By Amy Rhoads, Paulding County Master Gardener Extension Volunteer
With Spring nearly here, the thoughts of many new plant enthusiasts turn to beautiful flowers and luscious gardens. The phrase, “right place, right plant,” is a guiding principle in any gardening effort, and brings our attention to basic horticulture practices. “Right place” refers to light, temperature, and soil conditions; “right plant” is one that is suited to a particular landscape’s environment. Determining the right plant, however, can be confusing when you shop at the garden nursery and read a plant’s light requirements on the nursery label. What exactly does full sun, partial sun, partial shade, shade, or full shade mean? How about “full sun to partial shade” or “partial shade to full shade?”
Part of the problem is a lack of consensus among growers on the meaning of more vague terms, such as “partial sun” and “partial shade.” Some use the terms interchangeably, but there is a difference. The quality of light a plant needs is not always clear from the label. Morning and evening light are less intense than afternoon. In Fall and Winter, the sun sits lower in the sky, so during these seasons, light is less intense than in Spring and Summer. Temperature and humidity will alter sunlight intensity as well. So how can you find the right plant?
Before purchasing, observe both the quantity and quality of light in your spaces. Do they receive morning, afternoon, or evening light? Is it direct, indirect, or dappled? Keep in mind that as spring ushers in, so do the canopies of surrounding trees; what may get full sun in Winter could be partial sun or partial shade in Spring and Summer. Tree growth over time or removal will alter light exposure as well.
Knowing the quantity and quality of sunlight, then, use the plant tags as a guideline only. Generally, nursery tags will list one of the following terms, but it is always best to double check extension recommendations for light requirements. Many can be found in the Landscape Plants for Georgia Publication: https://secure.caes.uga.edu/extension/publications/files/pdf/B%20625_6.PDF
Full sun. Six or more hours of direct light, preferably the majority of which come from morning and early afternoon sun. Some plants, such as salvias and succulents, can take heat, but many tagged as “full sun” are heat sensitive.
Partial sun. Four to six hours with an emphasis on morning and early afternoon sun.
Partial shade. Two to six hours with an emphasis on afternoon and evening shade.
Full shade. Less than 4 hours, preferably morning, filtered light the remainder of the day
Full Sun to Partial Shade or Partial Shade to Full Shade. These terms imply that the plant is adaptable to the range specified, but it is likely that the first part of the term is closer in accuracy. For example, if the tag states “part shade to sun,” then the plant probably prefers more shade but could tolerate morning sun (but definitely not afternoon sun). Again, do your own research. UGA Extension’s publications page has a wealth of research-based and reliable information. https://extension.uga.edu/publications.html
While some plants can adapt to moderate levels of either sun or shade, others have specific light needs. One option is to test several locations over the course of several weeks. Simply keep the plant in its nursery pot, being careful that it does not stay too wet or too dry, and watch how it responds to living in that location. This process can seem tedious, but it can also be interesting and informative.
