AUBURN UNIVERSITY, Ala. — Sunlight is essential to plant growth and landscape design. Before making planting decisions, it is important to understand and map out sunlight exposure in different areas of the yard or garden to choose appropriate plants.

Jack LeCroy, an Alabama Cooperative Extension System home grounds agent, said there is a simple and effective way to gauge sunlight exposure with a smartphone camera.

“Knowing sunlight exposure can help with planning a vegetable garden, adding a new flower bed or assessing why a plant might not be growing correctly,” LeCroy said. “Fortunately, using your smartphone camera is an easy way to assess sunlight exposure.”

Benefits

LeCroy said using a smartphone for mapping out sunlight offers several advantages.

“Assessing sunlight is convenient and accessible with your smartphone,” LeCroy said. “The time-stamped photos provide precise data, and they don’t cost extra money.”

Different plants have different light requirements. The identification tag on a plant at the garden store indicates whether a plant needs full-sun, partial-sun or full-shade conditions. LeCroy said understanding your garden’s sunlight patterns helps you choose the right plants and improve their growth.

“It also allows you to plan your garden layout effectively, placing sun-loving plants in optimal spots and providing shade for those that need it,” LeCroy said.

A firm understanding of the sunlight exposure anywhere in your yard will also save time and money when making plant decisions. LeCroy recommends evaluating exposure during both the summer and winter because the sun’s angle changes.

“I hear of many clients who buy plants two or three times until they realize that their light conditions were wrong,” LeCroy said. “This method could save you money while ensuring the plant will be happy where you put it the first time.”

Using a Smartphone

LeCroy recommends the following steps to determine sunlight exposure in the yard and garden:

Step 1: Choose Your Spot

“Watch the weather and pick a bright sunny day to evaluate the sunlight conditions. Also, make sure you will be home for most of that day,” LeCroy said.

Choose an area in the garden to assess for sunlight. This spot could be looking at just one area in the garden or it could look out over a larger area to assess more sunlight conditions. After you choose a spot, take pictures for the remainder of the day in the spot.

Step 2: Time Your Photos

“Begin early in the morning — preferably around sunrise — and take the first photo of the selected spot,” LeCroy said. “Ensure your camera’s time stamp feature is turned on in order to know where to find the time stamp related to each picture.”

Take photos at least every two or three hours. The more photos you can take, the more precise the information will be. LeCroy recommends capturing the same area from the same angle in each photo.

Step 3: Review the Photos

Review the series of photos taken throughout the day. Note the lighting conditions in each image, as the morning sun can be different from the harsh afternoon sun in the summer. LeCroy said this is important to remember when plants require partial sun in a landscape.

Step 4: Analyze Sunlight Exposure

Based on the time stamps and visual observations, determine the total hours of sunlight received by the selected spot. Categorize sunlight exposure into full-sun, partial-sun or shade.

More Information

Learn more about assessing sunlight in a garden by reading LeCroy’s publication, “How Much Sun Do I Get? Guide to Sunlight Assessment in the Garden.” For more information, visit www.aces.edu or contact your local Extension office to connect with an agent who can assist with your home gardening needs.