Or “Sun, Part Sun, Part Shade, Full Shade – What Does It All Mean?”
By The Kennedy Team
A shade garden can be a wonderful retreat from the late summer heat. Shade gardening should be looked at as an interesting challenge instead of an obstacle. While shady areas can limit your plant selection somewhat, many of the most beautiful plants in the world grow in darker areas.
In shady spots, the colors, textures, and patterns of foliage become more important because you can assume that there will be fewer showy flowers in a shade garden than in a full sun garden. Astilbes are on the list of perennials that are the exception to this rule. Rhododendrons and Mountain Laurels are two shrubs that can provide color. And, if you have the space for them, Redbuds and Dogwoods are two understory trees with plenty of color.
Colorful foliage plants can play an outsized role in shade gardens. Perennials like Hosta, Heuchera, Hakone grass, and Sedge make a garden come alive with color even when they are not in bloom. Think of white as a color in shade gardens; variegated varieties of Hosta, Solomon’s Seal, Lamium, Ajuga, Liriope, and Brunnera add striking accents. The textured and lacy foliage of Ferns, Astilbe, Actaea, and Corydalis add interest, especially when planted in front of plants with big, bold foliage such as Leopard Plant, Hosta, Yellow Wax Bells, and May Apple.
How Much Sun/Shade Do I Actually Have?
Sunlight (or lack thereof) varies throughout your yard. Sunlight will also vary by season and by the time of day. Summer is the best time to judge how much sunlight you have in each area of your yard because the sun is at its highest and temperatures are at their hottest. At the same time, deciduous trees will be fully leafed out.
Plants can be roughly divided into shade-loving or sun-loving. For many gardeners, these two rough groupings provide enough information to allow them to purchase the right plants for their gardening projects. For those who want additional detail and nuance, it is good to know that light requirements for plants range from Dense Shade to Full Sun. (See details below.)
Keep in mind that most plants have a range of light conditions in which they will thrive. For example, Daylilies are typically considered a Full Sun plant, but their light requirements range from Full Sun to Part Shade. They will perform very nicely with as little as three hours of direct sun or as much as a full day of direct sun. Tree Peonies are another plant that is typically thought of as a Full Sun plant, but they can also take a fair amount of shade.
Most plants are going to be in the shade for at least some portion of the day. Even Full Sun plants will thrive with some shade, as long as they get a total of six or more hours of direct sun.
A plant located in an area that does not provide its ideal quantity and quality of light might not perform at its very highest level, but it might very well still perform adequately for your needs.
Keep in mind that afternoon sun is hotter than morning sun. Morning sun, which is cooler and less intense than afternoon sun, is easier on shade loving plants. Shade-loving plants will scorch if exposed to too much intense afternoon sun.
Take into account your entire site. Shade is not just a result of trees, but also buildings, fences, and other structures that cast shadows or block the sun’s rays. Direct sunlight means that there is nothing between the plant and the sun. Trees with high canopies or sparse foliage as well as latticed fences or walls can provide dappled shade that protects shade-loving plants from sun scald, while still providing plants that need it enough light to flourish.
When planting in Dense or Full Shade, lack of moisture in the soil can be an issue. Trees or structures can prevent rain from reaching the ground, and tree roots can compete for that moisture. Plants in Dense or Full Shade should not only be shade tolerant but also drought tolerant unless supplemental water will be applied.
Light Requirements Defined
Dense Shade can be defined as an area that receives no direct sunlight and even indirect light seldom reaches the ground. Examples of Dense Shade locations include areas under evergreen trees or other trees or shrubs with a thick canopy and low branches. It can be also be found under overhangs of buildings, under decks, and in dark corners and passages between houses. Areas on the north side of buildings or walls can also be Dense Shade areas.
Full Shade can be defined as an area that receives less than 1 hour of direct sunlight each day. A Full Shade area might be in full shade part of the day, dappled sun part of the day, and full sun for an hour or less. Full Shade plants prefer little or no hot afternoon sun.
Part Shade can be defined as an area that receives 1 to 3 hours of direct sun each day. Part Shade plants prefer little or no hot afternoon sun. Part Shade is good for many flowering shrubs that will produce more blooms with a little sun. This includes plants such as rhododendrons and azaleas. Macrophylla hydrangeas can stand a fair amount of sun (more than three hours a day), but prefer to be in the shade in the afternoon. Areas on the east side of buildings or walls are often Part Shade areas.
Light Shade can be defined as an area that receives 3 to 4 hours of direct sun each day.
Part Sun can be defined as an area that receives 4 to 6 hours of direct sun each day. Part Sun plants can tolerate hot afternoon sun.
Full Sun is direct sun for 6 or more hours per day. In nature, full sun would be a meadow or open prairie space. Full Sun plants can tolerate direct sunlight for an unlimited number of hours each day. Full Sun plants can also tolerate some shade, as long as they get six or more hours of full sun over the course of the day.
Installing a Shade Garden
There are many considerations when designing any garden. In addition to understanding the quantity and quality of light available, soil quality and moisture content are critical components of successful gardening.
Good quality soil is an essential element for long-term success in your garden. If you have an unplanted area to begin with, you can make things easier by preparing your soil before beginning to plant. Add organic matter and work it into the top six inches of soil for a healthy garden. If you are adding plants to an area that already has root systems, plants, or groundcover, add organic material when planting each plant. Compost, peat moss, or aged, composted manure all improve the condition and fertility of your soil.
Organic material added to the soil will also help retain water for use by plants as needed. As noted above, areas of dense shade may require you to plant drought resistant plants unless you have an irrigation system. Drought-resistant shade plants include Ajuga, Anemone, Astilbe, Brunnera, Epimedium, Helleborus, Hosta, Lamium, Liriope, Tricyrtis, and some ferns, among others.
Most of all, plan to experiment and have fun! You will be sure to discover some new favorite plants once you start looking. Kennedy’s staff members are always available to help you select the best perennial plants for your landscape.