|Many gardeners view shade as a challenging situation for
growing plants. While some plants do not grow well in low light,
numerous others thrive under these conditions. Just as moisture,
temperature, and soil conditions may limit plant growth, the amount of
shade present may determine which plants will grow successfully. The
key is to discover which ones are adapted to the conditions in your
yard or garden. |
Landscapes change their degree of shade over time. As trees and
shrubs mature, the landscape receives greater shade. What was once a
sunny garden may evolve into a shady one. Analyze the degree of shade
in your garden periodically to determine if changes in plant materials
may be needed due to increased shade from a maturing landscape. In
addition to low light levels, plants growing in the shade must compete
with shading trees for nutrients and water, as well as tolerate poor
Lack of light:
The best way to cope with low light levels is to choose plants
that do well in less light. Plants that tolerate low light levels often
will grow more vigorously in brighter areas, provided they receive
Light shade may be described as an area that is shaded but
bright. It may be completely shaded for only several hours each day.
The sun's rays may be blocked by a wall or building for several hours
at midday, but the area is sunny the rest of the day. Light shade may
also be found in areas that receive filtered or dappled sunlight for
longer periods. Edges of shady gardens or areas under the canopy of
solitary, lightly branched trees are typical of filtered sunlight.
During the heat of summer, light shade at midday will provide a
beneficial cooling effect. Flower and foliage color may be more
brilliant when plants are shielded from intense midday sunlight.
Partial or medium shade is present when direct sun rays are
blocked from an area for most of the day. Many established landscapes
have large areas of partial shade, where sections of the yard are
shaded by mature trees for much of the day but receive some direct sun
early or late in the day. Bright, north-facing exposures may also be
classified as medium shade.
Full shade lasts all day. Little or no direct sunlight reaches
the ground at any time of the day. There may be reflected light from
sunnier areas of the yard or off light-colored walls. Dense shade
refers to full shade under thick tree canopies or in dense groves of
trees. Areas under stairways, decks or covered patios on the north side
of the house receive full shade.
Keep in mind that light patterns change with the seasons. An
area that is in full sun in summer when the sun is high in the sky may
have medium shade in spring and fall, when the sun is at a lower angle.
Study your garden through the seasons to accurately determine what type
of shade is present.
Available sunlight may be increased by selective pruning.
Removal of lower limbs on large trees may increase light levels
significantly. Large shade trees are valuable resources which in most
cases should be preserved. However, removal of diseased, unattractive
or poorly placed trees improves the beauty of your property and
increases the light available for plant growth.
Take advantage of reflected light, if possible. White or
light-colored surfaces reflect more light than dark-colored ones.
Light-colored house siding or fences may increase available light to
Plants growing in the shade often must also compete with roots
of shading trees for nutrients and moisture. Shallow-rooted trees such
as maples and willows are particularly troublesome.
Adding organic matter to shade garden soils will help. Most
woodland species are accustomed to growing in soils rich in leaf litter
compost. Raking and removal of leaves each fall in the typical
landscape disrupts this natural nutrient recycling process. If leaves
are not removed, they can mat down and smother shade garden plants, but
shredded leaves can be safely applied as a mulch. Another option is to
compost the leaves first, and apply the compost in core aeration holes
or in small pockets dug into the garden. Do not haul in several inches
of compost-rich amendment to till into soil under shade trees. Some
species, such as oaks, are extremely sensitive to changes in soil depth
within their root zone. In addition, tillage will damage many of the
tree's roots, starting a decline from which the tree may never recover.
If the gardener is patient, earthworms will eventually incorporate
surface-applied organic matter. Organic matter loosens heavy clay
soils, improving drainage. In sandy soils, organic matter will increase
the water-holding capacity. As organic matter breaks down, it also
releases nutrients to the plants.
Roots competing for limited surface water may cause shade
gardens to dry out more quickly than sunny sites during extended dry
periods. Some shade-tolerant plants are adapted to low moisture
situations, while others require moist shade. Provide water according
to the needs of the plant.
Poor air circulation:
Branches or walls that cast shade also block air movement. Poor
air circulation coupled with lower light levels means foliage of plants
stays wet longer in the shade than in sunny areas. Most plant disease
problems are worse under these conditions. Prevent disease problems by
selecting disease-resistant varieties when available. Space plants
farther apart in the shade to allow more air movement around each
individual plant. Water with soaker hoses or drip irrigation systems to
avoid wetting the foliage. Removal of lower tree limbs may funnel
breezes underneath the tree canopy, thereby improving air circulation.
Design considerations in the shade:
Bright, bold colors are less common in shade tolerant plants than in
sun-loving ones. Flowers are usually produced less abundantly in the
shade as well. For these reasons, shade gardens are often more subtle
and restful than sunny ones. Plant textures, forms and slight color
differences become more important elements of the design.
Texture has many aspects. Large-leaved plants such as hostas
have a coarse texture, while finely divided fern fronds create a fine
texture. Strong contrasts in texture accentuate their differences. Use
strong textural contrasts only where emphasis is needed.
Pyramidal or upright, columnar plant forms serve best as
accents in the shade. Rounded, weeping or spreading forms create a more
spacious effect and can be used more liberally in the design.
Glossy leaves have more impact than dull or velvety ones.
Variegated or yellow-green foliage is evident in the shade more than
solid green or blue-green foliage. Light colors -- white, cream, yellow
and pastel pink--stand out in the shade. Deep reds, blues and purples
may fade into the shade unless set off by a contrasting lighter color.
To emphasize plantings in the shade, concentrate on plants with
light-colored flowers or foliage. Hostas or any of the below plants are partial to full shade -