It's not just the amount of sun your garden receives that determines what can be grown, but also the intensity of the sun. Morning sun is generally gentler than afternoon sun. The sun in northern areas is less intense than in southern areas, which allows northern gardeners to grow shade-loving plants in somewhat sunnier locations.
Shade can vary by season as well. As the sun moves across the sky from spring to fall, an area that receives full sun early in the season may be partly shaded by midsummer, only to become sunny again in fall as the sun's angle changes. Areas under deciduous trees receive full sun in early spring when branches are bare, followed by shade in summer after leaves emerge. This makes them perfect for spring-flowering bulbs that go dormant in summer.
Listed below are the four basic types of shade and the plants that will grow best in each of those light levels.
Deep shade. Large evergreen or deciduous trees with low branches, such as Norway spruce, American hemlock, and eucalyptus, cast deep shade. The soil under these trees is often filled with mature tree roots. Only a few plants, such as moss, will grow well under these challenging conditions.
Medium shade. Medium shade is found under mature deciduous trees, such as maples, whose lowest branches are 20 feet or more off the ground. It's also the shade you'll find against the north side of a wall or hedge. These areas tend to be shaded most of the day with perhaps some dappled light in the early morning or late evening. Plants such as hostas and ferns grow well in medium shade.
Dappled shade. Small, deciduous trees, such as flowering plum; or larger deciduous trees with high, lacy canopies, such as honey locust, cast dappled shade. Although little direct sun reaches the plants underneath them, bright light filters through the canopy all day. Many plants with colorful flowers and/or foliage, such as azalea, mountain laurel, bleeding heart, ligularia, pulmonaria, and lamium, grow well in dappled shade.
Part shade. Areas in part shade receive 3 to 4 hours of direct sun a day, but not necessarily all at once. Most shade-loving plants, such as astilbe, coleus, impatiens, heuchera, and tiarella, grow well under these conditions.
