Every plant tag at the garden center tells you the same thing: how much sun the plant needs. “Full Sun.” “Partial Shade.” “Full Shade.” Simple enough, right?
Except new gardeners consistently get this wrong. They plant sun-loving tomatoes in spots that get “plenty of light” but produce disappointing harvests. They put shade plants in afternoon sun and watch them scorch. They assume their bright, south-facing location is perfect for everything, then wonder why half their plants struggle.
The problem isn’t the labels, it’s that nobody explains what these terms actually mean in real-world conditions. Let’s fix that.
What “Full Sun” Actually Means
Full sun means six to eight hours of direct, unobstructed sunlight per day. Not filtered through tree branches. Not reflected off a wall. Direct sunlight hitting the plant.
The key word is “direct.” That bright spot under your maple tree? Not full sun, even though it feels light and airy. The area next to your fence that gets morning sun but is shaded by 2pm? Not full sun. The spot that gets great light but it’s filtered through a patio cover? Still not full sun.
When to count the hours: The sun from 10am to 4pm is strongest and counts the most. Early morning sun (before 9am) and late evening sun (after 6pm) are weaker. A plant that gets sun from 7am to 1pm might technically get six hours, but it’s not the same as six hours spanning the middle of the day.
What full sun looks like in your yard: No shadows from trees, buildings, or structures during peak hours. If you stand in that spot at noon on a clear day and you’re not in anyone’s shadow, you’re probably in full sun. Check again at 2pm and 4pm to be sure.
Plants that need full sun: Most vegetables (tomatoes, peppers, squash, cucumbers, beans), many herbs (basil, rosemary, oregano), sun-loving flowers (zinnias, marigolds, sunflowers, coneflowers), and fruit-bearing plants. These plants can tolerate less sun, but they won’t produce as well. A tomato plant in five hours of sun will give you tomatoes, just fewer of them, and the plant will be more prone to disease.
What “Partial Sun” and “Partial Shade” Mean (Yes, They’re Different)
Here’s where it gets confusing: partial sun and partial shade both mean roughly 3-6 hours of sunlight per day, but they have different connotations.
Partial Sun: Usually means the plant prefers more sun than shade, closer to that 5-6 hour range. It can handle less, but it performs better with more. Morning sun with afternoon shade often works well. Think of these as sun-lovers that can tolerate some shade.
Partial Shade: Usually means the plant prefers more shade than sun, closer to that 3-4 hour range. It can handle some direct sun, but too much and it’ll struggle. These are shade-lovers that can tolerate some sun exposure.
The distinction matters less than understanding the 3-6 hour range and knowing whether your plant leans toward the sun-loving or shade-loving side of that spectrum.
What partial sun/shade looks like in your yard: Morning sun that gives way to afternoon shade. A spot under a tree with a light canopy that allows dappled sunlight through. An area that gets direct sun for part of the day but is blocked by a structure or tree for the rest.
Plants that need partial sun: Many leafy greens (lettuce, spinach, arugula), herbs like cilantro and parsley, root vegetables (beets, carrots, radishes), and flowers like impatiens, begonias, and astilbe. These plants often appreciate some shade, especially in hot climates where afternoon sun can stress them.
What “Full Shade” Actually Means
Full shade doesn’t mean total darkness. It means less than three hours of direct sunlight per day, or filtered/dappled light throughout the day without direct sun exposure.
The confusion: Many new gardeners hear “full shade” and think “that dark corner where nothing grows.” But full shade locations still get light, just not direct sunlight. Under a dense tree canopy, on the north side of a building, or in a courtyard surrounded by tall structures.
What full shade looks like in your yard: That area under your deck where light filters through the boards. The space on the north side of your house. Under mature trees with thick canopies. These spots are bright enough to read a book comfortably, but the sun never directly hits them.
Plants that need full shade: Hostas, ferns, astilbe, heuchera, lamium, and many woodland plants. These plants evolved under forest canopies where direct sun rarely penetrates. Put them in full sun and their leaves will burn, bleach out, or develop brown crispy edges.
The Biggest Sun Mistakes New Gardeners Make
Mistake 1: Overestimating Available Sun
This is the most common error. Your brain sees a bright, pleasant spot and assumes it’s sunny enough for tomatoes. But when you actually track the sun throughout the day, you discover it only gets four hours of direct light.
How to avoid this: Do the sun audit. Pick one clear day and check your garden spot every two hours from morning to evening. Take notes. Be honest about what you find. Your tomatoes won’t care about your intentions, they’ll respond to the actual sunlight available.
Mistake 2: Not Accounting for Seasonal Changes
The sun’s path changes throughout the year. That spot that gets eight hours of sun in June might only get five in April or September because the sun is lower in the sky and neighboring trees or structures cast longer shadows.
How to avoid this: If possible, observe your space across seasons before committing. If you can’t wait, know that spring and fall sun patterns differ from summer, and adjust expectations accordingly. Early spring greens might thrive in a spot that becomes too shady once trees leaf out.
Mistake 3: Ignoring Afternoon Sun Intensity
Six hours of morning sun is not the same as six hours of afternoon sun, especially in hot climates. Afternoon sun from 2pm-7pm is more intense and stressful for plants than morning sun from 7am-1pm, even though both provide six hours.
How to avoid this: When reading plant tags that say “partial shade,” understand that often means “protect from intense afternoon sun.” Morning sun with afternoon shade is the ideal partial shade situation for most plants. Afternoon sun with morning shade is harsher.
Mistake 4: Trusting “Seems Bright Enough”
Human eyes are terrible judges of plant-usable light. A covered patio might feel bright and cheerful to you but still not provide enough direct sun for vegetables. Conversely, a spot that seems dim to you might be perfect for shade plants.
How to avoid this: Don’t trust your feelings. Count the actual hours of direct sun. Take photos of the space at different times of day if it helps you track shadows and sun exposure patterns.
How Sun Requirements Change By Climate
Here’s something most plant tags don’t tell you: sun requirements can shift based on where you live.
In hot climates (Zones 8-10): Plants that typically need “full sun” often appreciate some afternoon shade during the hottest months. That tomato plant that thrives in eight hours of sun in Michigan might prefer six hours with afternoon shade in Arizona. The intensity matters as much as the duration.
In cool climates (Zones 3-5): Plants often need all the sun they can get. Those “partial shade” recommendations are based on average conditions. In cooler regions with less intense sun, many partial shade plants perform beautifully in full sun because the light isn’t as harsh.
The lesson: Use plant tags as a starting point, but observe how plants actually perform in your specific conditions. If your full-sun tomatoes look stressed and sunscalded, try giving them some afternoon shade. If your partial-shade lettuce is stretching and looking weak, it might need more sun in your climate.
Matching Plants to Your Actual Conditions
Stop trying to change your conditions to match the plants you want. Start choosing plants that match your actual conditions.
If you only have 3-4 hours of sun: Embrace it. Grow lettuce, spinach, kale, herbs like cilantro and parsley, and shade-loving flowers. Stop trying to make tomatoes work, they won’t give you the harvest you’re hoping for, and you’ll just end up frustrated.
If you have blazing afternoon sun in a hot climate: Choose heat-tolerant varieties. Grow sun-lovers but give them afternoon shade if possible. Mulch heavily to keep roots cool. Accept that some plants that “need full sun” in catalogs might actually prefer a break from your intense conditions.
If you have perfect full sun: You won’t need to compromise. Grow whatever you want, tomatoes, peppers, squash, most flowers. Just make sure you’re prepared for the watering demands that come with full sun exposure.
If your whole yard is shaded: Container gardening might be your answer. Move containers to follow the sun throughout the day, or focus exclusively on shade plants and stop fighting your conditions.
The Simple Sun Assessment You Need to Do
Before you plant anything:
- Pick your spot
- Choose a clear, sunny day
- Check every 2 hours from 8am to 6pm
- Note when direct sun hits the spot
- Add up the hours
- Be honest about obstructions (trees, buildings, fences)
Write down your findings. This is your actual sun situation, not what you wish it was. Now match plants to those real conditions.
If you have six hours or more of direct sun, you can grow full-sun plants. If you have 3-5 hours, stick with partial sun/shade plants. If you have less than three hours, embrace shade gardening.
Conclusion
Sun requirements aren’t complicated once you stop guessing and start measuring. The difference between a thriving garden and a disappointing one often comes down to this single factor: matching plants to the light conditions you actually have, not the ones you wish you had.
Stop trusting “seems sunny enough.” Stop assuming that bright spot is full sun. Spend one day tracking the sun across your space, count the hours honestly, and then choose plants accordingly. Your garden will reward you with better growth, fewer problems, and far less frustration.
Key Takeaways
- Full sun = 6-8 hours of direct sunlight, not just bright light
- Partial sun/shade = 3-6 hours, with partial sun leaning toward more sun and partial shade toward more shade
- Full shade = less than 3 hours, or dappled light all day with no direct sun
- Track your sun for one full day before making plant decisions, your eyes will deceive you
- Morning sun is gentler than afternoon sun, especially in hot climates
- Match plants to your actual conditions instead of trying to force plants into spaces they’ll never thrive in
- When in doubt, observe first, plant second, a season of watching your space will teach you more than guessing ever will
Need more help planning your garden? Check out our guide on soil basics, or learn how to choose your first plants based on your specific conditions.
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