Even small shrubs give a live definition of the landscape’s boundaries, where one garden ends and another begins. Not only do they add form and substance to the area, but shrubs also can insert waves of color when they produce seasonal flowers, whether subtle or dazzling. Following are a few suggestions for this area.

• Red Bird-of-Paradise flowers are truly a show-stopper with their almost-gaudy color mixture of bright red, orange and yellow. Easily winter damaged, these large shrubs pop back to life each spring and bloom through autumn.

• Yellow Bird-of-Paradise, including its loose branches and multiple trunks, is often seen growing in the wild with its feathery, intense green foliage. From March to October watch for unique flowers with yellow petals from which vivid red 4-inch stamens unfurl.

• Crape Myrtle produces large clusters of blossoms in a wide array of colors including lavender, red, white or pinks. When happy with its growing conditions, this shrub can easily grow into a small, colorful tree. Check out those growing in front of the East Social Center on Abrego Drive.

• Yellowbells is a tall, lanky, native shrub with brilliant yellow trumpet-shaped flowers forming clusters at the branch ends. Cold hardy only into the high 20s, it recovers in spring and reliably blooms from April to November.

• Flame Anisacanthus, cold hardy to 5 degrees, produces numerous blazing red-orange tubular flowers with flaring ends. In summer, when loaded with color, this shrub is a magnet for visiting hummingbirds.

Mary Kidnocker is a University of Arizona Master Gardener who lives in the Green Valley area.