What Does Part Sun Mean?
What exactly does Part Sun and Part Shade Mean?
It is important for your plants that you understand sun requirements. There are some standard principles you can use as a guide to sun requirements.
Full Sun: At least 6 hours of direct sun. But most gardeners know that there is a big difference between giving a plant 6 hours of sun and giving a plant all day sun. Keep in mind that 6 hours is bare minimum for a full sun plant, 8 hours is better. There are many plants that love all day sun but they need to receive regular watering and enriched soil. Some examples are: Roses, which will want regular watering; annual Geraniums, petunias and many other annuals, which will want frequent watering; and many perennials such as peonies, asters, delphiniums, heuchera, that will want regular watering. If your plants will receive all day sun and not receive regular watering, then be sure to select heat and drought tolerant plants.
Part Sun/Part Shade: These are essentially the same, 3-6 hours of sun each day. Generally if the requirement for a plant is listed as Part Sun the plant will prefer closer to 6 hours of sun and can likely tolerate afternoon sun. If the requirement for a plant is listed as Part Shade, the plant will do fine with closer to 3 hours of sun and will likely prefer morning sun.
Dappled Sun/Shade: Sunlight that is filtered through the leaves of a tree. The plant will receive sunlight in brief intervals as the sun moves over the tree, preventing the plant from getting too warm.
Light Shade: This term, or filtered shade, is sometimes used and means a total of 2-3 hours of sunlight at intervals through a tree canopy. Essentially the same as dappled sun.
Full Shade: This term is really a misnomer. Full shade does not mean no sun. A full shade plant can do with less than 3 hours of direct sun and should receive some filtered sun through the day.
Deep Shade: In the home landscape, these are the areas blocked by buildings that receive no direct sunlight. This may be the north side of your home, a recessed entry area, or narrow passage between buildings. If the area is at least bright, you may be able to grow a few things such as ferns, Irish moss and lily of the valley. Fortunately there are some very interesting ferns, including the Japanese painted fern. Some shade plants may grow very slowly, or at least stay alive, but would not flower.
No matter what the sun requirement for a specific plant, the time of the day the plant receives sun can make a big difference. Morning sun is cool and afternoon sun is hot. A plant can take a lot more morning sun than afternoon sun. Plants in afternoon sun will generally require more frequent watering.
Generally, the more sun a plant receives, the better it will flower. But not all blooms will hold up to afternoon sun and the petal color will fade or the blooms will wilt. For all day sun that includes the hot afternoon sun, look for plants that are not only heat and drought tolerant, but also with flowers that will stand up to the heat. Native perennials are often good choices, with many cultivars and hybrids to choose from.
In regions with hot summers, you may need to counteract the effects of the hot sun. Where afternoon sun is not present, place your plants close together to create at least ground shade. This will help keep the soil cooler. Ground cover plants and mulch will also help, and of course, regular watering.
There are also a few things you can do where shade is more dense than you would like. First and foremost, have your trees thinned out. Removing select inner branches is not only good for your tree, you will let more sunlight to under plantings. You can also space your plants further apart to make sure the entire plant is getting as much sun as possible, rather than being shaded by a closely planted neighbor.
Where afternoon sun is too hot, of course you can plant a tree. It doesn’t have to be a big shade tree though. A well placed evergreen or small ornamental tree can give your plants just the short break they need from the hot sun.
But the best thing you can do is select plants appropriate for your light conditions. A plant you love that does not thrive because it is not receiving the right amount of sun will only disappoint.