Sun Mapping Your Garden the Easy Way

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Robert Pavlis

Sun mapping your garden will help you buy the right plant and place it in the right location. Plants grow best if you give them the right amount of sun and the only way to do this is to know how much sun each of your garden spaces gets. In this post I will show you a very easy way to get this information and develop your own personalized sun map.

Sun Mapping Your Garden The Easy Way
Sun Mapping Your Garden The Easy Way, Aspen Grove Gardens

KISS in the Garden

KISS stands for Keep It Simple Stupid. I am always amazed that some gardeners go out of their way to make our hobby difficult. Things work so much better, and are more enjoyable, if you keep it simple.

There are some electronic gadgets, like the Sunlight Calculator,ย  available that claim to make sun mapping easy, but they simply are not needed. All you need is paper, a pencil and your hand.

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.

Food Science for Gardeners, by Robert Pavlis

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 special purchase, you won’t make a mistake.

YouTube video

Sun, Shade, Part-shade and Part-sun

Plant labels only give approximate sun requirements
Plant labels only give approximate sun requirements

Have a look at a plant label, or check a plant on line and look for the light recommendation. In virtually all cases the best information you get is sun, shade, or part-shade/part-sun. Nobody tries to fine tune this to give you the exact hours the plant likes because that is too difficult, and it does not matter. Plants are not that fussy and other factors like water can be more important.

What is the difference between part-shade and part-sun? Some people try to define these more precisely but it is really not necessary. I consider them to be the same thing – use KISS.

Sun is at least 6 hours of direct sun (no shadows).

Part-shade is 4-6 hours of direct sun.

Shade is less than 4 hours of direct sun.

All you need to do, is assign one of these categories to each area of your garden.

Make A Map of Your Property

This is much easier than it sounds. Take a piece of paper and sketch your property. Graph paper is easiest to use but any sheet of paper will work. It is helpful to get things in 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 gardens.

Microbe Science for Gardeners Book, by Robert Pavlis

Here is an example of one I did. It could be made better with a tape measure and ruler, but that is not necessary. Make five copies of the map once it is complete.

Example property Map by Garden Fundamentals
Example Property Map

Measuring Sunlight

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

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

sun map for 9:00 am
Sun map for 9:00 am, shaded areas have a shadow

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.

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 its much nearer the horizon in winter. This seasonal change means that shadow lines also move as the seasons change.

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 or 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.

Final sun map - brown is full shade, orange is part shade and yellow is full sun
Final sun map – brown is full shade, orange is part shade and yellow is full sun

How to Create a Beautiful Shade Garden

Now that you know where your shade garden is, you will enjoy this video.

YouTube video

If the above link does not play try this one: https://youtu.be/gXt0pzZjXSI

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Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

24 thoughts on “Sun Mapping Your Garden the Easy Way”

  1. I have a dry back yard in summer, where I grow vegetables the remainder of the year. I live in N. America and don’t irrigate my garden, so in summer my vegetables go to seed and dry up. The seeds blow around and they seem to grow all over the backyard, even in the areas that are mostly shady in winter. My mustard plants are quite high, so maybe they have an advantage with getting some sun, and are therefore more flexible. A sun map isn’t on my list of things to do for my vegetable garden, but for my husband with the decorative front yard it would be very helpful, it seems.

    Reply
  2. Hi what happens if you are Northern hemisphere not near the equator and didn’t sun map your garden last summer but keen to plant now thanks ๐Ÿ˜€

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    • You can only sunmap when the sun is there. However, if you know the movement of the sun across the sky, you can guess close enough.

      Reply
  3. You lost me at โ€œ Go in the garden and take note of where the the sun hits the ground directly and where you have a shadow. A shadow line is the separation between these two areas.โ€ What the heck does that mean? ๐Ÿ˜ณ

    Reply
  4. I garden under black walnuts and a Norway maple, and I find the soil under the black walnuts is fairly moist and I rarely encounter a tree root when putting in spring bulbs or other plants. Having a garden under the Norway maple has been VERY hard. Even plants that supposedly like dry shade have stopped flowering and “shrunk” – if not succumbed altogether. Against your advice, I did add a layer of soil when creating the garden under the Norway maple – about 10” or so… but my garden was likely only 15-20% of the surface area under the drip line. It was a BIG tree – 2 plus feet diameter trunk, and I doubt covering a small portion of the roots harmed it. I made sure the soil level immediately around the trunk was not raised. That being said, within 2 yrs, the Norway maple’s roots had fully invaded everywhere in that garden so that the plants no longer thrived. Hostas were just about the only plants that did not show stress. Heuchera, lamium, and other shade plants usually somewhat tolerant of dry conditions failed to grow. I do value the shade from this tree – and it’s actually just across the fence on my neighbor’s property, so cutting it down won’t be an option. I have now tried growing boxwood – which seems to grow very slowly – but not die – lemony lace sumbucus – again not thriving but with a little watering is growing slowly, hosta, and various shade plants such as columbine, ferns, tiarella, salmon’s seal and astilbe in over-sized buried plastic pots that have small drainage holes at the bottom. I expect the walnut roots will be slowed down by the barrier and these plants will be better off in pots than having direct competition – I just started the buried pots approach last year, so I will see how that does at preventing root competition. I am also planting up a fair number of large pots to sit on the surface of the ground each year – filled with annuals. Water and mulch helps too. I put in an irrigation system -something usually not required in Upstate NY – Zone 5. This has all been a lot of effort, but I’d rather be sitting in the shade of this mature tree than in the hot blazing sun and proximity to planting is often what makes us enjoy it.

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  5. Hello from New Zealand,
    Thanks for this article and the other awesome information you provide.

    Can you help me with a question please!! I am about to build 3 raised garden beds for vegetable and plant some fruit tree on a property I bought last year.

    I just completed a sun map but it is currently early spring. None of the areas on my property came out in the full sun category.

    Question:
    If on my map some areas have 5 hours sun and there are no tree around, would it be safe to assume in the summer those areas might actually be full sun?

    Thanks for all you do!!

    Reply
    • It depends, where you live. In winter, where you live, the sun should be more overhead than in spring. Provided nothing shades the area, that will give you a longer period of sun, because the sun spends more time above the horizons.

      Look up your local summer sunrise and sun set and compare to the current values.

      Reply
  6. Robert I LOVE THIS! Now I will see how “off the mark I am”! Sketching & judging proportions are a weak area of mine. To compensate, I went clockwise around my garden and took pictures of the beds in sun at 9 AM with my phone. Then I made a spreadsheet and noted the date, time, bed location/name and plants in sun. I’ll repeat this process today at the times you suggest and will use your method to determine the final map areas. You are brilliant!!!

    Reply

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