Lighting conditions in a garden are influenced by many things that change the light from one thing to another. Plant a large tree and a sunny area quickly becomes shady. Prune branches away and a shady spot suddenly has more sun. Flowers that like sun and shade adapt to the changing conditions they encounter in the garden landscape.
Bluebell bellflower (Campanula rotundifolia) is also known as bluebell-of-Scotland and harebell. The plant is hardy in U.S. Department of Agriculture Plant Hardiness Zones 4 to 9 and grows from 4 to 15 inches tall. The plant produces round, base leaves and blue-violet, bell-shaped flowers that grow as singles or in clusters at the tips of the stems. The flowers bloom from June through September and are a favorite of hummingbirds. Plant bluebell bellflower in full sun, partial shade or full shade and in soil that is sandy, dry and well-drained.
Shellflower (Chelone obliqua) grows from 2 to 3 feet tall and 1 to 2 feet wide with lance-shaped, dark-green leaves. Rose-purple, pink or white flowers resembling a snapdragon grow in stiff clusters at the tips of the stems and bloom in July and August. Plant shellflower in full sun or partial shade and in soil that is moist to wet. The plant is hardy in USDA Zones 3 to 9.
Rock cotoneaster (Cotoneaster horizontalis var. perpusillus) likes full sun or partial shade and a soil that is moist, loamy and well-drained. The plant grows from 1 to 2-1/2 feet tall and 5 to 8 feet wide. Pale pink flowers bloom in May and June, giving way to scarlet-colored berries in late summer and fall. Small, round, dark-green leaves turn reddish-purple in the fall. Rock cotoneaster is hardy in USDA Zones 4 to 7.
Whirling butterflies (Gaura lindheimeri) is also known as white gaura and butterfly gaura. The plant grows from 2 to 4 feet tall and 2 to 3 feet wide with thin, wiry, hairy stems and 1- to 3-inch long, spoon-shaped leaves. Flowers grow taller than the leaves in spike-clusters 8 to 24 inches long, starting out white in the morning and turning a rose-pink by the end of the day before dropping off. New flowers bloom continuously throughout the season. Plant whirling butterflies in full sun or partial shade and a soil that is moist to dry and well-drained. The plant is hardy in USDA Zones 5 to 9.