Hello, plant enthusiasts! We are all aware that plants need sunshine to live. You have heard it everywhere since you were a little kid, and some of us even completed clever little projects in school to demonstrate it. Most of us can recall the fundamentals of how a plant lives and why it need sunlight to do so. However, is this true? Can plants survive in the absence of sunlight?
The simple answer is yes; it is possible to grow a plant in the absence of sunshine. There are only two methods for a plant to develop in the absence of sunlight:
- Substituting artificial light for natural light to nourish your plant.
- It may be a parasitic plant that is not photosynthesis-dependent.
A little-known truth is that plants that are green need sunshine or artificial light to live and thrive.
While we often connect the light that plants need for survival with the sun, this is not always the case. It is not that straightforward either, therefore let us go further into this topic.
Section Table of Contents
Why do plants need sunshine and how do they become green?
Photosynthesis. If there is one term that unifies all non-plant humans, it is photosynthesis. We have all heard it, studied it, and discussed it, but what is the big deal?
That is, it is the enchanted mechanism by which your home plants consume food. It is so amazing because plants are autotrophs, which is a fancy term for preparing their own food from scratch before consuming it.
What is photosynthesis and why is sunlight required?
Plants absorb carbon dioxide from the air, water from their roots, and utilize light as a fuel source to make glucose, or sugar, and also produce that stuff we all adore called oxygen as waste. That is one of the primary reasons why plants are not just essential for existence, but crucial for survival.
As a result, we all inhale plant excrement.
However, it becomes much more intriguing. Have you ever heard that sunshine is comprised of a variety of colors?
Plants, on the other hand, have a chemical called chlorophyll. Chlorophyll is responsible for light absorption. To put it another way, chlorophyll absorbs red and blue light and reflects back green light.
Does this sound familiar?
That is precisely why plants are green; their light-absorbing molecule reflects the color green.
Thus, the magical rule here is that if the plant is green, it need light to live and nourish itself. This whole process takes place in the leaves, which are also the only portion of the plant that remain green throughout the year. Flowers are seldom green, which indicates that they lack chlorophyll and therefore serve another function.
I am sure you have observed how leaves are flat yet broad. They are often shaped like plates, since the greater surface area they have, the more sunlight they can absorb.
Additionally, they contain tiny veins that carry water and minerals.
Apart from the fact that the whole process is self-contained and unrelated to anything else, the great thing about photosynthesis is that the waste product is oxygen. Thus, the stuff that we breathe and that is necessary for you and me to exist is plant feces.
Additionally, plants engage in cellular respiration, which is the mechanism by which they take in oxygen. This is how the idea that plants may kill you at night was born.
And now that you know why I am fascinated with plants, how could you not be?
How long can a plant remain dormant in the absence of sunlight?
For this one, we are going to disregard artificial light and focus only on natural light sources, particularly sunshine. There will be no fire, torches, or anything else that might set your home on fire.
But first, let us discuss what sunshine really is. When I am asked how much sunshine a plant need, I am often asked how much direct sunlight it requires.
Instantaneously, the mind is drawn to a beam of sunshine streaming through the window. However, just because a plant is not in direct sunlight does not imply it is not receiving any sunlight.
Let us conduct a thought experiment in which you relocate your plant from the window to a dark area of your room. You will still see the plant, which indicates that photons are bouncing about the room and hitting your eye, but also striking the plant, which is why you can see it.
The plant still utilizes this light source; it is not as abundant as direct sunshine, but it is still a light source, and plants are very adept at using any light source.
How well a plant utilizes light sources really relies on the species and the need for it; as we all know, there are hundreds of thousands of kinds of plants from all over the globe.
Certain plants thrive in deserts or places with 12 hours of direct sunshine, and as such, they are very reliant on receiving as much direct sunlight as possible.
Others have evolved very well to living in extremely low-light environments. Consider tall and dense rainforests; little light reaches the ground, yet these plants have evolved to survive and flourish in high humidity and low light.
Due to the fact that certain plants need more light than others, your houseplant may either live contentedly for the rest of its life in a dark corner or in a bathroom without windows, or it might perish rapidly in such circumstances.
To determine how much sunshine a plant requires, we use illuminance or lux, which is a measurement for measuring the intensity of light striking a surface. To really grasp the concept of lux in the real world, here are a few simple examples that everyone may comprehend:
| Surface | Illuminance (lux) |
|---|---|
| Clear night sky | 0.2 – 0.5 |
| Standard living room lights | 100 |
| Sunrise or sunset | 400 |
| Office lighting | 300 – 500 |
| Overcast day / Studio lighting | 1000 |
| Full daylight, not direct Sun | 10 000 – 25 000 |
| Direct sunlight | 32 000 – 100 000 |
As you can see, there is a significant difference between how much sunshine your house plant receives in the living room and how much sunlight it receives outdoors in direct sunlight.
Having a method to properly monitor the quantity of light reaching your plants can go a long way toward helping you produce healthier plants. To do so, you will need a Lux meter. Lux meters may be costly and inaccurate, so exercise caution and do enough research before making a purchase.
With the information above, we may classify plants into three broad groups depending on their photosynthesis requirements.
Take note that this is a broad generalization.
Plants that need low light (500 – 2.500 lux/day)
These are often plants that have evolved to low light conditions and can grow with as little as 50 lux/day. Generally, they are tropical plants that thrive in humid conditions, although this is not always the case.
Snake Plants are an excellent example of low-light, low-humidity plants. Indeed, many of these plants will get leaf burns as a result of direct sunshine exposure. They are easily identifiable by their profusion of green leaves and the fact that they do not bloom as often or as brilliantly as other plants.
They adhere to the “green rule,” which states that the more green leaves they have, the more they may benefit from low light circumstances.
The following are a few instances in no particular order:
- Dracaena
- Evergreen in China
- Bromeliad
- Plantain spider
- Plantain snake
Plants that need a moderate amount of light (2.500 – 20.000 lux/day)
While medium-light plants may live in temperatures as low as 250 degrees Fahrenheit, they need more than that to grow and bloom.
Medium-light plants, on the other hand, are excellent suggestions for novices. They often conform to the traditional notion of plants. You just provide them with water and sunlight and watch them develop. Additionally, they bloom beautifully and provide a dash of color, which keeps novices interested.
As a general rule, these plants want everything to be medium. Additionally, they like mild temperatures and moderately wet soil. Because these plants can not tolerate extremes, you may position them at least 5 feet away from a sunny window.
Several examples:
- Violeta africana
- Begonia
- Croton
- Cane incomprehensible
- Palm of Kentia
Plants that thrive under bright light (20.000–100.000 lux/day)
To live, these plants need at least 2000 lux/day, and much more to flourish and bloom. Typically, these are plants that developed in deserts or under circumstances of continuous direct sunshine. As a result, they prefer drier circumstances and are used to their soil being drier.
They should be put near a window or in any location that gets at least five hours of direct sunshine each day.
Several examples:
- Numerous cactus species
- Additional succulents
- Plantain jade
- Hibiscus
- Areca nut
Thus, can plants grow in the absence of sunlight?
Technically, no, but there is one exception.
Then how long can any plant live in the absence of sunlight? Consider the table below.
NoteThis is a broad generalization that varies significantly across species; for example, cactus need much less light than other plants during hibernation.
| Plant type | Necessary lux/day | Survival period with no sunlight ( ~0 lux/day) |
|---|---|---|
| Low light plants | 500 – 2 500 | 14 – 20 days |
| Medium light plants | 2 500 – 20 000 | 10 – 14 days |
| Bright light plants | 20 000 – 100 000 | 4 – 10 days, except hibernating cacti |
Can plants survive in the absence of sunlight? Experiment
How are we to verify this? I propose that you do the following experiment, which some of you may recall from school. Additionally, it is referred to as the closet experiment.
- Take a notepad and pen with you if you wish to keep track of the phases and when they occur.
- Take one houseplant in a pot. Maintain a traditional look with a houseplant with medium-light green foliage.
- Place the house plant in a dark, well-ventilated closet with enough room. You may continue to water it since this is a no-light experiment. It will produce much quicker results if you feed it water but it lacks the fuel necessary to accomplish anything with it.
I do not want you to accidentally kill your favorite houseplant, so allow me to take you through the remainder of the experiment’s phases and what will occur.
The first phase is characterized by pale leaves.
They are no longer able to generate enough chlorophyll, which is also responsible for the leaves’ green color. As a result, they lose their green hue and their capacity to utilize sunlight for energy. The leaves will turn yellow and eventually fall off.
Phase two – lanky plant
Perhaps you have heard the phrase “leggy plant.”
This is an incredible phenomena in which if a plant does not get enough sunlight, it grows in an attempt to obtain more sunshine. As a consequence, it grows too lengthy and collapses.
These are trying times.
Phase three – demise.
I believe the phase’s name is self-explanatory.
There are certain plants in the plant world that we did not include here; they are the only plants that can survive in the absence of sunlight or artificial light; these are parasite plants.
Parasitic plants, the family’s black sheep
Certain plants can thrive in the absence of sunshine; they do not even need artificial light, and they are very scary.
Parasitic plants live by sucking energy from their hosts, much like a plant vampire. Certain plants can even do both photosynthesis and energy theft from their hosts. They, like Mistletoe, are hybrids.
Because they do not need leaves, they lack the color green, resulting in alien-looking plants. Some of them are magnificent, with ghostly hues and the appearance of tiny flowers sprouting from the ground, such as this lovely Indian pipe.
If you are interested in parasitic plants and want to learn more about them, go here for an introduction to their world.
Which Plants Can Be Overwintered Without Grow Lights in the Garage?
Many houseplants may survive the winter in a garage, but perennials cannot, since they need particular light and temperature conditions to bloom.
Many plants will live as long as the temperature is above 40 degrees Fahrenheit.
The following plants may be overwintered in a garage:
- Persian sabre
- Coleus
- Begonias
- Fuchsia
- Hydrangea
- Agapanthus
Although they will not develop, some fig trees may survive the winter in a garage.
To get the greatest results, heat your garage or keep your plants close together–they will retain a little more heat this way.
If you are interested in growing vegetables inside, you will want to read our whole article on growing vegetables indoors using grow lights.
They will remain warm if placed near a window that receives enough sunlight–or you can supplement overcast days with artificial light.
In general, you will want to maintain the temperature above freezing while overwintering plants in a garage, since freezing may harm plant cells and tissues, eventually killing the plant.
Can you grow plants in the absence of natural light?
The simple answer is yes, plants can live and even flourish under artificial light; note how I did not explicitly mention sunlight when I explained photosynthesis. The only reason plants can thrive in the absence of sunshine is because humans utilized our enormous brains to develop artificial light.
That is how we learn from textbooks since that is how plants evolved, but the chemical responsible for the process is unconcerned about the source of light as long as it is delicious.
What delicious implies for your houseplant is a light source that emits the wavelengths necessary for it to utilize the light as fuel. Remember how Einstein, the little guy with a huge brain, said that light may also travel in waves? As it turns out, it is critical plant information.
The catch here is that the sun supplies the whole light spectrum, which plants need throughout their various development phases.
That is where the name “growth light” originates from, and they are designed to supplement or give the entire spectrum of light required for your plants to flourish.
When it comes to the finest growth lights, there are three broad areas to consider:
HPS lights are sometimes known as high-pressure sodium lights.
These are the most powerful, but also the most costly in general. If you just need a little amount of light to develop a houseplant, I would avoid them; they are a bit excessive. However, if you are looking for a strong, dependable growth light, they are excellent.
Here is an excellent illustration:
VIVOSUN 1000 Watt HPS Hydroponic Grow Light
Fluorescent illumination
As you can see, they are less expensive and more convenient, but they are not as safe, and they do not function as well for novices unless you know what you are purchasing. However, if you just need light for a few houseplants, the following are the greatest options, and I would strongly suggest this one:
Agrobrite FLT24 T5 Fluorescent Hydrofarm
LED luminaires
They are priced in the middle. Additionally, the price may vary significantly. A few years ago, LED grow lights were considered a luxury item; today, they are the prudent option.
They are very safe and flexible, but they are less practical when a large amount of power is required. Having saying that, you can generally find what you are looking for. I have included a link to a highly strong example below, but you can find them for much less if you do not need that much power:
3000W BESTVA DC Series LED Grow Light
While not all artificial light sources are created equal, all artificial light sources may be used to supplement or replace natural light.
Choosing between them may be challenging and can save you a lot of money, so if you are searching for answers to all your concerns, check out my post on how to pick the finest grow lights for your requirements.
All this discussion about light may cause us to overlook something critical: darkness or a lack of light is just as significant.
Another thing to keep in mind is that plants thrive in darkness as well. As with us, they need a period of rest during which they may just enjoy a good night’s sleep, which is why it is important to give your houseplant a break from feeding.
Plants are really amazing, and if we look after them, they will look after us, even if it means inhaling more plant crap.
Reviews by Others
Lisa says:
All plants need light to perform photosynthesis in order to use and grow nutrients, and without it, they cannot live to maturity.
While many plant species may theoretically thrive in the absence of light, they are unable to develop, function, or reproduce in their natural state. Without light, seeds may germinate and tiny roots and seedling plants can develop, but they will be weak and unlikely to survive until put in a bright environment.
1.Lords and Ladies: This is one of the most renowned flowering plants found in almost every garden. Additionally, it is often referred to as cows and bulls, adam and eve, demons and angels, and so forth.
2.Geranium Cranesbill: This is one of the most lovely flowering plants for dry shade. The Geranium Cranesbill is a fluffy tiny mound of leaves with white blooms that can come in hues of blue and pink.
3.Barrenwort: This is another dry shadow flowering plant that requires just a little amount of sunshine to thrive. The flower extracts are utilized as an aphrodisiac.
4.Mourning widow: This plant bears blooms that are blackish in color and resemble those of a mourning widow. The dry shade plant thrives in regions densely forested with trees and bushes.
Marry says:
Photons are the units of energy that the sun gives to plants.
Therefore, if you want to develop a plant in the absence of sunshine, you must locate a source of photons for the plant. Photons are also emitted by a torch, a light bulb, or any other artificial light source.
However, plants contain photoreceptors that absorb light at particular wavelengths. That is why the artificial light we employ must have the exact wavelength balance required by the plant.
At this point, the usage of grow light becomes necessary. Grow lights produce light with the proper wavelength for photosynthesis. Different grow lights are more suited to certain kinds of plants. The light should be positioned as closely as possible to the plant without scorching the leaves.
I hope this is of assistance 🙂
Linda says:
It is situational! Plants get nutrients in a number of ways. In general, plants need sunshine to synthesize sugars that provide energy in the form of ATP. Certain plants, such as Epifagus virgiana, or beechdrops, need neither sunshine nor leaves. Beechdrops feed only on the nutrients found in beech trees.
In conclusion, the majority of plants need some amount of sunshine. There are significant exceptions, though.
Conclusion
We have discovered that sunshine is a critical resource that every single plant, regardless of their location on the planet, need in some way or another.
Whether via the normal process of photosynthesis or the particularly specialized and unique method that plants such as cyanobacteria and parasitic plants undergo, each and every plant absorbs and utilizes the sun’s light.
Plants, like humans, need light to flourish. However, just like any other living creature, they control the quantity of sunlight they take to ensure healthy development and survival.