• Texas is a large state known for its hot, humid summers. Despite the Texas heat, a variety of flowers can grow and thrive. These tough flowers are native to Texas, which helps them withstand the heat better than non-native plant species. Covering hardiness zones 6a to 9b, there's a flower for every zone to brighten those long summer days.
  
  

Mexican Petunia

• Mexican petunia is a heat-tolerant, evergreen perennial that can withstand the heat of Texas summers. It grows in almost any type of well-drained soil in full sun. Mexican petunias can be used as a groundcover in hardiness zones 8 to 10 and possibly in zone 7, if the plants are protected and mulched. From early summer until the first frost, the pink, violet, blue or white flowers bloom on the end of strong stalks up to 3 feet tall. The flowers of the dwarf Mexican petunia sit slightly above the leaves at 8 to 12 inches high. In the sun, the dark green leaves have a blue metallic color, making the color of the flowers stand out, which attracts a variety of butterflies.
  
  

Blackfoot Daisy

• The scent of honey fills the air around Blackfoot daisies, drawing bees, butterflies and other nectar-loving insects. The creamy white, notched petals surround a center of tiny, star-shaped, yellow flowers. Blackfoot daisies bloom from March to November in a round, bushy, compact mass standing 6 to 12 inches tall and 1 to 2 feet wide. The flowers stand out against a backdrop of slender, dark green leaves. The ideal environment for growing these sun-loving flowers is soil that is slightly dry and well-drained. This heat- and drought-tolerant plant is a good addition to a rock garden in hardiness zones 5 to 9.
  
  

Celosia

• The group of celosia flowers are comprised of three well-known types: Plumosa, Cristata and Spicata. Each type has a different appearance, making them easily identifiable. Plumosa looks like a large feather duster with a pointy tip. Cristata varieties may look like a roosters' comb, a brain or a two-tone French ribbon with folds that are light-colored inside and darker on the outside. A Spicata flower looks like a stalk of wheat. Celosia is available in vivid colors such as rose, yellow, pink, purple, cream, red and orange. Celosia is a tender annual in hardiness zones 1 through 9b, and a perennial in zones 10 and 12. The hot, humid weather during the summer in Texas doesn't bother these flowers. They can be as small as 4 inches or grow to over 3 feet tall. Celosia thrives in full sun and in almost any type of well-drained soil, as long as it receives enough water.
  
  

Black-Eyed Susan

• Once established, black-eyed Susan can survive drought unscathed, even growing in full sun. The 2- to 3-inch wide bright yellow flowers surround a dark brown cone. They bloom from June to October on the ends of stems measuring 1 to 2 feet tall. The leaves and stems have tiny, bristly hairs on them that give the plant a rough, coarse texture. The hottest parts of Texas don't faze these large flowers, which attract wildlife such as bees, birds and butterflies. Black-eyed Susan flowers are hardy in zones 3 to 9.