Perennials are plants that live for two years or more. Shrubs and trees generally keep growing; flowering perennials, on the other hand, typically grow and bloom in the spring and summer and then die back or go dormant in the fall and winter, only to return the following spring from root stock. While most perennials thrive in full or partial sun, several varieties do well in full shade and are thus popular garden plants for beds that are under trees or in covered patios.
Fuchsias are hardy shrubs with flowers shaped like bells rimmed by long, slender sepals. The four shorter petals that make up the inner "bell" and the longer sepals that cover the bell like a canopy are typically of complementary colors, such as purple and pink or pink and red. Most of the 100-plus species of fuchsia are native to South America and thrive in tropical climates. Fuchsias are often used in gardens under trees as decorative specimens alongside ferns and other green, non-flowering perennials.
Forget-Me-Nots are dense, low-growing plants that are a staple of shade gardens the world over. They have carpets of small green leaves punctuated by tiny blue flowers, each with five petals. They can tolerate full shade or partial shade and are fast growers.
The plantain lily, also known as "hosta," has large clumps of lush green leaves and flowers that grow on spikes. Flowers are fragrant and typically come in the late summer; the leaves, which often are heart-shaped, stay green year-round. Hostas are easy to grow and like shade, which mimics their natural habitat, the forest floor.
Impatiens are fast-growing flowering plants with small heart-shaped leaves and brightly colored flowers that range in color from white to pink, salmon, orange and red. They propagate exceptionally fast and grow well in mass plantings. They literally shrink away in sun and thus are ideal for full-shade gardens; they often are planted in the foreground, behind fuchsias and ferns.
These Asian exports are known for their large clusters of tiny flowers, generally either pink or blue, depending on how much iron there is in the soil. The clusters of flowers resemble pom-poms and can be six inches or more in diameter. Hydrangeas are a mainstay of old-school gardens and while they can stand a little sun they prefer shade.