Full Shade Definition
How Much Shade is Full Shade for Plants?
Learn what the exact definition of full shade is, and how to measure full shade in your landscape.
Whether you’re just starting out with gardening or trying to choose plants for a new project, you’ll often come across the term full shade. But what does it really mean? Understanding the exact definition of full shade is crucial for giving your plants the best chance to thrive. Let’s break it down and shed some light 😉 on how much shade is full shade for plants, and what this term really means for your garden.
Full Shade Definition
Full shade is defined as 3 or less hours of sunlight per day, including direct sunlight, filtered sunlight, dappled shade, and indirect sunlight. Let’s define these different types of light:
Direct sunlight: An intense, uninterrupted path of sunlight traveling directly from the sun to the plant, without any obstructions or filters. Example: sunlight shines directly on the leaves of a hosta for 3 hours every morning until the light gets blocked by the neighbor’s shed.
Filtered sunlight / Dappled shade: These two terms are used interchangeably, with both referring to the soft rays of light formed when the sun’s beams pass through a barrier like a tree canopy or pergola. This creates brief, sporadic and less intense bursts of sunlight throughout the day. Example: sunlight filters through the branches of a tall, mature tulip poplar tree and intermittently shines on the azaleas and rhododendrons planted underneath.
Indirect sunlight: Indirect sunlight for outdoor plants is light that does not travel directly from the sun to the plant, but instead is diffused or reflected off nearby surfaces like walls, fences, sidewalks, or driveways. Example: Sunlight bounces off a concrete sidewalk and gets reflected on to the pots and planters placed underneath an awning.
It’s easy to assume that an area of your garden has full shade, especially if it seems dark. However, sunlight can be deceptive, with amounts varying throughout the day and across the seasons. To ensure your plants thrive, it's essential to measure the actual amount of sunlight hitting the landscape. Keep reading to learn how simple it is to assess your garden's light conditions.
How to Measure Full Shade
Measuring full shade isn’t as complicated as it might sound. You don’t need any fancy equipment, just a bit of time and attention. Keep in mind that certain areas may be brighter in late fall and winter when the trees are bare of leaves, and plants may receive more sunlight during the extended daylight hours of the late spring and summer months.
Here’s a simple way to measure:
Pick a spot: Choose the area in your garden, yard, deck, or balcony where you want to measure the amount of sunlight and shade. You can use sticks or garden stakes to mark the area, if desired.
Observe the sunlight: Check how much sunlight the spot gets throughout the day (this includes direct sunlight, filtered sunlight, dappled shade, and indirect sunlight - see above for definitions). Start measuring from when the sun rises in the morning, and take note of what time the area gets sunlight and what time it becomes shaded.
Track the hours: Tally up how many hours the spot receives sunlight. If it adds up to more than 3, you have a full sun or part shade spot. If it totals less than 3 hours (the definition of full shade for plants), you’ve got yourself a full shade spot!
Devices like sunlight meters aren't necessary, and can even be inaccurate due to factors like weather conditions and nearby reflective surfaces. If you want to use tech to help you visualize where and when the sun will hit specific areas of the garden, the Sun Seeker app can be helpful (and fun to play around with!).
But really, you don’t need anything fancy to measure light levels. By simply observing your garden over the course of a day, you will gain a better understanding of the unique light conditions in your landscape.
Full Shade vs Deep Shade
So, what’s the difference between full shade and deep shade?
Full Shade: 3 or less hours of direct sunlight per day.
Deep Shade: Almost no sunlight.
Full shade means an area gets 3 or less hours of sunlight per day, perfect for plants like astilbe.
Deep shade is a type of full shade. Deeply shaded areas receive no direct sunlight and very little indirect sunlight, like the area underneath a tall deck.
It can be challenging to find plants that grow in deep shade, but they do exist! Liriope, ferns, hostas, and hellebores are good examples of plants that tolerate deep shade.
Knowing the difference between full shade and deep shade will help you to pick plants that can truly flourish in your garden!
Can I Grow a Part Shade Plant in Full Shade?
Part shade plants may be able to survive for a time in full shade conditions, but they won’t thrive and will eventually decline in health. When part shade plants don’t get their required 3-6 hours of daily sunlight, they exhibit signs indicating they’re struggling:
Leggy Growth: When they don’t receive enough light, part shade plants begin to stretch towards a light source, resulting in tall, thin stems with large spaces in between the leaves. This is referred to as “legginess” and can make the plant look sparse and weak.
Reduced Flowering: Flowering part shade plants rely on sunlight to produce their flowers. In full shade, plants will flower less because they lack the energy needed for flower production.
Slow or Stunted Growth: Part shade plants will grow slowly and may even stop growing altogether if they don’t receive enough light. This can affect their overall health and appearance, and they will also become more susceptible to diseases and insect pests.
Paler Leaves: Insufficient sunlight can lead to less vibrant foliage and pale leaves.
If you have full shade, don’t waste your time and money on plants that require part shade - choose a full shade loving plant instead!