Sun Mapping Your Yard to Start a Garden

Despite what it sounds like, sun mapping is not making a map of the Sun. A sun map is a map of the sun’s presence in your yard. Simply put, you observe and map to assess how many hours of sunlight each area of your yard receives in a given day.

Sun mapping your garden will help you buy the right plants and place it in the right location. Plants grow best if you give them the right amount of sun exposure and the only way to do this is to know how much sun each of your garden spaces gets.

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Why Make a Sun Map of Your Garden?

Sun mapping your garden will help you select the right place for each plant.

You just bought a new plant that likes to grow in shade and you are walking around your garden looking for a place to put it. Obviously, you are looking for a shady spot, but if it is very cloudy, you can’t tell which part of the garden is shady – it’s all shady today.

Even if the sun comes out how do you tell the difference between shade or part-shade? You can’t unless you stand there all day.

Many gardeners plant in spring or fall when trees do not have leaves. It is very hard to identify a shady spot at this time of year.

As a new gardener or an experienced gardener in a new location, it is very helpful to have a sun map of the garden. Then when you are looking for a place to plant your new seedlings, you won’t make a mistake.

Make A Map of Your Property

This is much easier than it sounds. Take a piece of paper and sketch your property. If you aren’t sure where to start do a quick google search for your property on google maps.

Graph paper is the easiest to use but any sheet of paper will work. It is helpful to get things to scale but that is not necessary. What is important is that you can easily identify each existing garden area as well as any potential future gardens. It is a good idea to include the house, shed, patio, fences, etc, because these will help you identify the location of the gardens.

Here is mine. It could be neater and more to scale, but that is not necessary. Once your map is complete make five copies.

Measuring Sunlight

Pick a day that is sunny with limited cloud cover. Go into your yard and take note of where the sun hits the ground directly and where you have a shadow. A shadow line is a separation between these two areas.

Take one of your maps, draw in all of the shadow lines and then shade in the shadow areas.

Repeat this 4 times during the day to see how the shadow changes throughout the whole day. Using 9:00, 12:00, 3:00, and 6:00 works well. Make a map each time you do it. Make sure you record the time at the top of every map.

Some people record values every hour, but that is not necessary. We don’t need that kind of accuracy to know where to put plants.

Best Time of Year

Shadows change with the time of year and this effect depends very much on where you live. There is almost no change close to the equator. The sun rises and sets in the same spot all year long and therefore the shadows are the same all year long.

As you move away from the equator, the point at which the sun rises is different throughout the year. The location at midday also changes. In my garden, the sun is almost overhead at noon in the summer, but it’s much nearer the horizon in winter. This seasonal change means that shadow lines also move as the season changes.

If you are near the equator you can measure shadows at any time of year, provided deciduous trees still have their leaves. For areas that see a lot of seasonal change, it is best to make the measurements near mid-summer.

Prepare a Final Sun Map

Take the 5th copy of your map and place the other 4 maps around it. Pick a point in your garden and check all 4 of the maps to see if it is sunny or shady.

If at least 3 of the maps show it as sunny – mark it sunny.

If at least 3 of the maps show it as shady – mark it shady.

If it is neither sunny nor shady, mark it as part-shade.

You can use colored pencils to color code things, or just add letter designations – whatever works for you.

Now repeat this process for other areas of your garden. When you are finished, your whole garden will show one of three designations – sun, shade or part-shade. You are now ready for planting.

I keep my final sun map in my garden planner so that I can reference it when starting a new garden bed or garden planning.

Diving Deeper

Learning to make a sun map isn’t difficult, but it does require a bit of time and observation. I first learned about creating sun maps in Amy Stross’s book The Suburban Micro-Farm. Amy blogs at the Tenth-Acre farm, she doesn’t live on a suburban micro-farm anymore but, she has fantastic articles and resources for using every square inch of your yard. On her blog and in her book she gives a more in-depth instruction for sun mapping and also talks about mapping how water moves across your yard. This is important since there certainly are many plants that do not like their “feet wet.”

So, as you jump into making your sun map, give yourself grace and time. Once you have your map, start thinking about all of the different things that you could plant and grow. Check out our Garden Planner & Journal if you are looking for an easy way to stay organized in your garden planning and make the most of your garden space.