The yellow bells plant (Tecoma stans), also known as esperanza and yellow trumpet flower, produces bright yellow flowers that add lots of color to gardens in warmer climates in USDA hardiness zones 9 to 11. Rather easy to care for, the sun-loving plant also makes a great container specimen when grown in cooler climates. Consider placing containers of yellow bells around the pool or near a porch, patio or deck to enjoy the bright color all summer long.
Wild yellow bells grow on rocky slopes near San Antonio, Texas north through New Mexico and Arizona and all the way east to Florida. The small to medium-sized shrub grows up to 5 feet tall and 4 feet wide, forming mounds of attractive green, glossy foliage. The sun- and heat-loving plant produces fragrant, bright yellow, bell-shaped flowers that bloom all summer long. Butterflies, bees and hummingbirds find the nectar from the blossoms highly attractive. Flowers are followed by seed capsules growing up to 6 inches long.
Yellow bells prefer well-drained soil that receives full sun. The plants also thrive if they receive plenty of morning sun and afternoon shade. In preparation for planting, till the soil to a depth of 8 to 10 inches and work 3 or 4 inches of organic matter into the soil if it drains poorly. Dig the planting hole two to three times the size of the root ball, but make sure to place the plant at the same depth as it was in the container it came in.
Consider adding a slow-release 19-5-9 fertilizer when preparing the soil for planting. Otherwise, the plant grows best when fertilized every 4 to 6 weeks with light fertilizer applications.
Water yellow bells regularly from spring through fall to keep the plants blooming all summer long. In the heat of the summer, the plants require more frequent watering. To keep flowers blooming, remove the seedpods as soon as they form. Use the seeds for planting the following spring. As winter approaches, protect the semievergreen plants from frost to encourage the plants to grow and bloom the following spring.
Yellow bells make a great fast-growing container plant, especially in cooler climates. Make sure the containers drain well. Plan to apply a diluted water-soluble 20-20-20 fertilizer every other week. Controlled-release fertilizer also works well. If watering daily, the plants may require more frequent fertilization. To keep the plants blooming all summer, place the containers in full sun from spring through the fall.