Whether you call them gloriosa daisies, black-eyed Susans or rudbeckias, one thing is certain: they are among the showiest plants in the summer garden. In last summer’s trials it was the Denver Daisy that caused the commotion in the gardening public.

But last season’s trials weren’t the only predictor for this showy new rudbeckia; it was the celebratory flower chosen for Denver’s 150th birthday in 2008. Botanically speaking, Denver Daisy is a rudbeckia hirta and is a cross between the native species and a prized selection known as Prairie Sun.

The flowers are large, 6 to 8 inches, and feature golden yellow petals with a blaze of red around the brown cone. The plants grow upright, easily reaching 24 to 30 inches and are well-suited to cutting for the vase. You’ll also notice they are favorites for bees and butterflies.

Rudbeckia hirtas have the opportunity to be short-lived perennials, but most gardeners treat them as annuals. But even treated as an annual like a petunia or marigold, rudbeckias still represent one of the best buys for your gardening dollar.

Another selection getting raves is Tiger Eye, the first F1 hybrid rudbeckia. The flowers are smaller, reaching around 3 inches, but the 24-inch-tall plant produces them in larger quantities than you see on many black-eyed Susans. You’ll also notice that the flowers are semi-double with light yellow petals that darken to gold with even a little hint of orange toward the cone.

Tiger Eye is also well-suited in designer artistic containers. Try using it as the center or thriller plant, and partner it with complementary colored flowers like blue petunias or torenias. Add a touch of a grassy element and you’ll have a stunning decorative piece for the porch, patio or deck.

Rudbeckias perform best in full sun with fertile, well-drained soil. Tight, compact clay or soggy soil yields less than satisfactory results. So if you find yourself in this situation, incorporate 3 to 4 inches of organic matter like compost, peat or humus before planting. While many plant shoppers have a tendency toward instant gratification and buy them already in full bloom, you’ll find them acclimating to your landscape better if you buy a transplant just comprised of healthy foliage that is still actively growing.

Space your plants 18 to 24 inches apart, planting at the same depth they are growing in the container. Since these are tall plants, you’ll want to place them to the middle or back of the border. Plant them in bold drifts rather than spot planting. They are the quintessential cottage-garden plant and look great in combination with spiky blue flowers like tall Mystic Spires salvias or Angel Mist angelonias, and purple coneflowers. For the front of the border use blue or violet verbenas like Tapien, Lanai or Homestead purple.