Sun Map

Creating a sun map of your yard may surprise you. And your plants will thank you.

December artichoke at 9AM (Kate Russell)

December artichoke at noon (Kate Russell)

Sun-loving tomatoes will never produce abundant fruit if they don’t get enough sunlight, while tender lettuces may bolt before producing much in the way of salad greens if they get too much sunlight. Without enough sunlight, plants die. Without the right type of sunlight, plants fail to thrive.

Just as a soil map can help you take better care of your plants, creating a sun map of your yard will help you see where different types of sun exposure occur at different times of the year. This will help you place plants where they can grow and thrive.

How to make a sun map

Making a sun map of your yard is not hard, but it does take some time - a full year, in fact. That’s because the angle of the sun changes from season to season and you will need information from each season to make an accurate sun map. The easiest way to create a sun map is to start by taking photos in the morning, midday, afternoon, and early evening in each of the four seasons. To make this job easy to remember, you might want to set aside the spring and autumn equinoxes and the summer and winter solstices for this task. If you aren’t that motivated, you can do it in spring and summer.

Select viewpoints that give you the widest perspective on your property. You might want to position a lawn chair, plant stake, or other marker at each of your shooting spots so that they remain consistent, but this isn’t necessary. The important thing is to get out there and take the photos.

To put those photos to work, you can use graphics layering software (beyond me), you can draw a sketch of your property, or use a printed Google Maps screenshot of a terrain view of your property. I start with the terrain view and then trace the image. These images are very handy, I keep copies in my file cabinet. The next step is to decide on a key for each type of sun exposure.

Google Maps terrain view of property (Kate Russell)

Tracing of the same property image (Kate Russell)

Sun exposure

Morning sunlight and afternoon sunlight are different. Sunlight in summer and winter are different, too. Sun exposure is classified this way:

• Full sun - 6 to 8 hours of direct sunlight
• Partial sun - 3 to 6 hours of sunlight in the afternoon
• Partial shade - 3 to 6 hours of morning sun with protection from afternoon sun.
• Full shade - bright dappled sun all day or less than 3 hours of direct morning sun.

These terms do not give you a ton of information, but they give you enough to make better decisions about where you grow your plants.

Your key will use different symbols to indicate different types of sun exposure. For example, your key may use dots for full sun, dashes for partial sun, slashes for partial shade, and tiny triangles for full shade.

Take your property map and your photos and pencil in the different sun exposures, using your key. For more helpful information, use different colored pencils for each season. This will help you see how things change over the course of the year. Or, you may prefer creating a different sun map for each season and saving the colored pencils for the different sun exposures. How you do it doesn't matter. That you do it does matter.

Raised beds at 9AM in May (Kate Russell)

Raised beds at 11AM in May (Kate Russell)

Why map the sun?

The most important benefit of a sun map is that it helps you position plants, raised beds, and structures, such as garden sheds, properly in the first place. If everything is already in place, a sun map will help you select the best locations for annual plants. A sun map can also help you figure out why fungal diseases may keep occurring in certain areas. Locating plants prone to fungal disease in areas where they will receive morning’s first light will help dry leaves as quickly as possible. And if your summers are like mine, you can reduce the afternoon scorch by locating plants where they will receive some protection in the afternoon.

Planting bed at 9AM in February receives full sun

The same bed at 10AM in May

The same bed at noon in July

Sunlight calculators

Retailers are happy to sell you a physical sunlight calculator and apps for your phone, but these are not useful. You can see for yourself if an area is shaded or not. Much like OTC soil tests, the information these products provide is not detailed enough to actually mean anything.

It is all too easy to forget about the effect of seasons on sun exposure. As neighboring trees leaf out or drop their leaves, nearby plants can find themselves in a completely new environment in a short period of time.

Creating a sun map may also give you a better view on how your plant population changes over the seasons. It's pretty amazing stuff!