Plants like sun or shade, more or less; But which?
We have all made the mistake of putting a sun-loving plant where it receives too much shade or a shade plant where it gets too much sun.
The amount of light available to a particular plant is extremely important for it to thrive and often too much light can be devastating. Usually, the tag on a plant in the nursery lists the plant’s light requirements, but you may not be sure about choosing the right location for it in your particular outdoor spaces.
Remember that light also changes with the season, so the area may be shady now, but sunny as we get to midsummer and vice versa as sunlight patterns change. Landscapes also change their degrees of sun and shade over time as they mature.
Another factor this year is that you may have had shade before, but the tough blows of the past winter’s storms and record low temperatures may have, unfortunately, modified your landscape. This would be a perfect time to move many of your shade-loving perennials that will no longer be in shade to another area of your garden. I know I have had to do this in my own gardens this year.
Heat and humidity also can affect the amount of direct sun a plant can take. In Oklahoma, our late summers can be brutal. So, if a plant has a tag on it that says “full sun” that doesn’t necessarily mean the plant will actually tolerate the full sun in Oklahoma.
With a few exceptions, most plants will benefit from late afternoon shade in our hot summers. Oklahoma State University Extension has an excellent online award winning publication called “Water Efficient Landscapes for Oklahoma,” which you can purchase or read online that is helpful in selecting heat- and drought-tolerant plants.
It can be confusing to a gardener deciding what constitutes full sun, full shade, and partial sun or shade. Before you select plants for your garden or landscape, it is important to understand how we label light conditions in outdoor spaces in gardening terms.
Generally, in horticulture, we would call six or more hours of direct sunlight per day a full-sun site. This doesn’t need to be continuous, for example, there could be four hours in the morning, shade at midday, and then a couple of hours of sun in the afternoon. Almost all vegetables want full sun, and full-sun annual flowers include petunias, zinnias, and marigolds. Some popular full-sun perennials include all the perennial Salvias, Gaillardia and Rudbeckia.
In gardening terms, partial sun usually means between four and six hours of sun a day. Partial shade is two to four hours of sun per day. Shade would mean less than two hours of sunlight a day. Annuals that love the shade include Begonias, Caladiums, and Impatiens. Example of perennials that are shade loving include Columbines and Hosta Lilies.
Before buying plants, it is a good idea to measure the amount of sun your garden receives. You can do this by planning to spend a day you will be gardening making notes of sun patterns in different areas of the garden in mid to late spring.
When selecting plants for any location, also consider all other requirements for their success like soil type and pH preference, moisture needs, possible pests and diseases, and hardiness zone for trees, shrubs and perennials.