight: Full sun to partial shade
Maturity: 55-75 days from seed to flower
Height: 10 to 18 inches
Spacing: 8 to 18 inches apart in all directions
Flower gardeners are growing petunias for their dazzling colors and prolific blooms that continue from early spring until frost. Available in hundreds of varieties, petunias are one of the most popular flowering annuals and are well suited for use in borders, baskets and containers.
Native to South America, the first petunia specimen (Petunia multiflora) was discovered at the mouth of the Rio de la Plata and was white in color. The original plants were hardy, had trailing 2-3 inch stems and incredible scents. These scents have been lost in many of the modern-day hybrid varieties. Fortunately, many of the old fashioned, heirloom varieties are still available to fill the air with their amazing fragrance. Plants grow 10-18 inches tall. Self-seeding annual.
Petunias require full sunlight to thrive, but will tolerate some shade. The more shade they receive, the fewer flowers they will produce. Soil should be average to rich and well-drained. Prior to planting work a shovelful or two of organic matter, such as compost or well-aged manure, into the soil (watch Flower Gardening from the Ground Up – video). This helps condition the soil, which improves drainage and will also increase the ability of lighter soils to hold water and nutrients.
How to Plant:
Petunias may be grown from seeds or seedlings. If growing from seeds, sow indoors on the surface of the soil 8-10 weeks prior to last frost (see Starting Annual Flowers Indoors). Pinch off the top inch before planting to encourage good branching and transplant when the danger of frost has past. For good ground cover, space plants 12-18 inches apart. Fertilize monthly with a liquid organic fertilizer to promote healthy growth and remove spent flowers on a regular basis to extend the blooming period.
Insects and Disease:
Petunias do not have many insect or disease pests. Watch for aphids, flea beetles and slugs, which can occasionally attack plants and use natural pest controls, when needed. Avoid wetting the foliage when watering to help prevent common plant diseases, many of which are characterized by wilting, spots and rotted tissue.
Seed Saving Instructions:
Petunias are self-seeding. You can save the seed if you’re interested, but the flowers won’t always come true to type. They usually revert to a mix of small white, lavender and rose flowers.