It's hard to beat annuals from the standpoint of bold and dynamic color in the garden. Many ask which annuals work best in terms of heat and drought tolerance. Eric talks about several that he likes in his garden.
Petunias are a great choice and available across the U.S. They're one of the best summer annuals and are super tough. It's a mounding plant that spreads which means you'll get a lot of coverage. One Petunia can easily cover 2 square feet. In this video he's planting some white Petunias which are a nice, bright color in the garden. But additionally they come in pinks, purples, etc., a wide range of colors.
Marigolds are another great choice for the garden. Marigolds typically come in yellows and oranges. Eric likes using Marigolds and is going to intersperse them with the Petunias because the Marigold leaves have an oil that acts as a natural insecticide. Petunias can often get aphids but when interspersing them with the Marigolds the Marigolds will keep aphids away from the Petunias.
Vinca is another plant that is heat and drought tolerant. It is available in every conceivable color under the sun and is a very drought tolerant. It's a great container plant. If you go away for the weekend and they don't get as much water as they should, they will perk right back up when you hit them with the hose.
Eric also likes Melampodium. It looks a lot like a baby Marigold and is another great drought tolerant plant. It too is a spreading plant like the Petunia.
Salvia is another drought tolerant plant. Many are familiar with the Red Hot Poker, it's one of the most dramatic reds you can get in an annual plant.
Something he plants every year for cut flowers, flowers you can bring indoors, is annual Zinnia. Zinnia comes in a myriad of colors. Zinnias range from dwarf Zinnias which are 8-12 inches tall to plants that will grow to about 36 inches tall. They look wonderful in a vase.
No matter what part of the country you live in talk to your garden professional at your local garden center. Ask them which plants work in your part of the country, which plants are particularly heat and drought tolerant.