Petunias have been popular in gardens for decades. For many years, we have had a rainbow of colors of grandiflora petunias which are known for their large flowers and multiflora petunias which are known for their greater number of smaller flowers. But as all Texas gardeners know, these petunias don't hold up to the heat and humidity of our summers. Several years ago, the ‘Laura Bush’ petunia (a Texas Superstar® plant) was introduced by Greg Grant, Texas plantsman extraordinaire, as a new type of petunia that could take our torrid conditions. It was representative of a new class of petunias referred to as the trailing petunia. After several years of testing, two more trailing petunias are being brought into the Texas Superstar® fold. The new designees are ‘Tidal Wave™ Silver’ and ‘Tidal Wave™ Cherry’, both introduced by PanAmerican Seed™.
Tidal Wave™ Cherry is a bright cherry red that can be seen from a quarter mile away at 70 miles per hour. It is a great plant to use in hot color schemes where bright colors dominate. Or it can be toned down with softer flower or foliage colors. Tidal Wave™ Silver, on the other hand is white with a lavender blush (or can be describe as silvery white) that mixes well with purple foliage in cool color schemes.
Both Tidal Wave™ Cherry and Silver have been tested in locations across the state and been found to thrive in summer conditions. They need at least 6 hours of sun each day to flower well. In the heavier soils of Dallas and San Antonio, chlorosis is not a problem as it can be on other petunias, though good drainage is beneficial. They grow from 18 to 20 inches tall when spaced at 1 foot in the garden. When spaced up to 2 feet apart, they will spread from 2.5 to 4 feet and not get quite as tall. They resist lodging and tolerate rain well. If trimming is desired in mid to late summer, the plants can be lightly trimmed (a string trimmer works well). Water and lightly fertilize after trimming to stimulate growth and flowering.
Fertilizing before planting is not necessary. However, one week after the plants have been planted, begin applying fertilizer. Use a slow release fertilizer with an analysis such as 19–5–9 at the rate of 2–3 pounds per 100 square feet of bed area. Be sure to water the fertilizer into the soil and remove any that may have fallen on the foliage of the plants. Apply fertilizer monthly throughout the growing season. Water soluble fertilizer high in analysis such as 20–20–20 may also be used with the first application being made the day the petunias are planted. Apply the water soluble fertilizer as instructed on the container.
Petunias have few serious insect or disease pests. Aphids may become a problem, but these can be controlled easily. Slugs also seem to like to feed on petunias and can occasionally be a problem. A good preventive measure for fungal diseases is to avoid watering plants from above and wetting the foliage. This can be accomplished by the installation of drip irrigation tubing in the flower bed before planting. It is also important to remember that petunias don't like water on their flowers. Note that, after a rain, petunias close up and appear to be wilted. So, when you water, use a watering wand or drip irrigation system so plants are watered well at ground level. Once water has touched the flower, it will take several days before it is fully open again, though the Tidal Wave™ flowers recover more rapidly after rains than the grandiflora types.
Tidal Wave™ Cherry and Silver also tolerate cold temperatures well. Flowering plants set out in October or early November have survived winters in north Texas as long as the soil has good drainage. Flowering will cease by winter, but will start again with the first warm days of late winter and early spring. The plants produce 18 inch mounds of cheerful color very early in the spring, a feat usually not seen until late spring or early summer in Texas gardens. Tidal Wave™ petunias are best purchased as flowering plants in containers that are 6 inches or larger.