Plant tags say “full sun” or “part shade” as if everyone knows what their yard gets. Most people guess, and the guess is usually generous. A spot that feels sunny at lunch can sit in a fence shadow from 3 p.m. on.

Whole-yard sun charts don’t help much either, because sun changes over a few feet. The tomato by the fence and the one 4 feet out can get very different days. So measure light where each plant will actually sit. Then let those notes decide what you buy, where it goes and how often you water it.

Before buying plants, collect three things: a rough sketch of the area with measurements, the position of anything tall nearby (house, fence, trees, a neighbor’s garage), and one full clear day of sun notes.

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12 practical moves for a garden sunlight map

1. Map the watering path along with the sun

While you walk out to log the sun each hour, note how far each sunny spot sits from the tap. The sunniest corner of the yard is often the one farthest from the house, and a full-sun bed dries out fastest.

Full-sun beds in summer often need water every 2 to 3 days, and pots every day. If your best spot is more than about 50 feet from a hose, a slightly shadier spot near the tap may give better plants overall.

2. Buy only the tools the map needs

A sunlight map needs a tape measure, a notebook or graph paper, a pencil and some markers to stake each spot. Weatherproof plant labels or 12 inch wooden stakes work well as markers. A phone alarm for each check keeps you honest.

Honestly, skip the light meters and sun-tracking gadgets. Hold your hand over the spot: a crisp shadow means direct sun.

3. Set a check-in schedule for mapping day

Pick one clear day and check every hour from 8 a.m. to 6 p.m., or every 2 hours if that is all you can manage. Each visit takes 2 to 3 minutes: look at each stake and write S for sun, P for patchy and D for shade.

Those letters end up shaping your care schedule too. A spot with 8 hours of sun usually needs more watering visits than one with 4.

4. Mark mature spacing before planting

A plant’s sun changes as its neighbors grow. A tomato reaches 4 to 5 feet by midsummer and can shade anything within 1 to 2 feet on its north side. Mark mature widths with the tape so tall plants sit north of short ones.

The garden plant spacing guide for beginners lists typical widths, which helps you predict the shade your own plants will cast in July.

5. Put soil money in the sunniest spots first

Once the map shows where the 6 to 8 hour spots are, spend your compost there. Tomatoes and zinnias will use the richer soil. A shaded corner of ferns gets by on much less.

Skip decorative edging or new pavers until the map says where plants will go. Build first and map later, and you can easily end up with a vegetable patch in 3 hours of sun.

6. Plan a seasonal reset around the light

The sun moves through the year. Near the June solstice the sun is at its highest and shadows are shortest; in early spring and fall it sits lower and shadows stretch. At around 40°N latitude, a 6 foot fence shades about 2 feet of ground at midday in summer but about 5 feet in early spring.

That means a bed that is full sun in July can be part shade at planting time. Map once around your last spring frost, when you sow, and once in early summer, then plan cool-season crops for the spots that only light up later.

7. Revise the map after real weather

Your first map comes from a single day. After 3 or 4 weeks of real weather, check what the plants say: leaves that wilt every afternoon in a “part sun” spot mean that spot gets hotter afternoon sun than you logged.

Afternoon sun from about 1 to 5 p.m. is hotter than morning sun, so 4 hours after lunch can stress a shade plant more than 6 hours in the morning. Add a note next to each spot: morning, midday or afternoon.

8. Keep labels through establishment

Leave the mapping stakes in and add the plant name and the hours of sun to each label, like “chard, 5 hours, morning.” Keep them through the first 6 to 8 weeks.

When a plant struggles, the label tells you straight away whether light could be the reason. A pepper labeled “4 hours” that never flowers has its answer written on the stick.

9. Judge progress by new growth

Too little light shows in the newest growth: long, thin stems with wide gaps between leaves, plants leaning hard toward one side, and few or no flowers. Too much sun shows as bleached or crispy patches on the leaves facing the afternoon.

Give a new plant 2 to 3 weeks to settle before judging. If stretching or scorch keeps showing on new leaves after that, the spot is wrong for the plant, and moving it beats feeding it.

10. Ask local help before cutting for light

It is tempting to fix a shady spot by cutting. Bypass snips handle shrub twigs up to about half an inch thick, which is enough to thin a hedge that shades a bed. Anything bigger is a different job.

For tree limbs above head height, near power lines, or on a tree that isn’t yours, call a certified arborist, and check local rules before removing a whole tree. Thinning a canopy usually costs less than removal and often adds 1 to 2 hours of filtered light.

11. End the first season with useful notes

Before the first fall frost, write one line per spot: hours of sun, what grew there and how it did. Now the map rests on a whole season, not one day.

Notes like “basil, 7 hours, great” and “lettuce, 7 hours, bolted by week 6” tell you more about a spot than any plant tag.

12. Define one useful outcome for the map

Give the map one job. “Find the best 4 by 8 foot spot for tomatoes” is a good outcome; “understand the whole yard” is too big for a first try.

No spot reaches 6 hours? That’s still an answer. Plan around greens, herbs and shade flowers, and stop buying sun crops.

Define a realistic first-season goal for a garden sunlight map

A realistic goal is one mapped bed or three to five mapped spots, with one plant choice made for each. That fits a single Saturday and leads straight to buying the right plants.

The University of Maryland Extension landscape planning resource puts site study before plant choice, and sun and shade patterns are a big part of it. For a small garden that boils down to one page, a sun, soil and routine starter map, filled in before you plant.

Field	What to record for each spot
Spot	A name or number and its distance from a fixed point, like the back step
Morning sun	Hours of direct sun before about noon
Afternoon sun	Hours of direct sun after about noon
Total and category	6 or more is full sun, 3 to 6 is part sun or part shade, under 3 is shade
Soil	Dry, damp or soggy a day after rain, and how easily a trowel goes in
Routine	Distance to water and how often you will pass by
Plant choice	One plant or group that fits all of the above

Here’s how a filled-in row might look. Spot 1, 6 feet from the back step, gets 3 hours morning and 4 hours afternoon sun, drains well and sits 10 feet from the tap. That is 7 hours of full sun, close to water, so it becomes the tomato and pepper bed. Spot 2, along the north fence, gets 2 morning hours only: shade, so hostas and ferns.

Match the map to local light, soil and timing

Use the hours to sort plants into three groups:

• 6 to 8 or more hours: tomatoes, peppers, squash, beans, zinnias, lavender and most herbs grown for flavor.
• 3 to 6 hours: lettuce, spinach, chard, kale, parsley, mint, astilbe and many coral bells.
• Under 3 hours: hostas, ferns, impatiens and coleus; few vegetables do well here.

Shade changes soil too. Shady spots dry slowly, often stay cool into late spring, and sit under tree roots that compete for water. Add a soil note for each spot so you don’t put a thirsty crop into a bed where tree roots take the water first. If your sunniest spot is lawn, a no-dig vegetable garden for beginners lets you plant there without lifting the turf.

Timing ties back to frost dates. In spring, deciduous trees are still bare around your last frost, so a spot can look sunny when you plant and turn shady 3 to 5 weeks later once leaves fill in. Map again after the trees leaf out before you trust the numbers for summer crops.

Build a weekly care routine that fits real life

Let the map set the order of your care visits. Start with the sunniest spots, since they dry first, and leave shady ones for last. In hot weather, full-sun beds often need deep watering 2 or 3 times a week; shade beds may need it once.

A heat wave above 90°F is where a sunlight map gets tested. Walk the garden at about 4 p.m. on the first hot day and note which plants droop. Those are the spots where afternoon sun is too much for what you planted, and next year they get a tougher plant or some afternoon shade from a taller neighbor.

• Twice a week (15 minutes): water full-sun spots, check soil 2 inches down in part-sun spots.
• Once a week (30 minutes): weed, check new growth for stretching or scorch, jot one line per spot.
• Once a month: stand in each spot at about 3 p.m. and confirm it still gets the sun you logged.

Review the first season before expanding

In fall, compare the starter map with what actually grew. If most plants matched their spot, the map works and you can expand using it. If several underperformed, map again on a clear day the following spring before adding anything new.

Expand into the next-best spot on the map, not the most convenient one. A 7 hour spot 30 feet away usually beats a 4 hour spot by the door for vegetables. If you are ready to turn your best spot into a food bed, the first small vegetable garden plan picks up from there.

Keep the map and redo it every 2 or 3 years. Trees grow, neighbors build sheds and fences change, and a spot that gave 7 hours can drop to 5 without you noticing.

FAQ

What should I know before planning a garden sunlight map?

Know which spots you might plant and what tall objects sit nearby. Choose a clear day and plan to check every 1 to 2 hours from about 8 a.m. to 6 p.m. Mapping after trees leaf out gives the most honest summer numbers.

How much space does a garden sunlight map need?

Map only the area you might plant, even a single 4 by 8 foot bed or a few pots on a patio. Within a bed, mark spots about every 2 to 4 feet, since light can change that quickly near fences and walls. A whole-yard map is useful later but not needed to start.

What is the simplest way to start a garden sunlight map?

Push three to five stakes where you might plant, set an hourly phone alarm, and write S or D next to each stake number at every check. Count the S marks at the end of the day: that is your hours of direct sun. The whole thing takes about 30 minutes of actual work spread across one day.

What common mistakes should I avoid with a garden sunlight map?

The usual ones: mapping on a cloudy day, mapping before trees leaf out, and checking only at noon. Treating morning and afternoon sun as the same thing is a close fourth. Log both and re-check after a heat wave.

How do I maintain a garden sunlight map over time?

Add one line per spot each fall about how plants did, and re-map fully every 2 to 3 years or after anything tall changes nearby. If a plant that used to thrive starts stretching or stops flowering, re-check that spot first before changing feed or water.

When should I get local or expert advice about a garden sunlight map?

Ask for help before removing or heavily cutting a tree to gain light; that calls for a certified arborist and sometimes a permit. Your county extension office can also suggest plants for 3 to 6 hour spots in your zone. Bring your map and your last frost date.

Final thoughts

A garden sunlight map takes one day and saves a season of guessing. Once you know which spots get 7 hours and which get 3, picking plants gets much easier, and a lot of leggy, flowerless plants suddenly make sense.

Check the forecast for the next clear day, push in three stakes where you hope to plant, and set an alarm for every hour from 8 a.m. to 6 p.m.

Last update on 2026-10-01 / Affiliate links / Images from Amazon Product Advertising API