Sunlight, How much do Plants Need?

In a world full of people, plants are our little green friends. They provide us with food and oxygen while making the planet more beautiful than it would otherwise be! But how much sunlight do they need? And what can we do to ensure that they get the right amount depending on their type?

Why Do Plants Need Sunlight?

Plants are one of the most important organisms on Earth. Without these humble life forms, not only would our planet be devoid of edible fruit and vegetables but oxygen as well! So how do they do it?  It’s a long process where plants capture sunlight to harness their energy through photosynthesis (the process in which plants turn carbon dioxide into sugars). 

Plants then transfer this sugar through cellular reactions that create glucose molecules like cellulose or starch while releasing free oxygen back into the atmosphere. It’s one of the many reasons for having plants in your home. But not all plants need or want the same amount of light to complete this process. So, how do you know how much is the right amount? 

Sunlight Light Quality and Quantity 

Plants are clever little things. They’re able to assess both the quantity and quality of light they receive, which is just one more thing that sets them apart from other organisms on earth. Plants “see” in a way we don’t: plants can absorb only certain types of colour because their pigments work differently than ours do. For example, green isn’t necessary since it’s already present naturally as chlorophyll! Instead, plants need different colours like orange or blue – various combinations affect what type of photosynthesis occurs within the plant’s cells. Altering the light spectrum they receive could make all the difference between two crops by drastically varying nutritional value due to how much energy they capture from sunlight.

For a plant, the quantity of light refers to its intensity. When measuring sunlight, we want to look at the number of photons. Not to get too specific here, but there are two ways we can measure light ones: a super accurate method using PAR Meters or the second with Lux meters. These tools are great if you want to take your plant care to the next level.

The plants know the quality and quantity of light they need to grow successfully. The trick for us is to figure out how we help plants get what they need.

How Are Indoor and Outdoor Light Different?

For a plant, indoor and outdoor light are a little bit different. When a plant is outside, it can absorb light from every direction. Even if the plant is in a partially shaded area, the light reflects off surfaces around the plant. 

When a plant is inside, its light source typically comes from a single direction like a window. When the light only comes at the plant from one direction, angle or source, it reduces the plant’s ability to capture it. 

Types of Light

Now that you understand how a plant uses light to grow, you can consider how much light a plant needs. First, let’s go over the definition of light for plant care.  When you add a plant to your home, the label will tell you how much light is needed based on one of the descriptors below.

Full Sunlight

These plants love full sun, and they like direct light for long, extended periods of it. This type of light happens during the middle of the day hours when the sun is the strongest.  An indoor plant getting full sun will want at least a quarter of the day with the sun hitting the plant leaves. A full sun-loving plant is going to be more heat tolerant and drought tolerant than its counterparts.

Here in Melbourne, we recommend anywhere from 6-8 hours of light a day for your outdoor plants.

Part Sun/Part Shade

A part shade-loving plant will not get direct sunlight on it. It might like the light but often doesn’t want the hot afternoon sun beating on it. Likewise, a part sun-loving plant will need a few hours of good direct light but maybe not a whole day of that kind of light. 

Full Shade

A full shade plant doesn’t like direct sun. This type of plant prefers filtered light. These plants would have evolved under larger tree canopies where light is scarce. So be mindful of where you put this plant.  Typically, you would place them under a verandah with plenty of trees nearby, providing some cover from harsh direct light. For the outdoor garden, Tasmanian ferns are fans of full shade places.  Inside, please don’t put them near a window where there is plenty of sunlight. 

A shade loving plant only needs a few hours of sunlight a day. Often plants that are shade-loving grow well when they have a southern exposure.

Signs Your Plant Is Getting Too Much Light

Most plants are pretty good communicators and will tell you when their growing conditions aren’t quite right. Watch the signs. Plants that are getting too much light will look dried out. Often the edges of the leaves look dried out or burnt. If the plant flowers, the petals will dry out, and the colour will fade from the flowers. If you have a plant with colourful foliage, that colour will fade if there is too much sun.

Very often, a plant getting too much sun looks droopy and may also wilt. 

Signs Your Plant Is Not Getting Enough Light

Your plant might also be trying to tell you it isn’t getting enough. Plants that aren’t getting enough light will look sparse. They often won’t have any new leaf growth. Leaves will be far apart on the stems of the plant.  Plants that are not getting enough light can appear long and thin; often, it will seem as if they are stretching out trying to get as much light as possible. Leaves may even go yellow. 

Sometimes plants that need more sunlight will appear to lean towards their light source. 

Just the Right Amount of Light

We want your plants to look healthy and happy. Here are some ways to see if your plant is well placed and gets just the right amount of light.  Leaves will look lush; this is one of the first signs you have a happy well-lit plant. The leaves should appear green in colour, with dense growth.

If the plant is growing fast, it’s a great sign; it is happy with the amount of light it’s getting. A plant with new growth popping out is probably getting the right amount of light.

Sun Loving Plants

If you have a spot in your home that gets direct bright light for many hours of the day, you might want to check out one of these sun-loving plants.

Indoor Plants: Maidenhair Fern, Ficus Rubra, Ficus Robusta, Fatsia Japonica, Yucca. These varieties will flourish with long hours of direct sunlight in your home. 

Outdoor Plants: Ficus flash, Magnolia, Ornamental trees, Box hedge, Citrus and Fruit trees and Succulents

Shade Loving Plants

Not enough light at home? Don’t worry; some plants love it. Here are some shade-loving varieties.

Indoor Plants: Bird Nest Fern, Blechnum Silver Lady Fern, Devil’s Ivy, Dracaena Fragrans Happy Plant, Ficus Lyrata Fiddle Leaf Fig, Monstera Deliciosa

Outdoor Plants: Hydrangeas, Daphne, Cut Tree Ferns, Helleborus, Acanthus Mollis – oyster Plant

Remember, a shade loving plant still likes light, just not hot direct sunlight. They typically want a few hours of indirect light a day.

Part Shade and Part Sun Loving Plants

Many indoor plants will flourish in this part shade and part sun category. They want some good solid light but perhaps not the direct afternoon beating sun.  Some part shade and part sun plants include-

Indoor Plants: Zanzibar Gem, Strobilanthes Persian Shield, Philodendron Rojo Congo and Hedera Variegated Ivy

Outdoor Plants: Azaleas, Japanese Maples, Camellias, Gardenias and Birds of Paradise

It’s good to know that plants in this category might say they light to be well-lit. Remember, part shade/sun-loving means they like a fair amount of light, just not the direct beating afternoon sun. 

Plants Other Needs Beyond Sunlight

When you are trying to grow a healthy plant, light is only one part of the equation.  If you think your plant lighting is okay, make sure the plant gets its other needs met. Plants will need water; giving them too much or not enough can impact their growth. Plants need good soil. Some plants are particular about the amount of drainage they get. 

Know Which Plants Need Direct Sunlight and Which Prefer Less Light

Knowing how much sun a plant needs is one of the first tricks to becoming a successful plant grower. Whether your plant likes direct sunlight, full shade or something in-between, often it will communicate with you, letting you know if the conditions aren’t quite right. Check out our online plants to shop online for plants that we will happily get delivered to your home. Choose a nicely lit spot in your home and add a plant to it today.