What Does “Full Sun” In Gardening Mean?
What does it mean, full sun, part sun, part shade, full shade? And how do you know what’s in your garden? Let’s look at light levels to ensure you choose the right plants for your containers and landscape. Sunlight is the essential element for all plants to survive, so it’s critical to understand it thoroughly.
So, let’s talk about sunlight—what exactly do the terms “full sun,” “part sun,” “part shade,” and “full shade” mean? And how do you know what type of sun you have in your garden? Light levels are defined the same way for all plants, whether you’re shopping for annuals, perennials, or shrubs. Begin with the fundamental definitions.
Definitions of Basic Light Levels
Full sun – 6 hours or more of direct sun per day.
Part sun – 4 to 6 hours of direct sun per day, including some afternoon sun.
Part shade – 4 to 6 hours of direct sun per day, preferably before midday.
Full shade – less than 4 hours per day of direct sun.
How Do You Determine How Much Sun You Have?
You could use a garden light meter to determine how much sun the spot you want to plant in receives each day. By simply observing your garden for a few days during the summer, you could save that money to spend on more plants. Locate the spot where you want to plant, then record on a piece of paper whether or not that spot receives direct sunlight at each hour of the day. Do this for a few days to get a feel for the average.
What exactly is Full Sun?
Six or more hours of direct sun per day is considered full sun. If you live in a newly built development or a rural area with few trees, your garden may receive no shade at all during the day. Perhaps your front porch faces south and has nothing in the way of the sun from midmorning to early evening. Full sun is defined as any amount of time in the sun that exceeds or equals six hours.
What exactly is Part Sun?
Four to six hours of direct sun per day is considered part sun. Not all of those hours have to be consecutive; it could be a few hours of morning sun followed by a few more in the afternoon. Although a plant that prefers part sun does not need to be in direct sun all day, it will grow and bloom best if at least some of those hours are in the afternoon. Heat and intense sun exposure are required for these plants to produce flowers and new growth.
What exactly is Part Shade?
Part shade is also defined as four to six hours of direct sun per day, with most of that time spent in the morning when the sun’s rays are less intense. Plants that prefer part shade benefit from “cool sun,” which means direct sun in the morning or evening and protection from the hot midday sun.
What exactly is Full Shade?
Less than four hours of direct sun per day is considered full shade. We didn’t say zero hours of direct sunlight because that would be dense shade, the darkest of all light levels where few plants can survive. Complete shade plants benefit from a few hours of sun each day, preferably in the morning.
Understanding Plant Label Light Levels
When shopping for or researching plants, consider how much sun they require. Because this information is so critical, it is always included on plant labels. Here are a few examples of what you might find and how to interpret it.
What the Label Suggests “Full Sun”?
When the only light level listed for a plant is full sun, it will require at least six hours of direct sunlight to grow and bloom. If you plant it in low-light conditions, it will most likely not bloom, and in some cases, the plant will die. Full sun plants are frequently heat tolerant, and some can tolerate drier soils. Choose full-sun plants for your garden’s brightest spots.
When does it say Part Sun to Sun on the label?
When a plant is listed as the part sun to sun, it will grow and bloom in both part sun and full sun conditions, requiring at least four hours of direct sunlight. Because part sun implies that the plant requires some heat and intense sun to produce flowers, you should select a spot where at least some of those hours are in the direct midday sun. Most part-sun to full-sun plants will bloom more profusely in full sun and produce fewer flowers in part sun.
What does the label say Part Shade to Shade?
When a plant is listed as part shade to shade, it prefers to grow in less than six hours of direct sunlight per day, most of that time spent in the less intense morning sun. These plants thrive in cooler climates with plenty of moisture, and they can easily scorch in the hot afternoon sun. Some part shade to shade plants produce flowers, but many are grown for their decorative foliage rather than for their flowers.
What it say “Sun” or “shade” on the label?
When a plant is listed as sun or shade, it will grow in any amount of sunlight in most parts of the country. Some plants are very adaptable in terms of how much sun they require to grow and thrive in direct sun and shade. ColorBlaze® coleus, for example, was bred to withstand the hot Florida sun but also grows well in the shade of Michigan. The color of the foliage and the number of flowers may vary slightly depending on the light level, but these plants are stunning wherever they are grown.
Regional Differences in Sun and Shade Requirements
When considering only the number of hours of direct sun that plants receive, the definitions of sun and shade appear relatively straightforward. Because those climates are relatively temperate. The number of hours of sunlight is an excellent general guideline to follow if you live in the Midwest, Upper Midwest, Northwest, or on the East Coast.
If you live in a warmer climate, such as the West, Southwest, or Southeast, you must also consider the sun’s intensity. The sun’s rays are more intense and hotter in those areas because they are closer to the equator. As a result, some sun-loving plants will need to be protected from the midday sun to avoid scorching, and they may also need to be watered more frequently.
A good example is bigleaf hydrangeas (Hydrangea macrophylla). Bigleaf hydrangeas thrive in full sun and average to moist soil in the North. However, when grown in the South, the same plants require protection from the hot afternoon sun and must be watered more frequently to prevent wilting and leaf scorch. If you garden in the South and a plant label says part sun to full sun, it’s a safe bet that it will grow with some afternoon shade.
Many Plants Are Versatile
Many plants’ sunlight requirements will include phrases like “Full Sun to Partial Shade” or “Partial Shade to Full Shade.” This indicates that the plant will do well in various sunlight exposures, giving you more flexibility in deciding where to plant it.
However, keep in mind that many of these plants still grow a certain amount of sunlight to thrive. While plant tags or seed packets may indicate that a plant is suitable for any location, further research into the species may reveal that the plant thrives in a specific sunlight exposure but tolerates other conditions. It is always best to research to learn about specific nuances and the preferred growing environment of any plant you are thinking about planting.
Finally, the only accurate indicator is how well your plants are growing. If the foliage is scorched or burned or the flowers are lanky and leaning in search of sunlight, the plant is most likely not in the best spot. Don’t be afraid to dig up and relocate plants in your garden if you believe they are not in the proper location. The majority of species can be successfully transplanted. If possible, do so on a cloudy day, and remember to water thoroughly in its new location until it has established itself.
Making a Sunshine Map
Knowing where the sun and shade are on your property can help you decide what to plant. Sunseeker and Sunnytrack, for example, can show you the solar path on any given day of the year. However, they do not show you obstacles that can create shade, such as neighboring buildings or trees.
A sunshine map is simple to create. All you need is a full day at home, a piece of paper, a pencil, and a clear day.
Make a chart on one side of the paper that lists your garden areas. Write the hours of the day across the top in 2-hour increments, beginning at 6:00 AM and ending at 8:00 PM.
Begin early in the morning, shortly after dawn, and continue until late in the evening. Step outside every 2 hours to inspect your gardens and note whether they are in the sun or shade.
Count the number of times you wrote “sun” for each spot at the end of the day. If it’s more than 6, you’ve got a full sun garden! Between 6 and 4 hours indicates a part-sun/part-shade area, and less than 4 hours indicates a shady spot.
Some gardeners will take photos, others will draw a map, and still, others will record the data in an Excel spreadsheet. You must do what is best for you. Plants are forgiving, so it doesn’t have to be complicated or exact.
It’s ideal if you can do this on the first day of summer, but it can be done any time a few weeks before or after. Consider recording your sunshine levels every few months throughout the year.
If you cannot stay at home all day, there are light meters and other tools available for purchase that will do the tracking for you. Alternatively, perhaps a fellow gardener has one you can borrow.
Revisit your map every couple of years – trees and hedges grow, fences are built, neighbors add on. There are a variety of factors that affect your light exposure over time.
How Do You Calculate Full Sun?
Full sun means that your plant receives at least six hours of direct sunlight per day. If you want a convenient way to measure this, a sunlight meter for the garden is a good option.
This three-way meter detects moisture, light, and pH. Change the settings to get the reading you want.
Direct Sun vs. Full Sun
Except for time, there is no distinction between these two terms in gardening. Full sun is defined as six hours or more of direct, unfiltered sunlight required by your plant. The ability of the sun to reach your plant without interference from other plants or shadows shading it is referred to as direct sun.
Is It Better For Plants To Get Their Sun In The Morning Or The Afternoon?
Each plant has a preference for morning or afternoon sun. The morning sun, though it can be harsh, is more relaxed. The afternoon sun can be scorching on a plant. Most plants prefer direct morning sun to direct afternoon sun, though some plants, such as tomatoes, which require at least 8 hours of sunlight, prefer the afternoon sun.
Is Afternoon Sun Considered Full Sun?
Full sun can appear in the morning or afternoon. If your plant requires partial sun, you may be able to get away with six hours of morning sunlight because it isn’t as intense as afternoon sunlight. If your non-shaded plant spends six hours in the afternoon sun, it receives full sun. If your flowers, such as annuals and vegetables, are in the direct afternoon sunlight, you’ll need to check their water levels regularly.
Is Full Sun Considered To Be East-Facing?
Because the sun rises in the east, your plants get morning sun on that side of your house. The east side of your home may not be the best choice for full-sun gardening, depending on where the sun moves once it’s up, if you have tall shading trees or the shadow configuration of your home.
Keep an eye on the sun’s movement and how long it stays in your proposed full sun location to determine if your east-facing side is best for full sun plants.
This resin compass sculpture for your garden will keep you from forgetting which way is east.
Can Full Sun Plants Survive In Shade?
Your full-sun plants might survive in the shade, but they won’t thrive. Without enough sunlight, flowering plants will bloom less or not at all. The same is full for vegetables that require direct sun. Your yields will be lower if you plant in the shade.
Other signs of trouble include stretched or leggy stems, yellowed leaves, and slow growth. All of these symptoms indicate that your plant is not getting enough sun.
Can a Garden Get Too Much Sun?
It most certainly can. If you notice your plants’ leaves turning brown on the edges due to leaf scorch, it’s an indication that they’re getting too much sun. This is something that can happen in the middle of summer. Consider using a garden shade or umbrella during the hottest months to alleviate this problem. Potted and container plants should be moved to a more shady location.
A shade cloth, such as this one, is an excellent temporary solution for shielding your plants from the hottest part of the day.
Where Does the Most Sun Shine in My Yard?
This is unique to each individual’s yard. You want to find a spot not obstructed by trees or your house. South and west-facing garden areas in the Northern Hemisphere are likely to receive more sun unless obstructed by a building or tall trees.
The best test is spending a day observing how the sun moves across your property. It varies slightly with the seasons, but you have firsthand knowledge.