Sow one kind of annual and watch it go wild
In Fort Collins, Colorado, Bob and Bev Bacon's backyard resembles a sunny mountain meadow overflowing with wildflowers. Three years ago, it was sown with a mixture of Coreopsis tinctoria, also known as calliopsis. Each year since, this easy-to-grow annual has reseeded itself. Reaching 1 to 3 feet tall, it bears abundant 2-inch-wide star-shaped flowers in shades ranging from a yellow-and-burgundy bicolor to solid maroon.
If you'd like to try a planting like this, wait until after the last frost in your area. This sun lover prefers well-drained soil and tolerates drought. Direct-sow seeds over loosened soil; barely cover seeds with dirt, or press them lightly into soil. Keep the area moderately moist until seeds germinate, usually within 10 days. When seedlings reach about 2 inches tall, thin to about 8 inches apart. The Bacons water established plants twice a week. Deadheading the spent blossoms helps prolong bloom time. Toward the end of the season, let some blooms set seed to carry on the show next year.
Ed Hume Seeds sells packets of C. tinctoria mixture. Wildseed Farms (800/848-0078) sells Radiata Mix.