Sunlight is essential for trees to produce food and improve their growth. Almost all plants require light to survive for longer, except a few show sensitivity towards it. Moreover, they can absorb specific wavelengths to use in photosynthesis, which are not provided by LED lights.
How Long Can Plants Survive Without Sunlight? Plants can survive without sunlight for almost 3 to 20 days, depending on their requirements for light exposure. Due to their sensitive nature, some need a continuous light source to survive only for 3 to 10 days. However, a few have a better tolerance to the unavailability of light and live for almost 14 to 20 days. Furthermore, some plants are photosensitive and parasitic, which do not require sunlight and depend on nearby trees’ roots to get nutrition.
Many factors are responsible for the unavailability of light, like the changes in weather, the winter season, or the presence of a garden in a shady area.
You have to determine the nature of your plant, whether it is light sensitive or requires bright light for better growth to ensure their better survival.
Is sunlight essential for plant growth?
They are not dependent on others for their food and absorb light from the tiny holes in the stem, leaves, flowers, etc.
Sunlight is essential for preparing food as photosynthesis only occurs in the presence of light.
It acts as a fuel that helps initiate chemical reactions to break water and carbon dioxide molecules. The sun’s energy allows carbon dioxide and water to react to produce food.
Furthermore, the photosynthesis process boosts when the light intensity increases, while they have to suffer from low energy when you place them in the dark area.
How much sunlight do plants need to survive?
They need exposure to light to survive stressful conditions and produce food to fulfill their nutritional requirements.
Moreover, you have to expose them to direct or indirect sunlight for almost 14 to 16 hours a day.
This exposure helps them use solar energy and produce chemical energy, boosting their metabolic processes.
This time duration varies for every plant type, as flowering plants need only 6 to 8 hours of sun exposure. At the same time, you can keep them in the dark for almost 16 to 18 hours.
In addition, other types, including those that cannot live without sunlight, need it for 24 hours, or some can survive under 12 to 16 hours of exposure.
How long can plants live without sunlight?
Their survival in the absence of sunlight depends on their age and nature. Some of them are photosensitive, which means they cannot tolerate sun rays.
However, photosynthesis occurs quickly in younger plants as they require more energy than older ones.
The energy requirement determines the need for light as many plants need only low to medium, while a few need bright light exposure.
Light-loving plants can die within 3 to 12 days when they do not get sufficient light to survive.
However, those having less dependency on sunlight can survive for almost 14 to 20 days without any light.
What happens to plants without sunlight?
You can see different changes in their internal systems and physical appearance when they cannot get sufficient light to keep their internal mechanisms in the process.
Dormancy
When there is insufficient light for them to grow, they enter a dormancy stage and halt their growth.
It is a survival mechanism during unfavorable conditions like the absence of nutrients, water, and light. It removes extra body parts like leaves or stops the processes of surviving under stress.
Moreover, the dormancy stage breaks when you put them back into the light.
Changes in leaves’ color and texture
The color of leaves begins to change when there is no photosynthesis as they cannot produce chlorophyll.
It appears pale green and yellowish due to the absence of chlorophyll. Moreover, they can die when you do not give them a proper source for a long time.
They begin to get dry and brittle in texture as photosynthesis cannot use carbon dioxide and water from the environment to provide them nutrition.
Wilting is a common effect of low light exposure to plants that cannot live without it. It can resist the stress for only 2 to 3 days, but you can observe wilting of leaves and the stems gradually.
Legginess
Legginess means the overgrowth of plants in a vertical direction that can increase overall height.
It tries to reach higher in the sky in search of sunlight, as longer stems have more direct exposure to light. So, it appears long with a thin stem that begins to swing on one side.
Only a few leaves appear on the top end, but average growth starts if it gets proper bright light.
Death
This last phase occurs only when there is no light source for many days. It can die when it suffers from a deficiency of chlorophyll and food.
The light-loving trees can die within 2 to 3 days when they cannot find a suitable source, while the others take almost 14 to 20 days to survive without light.
Their phytochrome activates when it is struggling to find energy source. The seedlings are elongated thin structures when they do not contain chlorophyll or show etiolated growth.
What type of plants can survive without light?
Photosensitive plants cannot survive in bright light and prefer to live in low or shady areas. Direct exposure can damage their structure leading to death.
You can keep the snake plant in the dark without worrying about its lifespan, and it can maintain its glory to the fullest. This is because sword-like stiff leaves can store water for longer.
Moreover, Dracaena require low to medium light exposure to survive, so that it can be a good choice for indoors.
Bromeliad is sensitive, or you can keep it at a place where indirect light reaches the leaves. However, a long time of exposure can cause severe damage to the whole structure.
Spider plants can live under such conditions without severely impacting their growth. Furthermore, it is not difficult to handle due to its versatility to grow under low or poor conditions.
Some are adapted to lesser light when you keep them growing in a shady area for a long time.
In the same way, cacti, orchids, and Chinese evergreens can live a healthy life when you keep them away from the sun.
Furthermore, parasitic plants like Orobanche are chlorophyll deficient and dependent on the roots of other trees to get food and nutrition. The mycoheterotrophic do not need light as they rely on fungi for their food.
What type of plants cannot survive without sunlight?
The light-loving plants, including the Jade plant and lavender, cannot live without light. It has severe effects on their development and allows them to grow at a fast rate.
Some require continuous sunlight exposure of 20 to 24 hours, like the Coleus and Swiss Cheese plant. However, you can place them under the sun directly as it does not affect them.
Moreover, this requirement varies between different species, but continuous exposure is not ideal for them. In nature, two types of cycles work, light and dark.
It cannot allow photosynthesis as they need time to use the energy produced in the daytime. Therefore, it is better to follow an exposure pattern and keep them in light and dark for an appropriate time.
However, some show better performance when you increase the exposure time, like lettuce.
Can LED lights be used as a replacement for sunlight?
It is better to consider some factors while choosing an ideal light source for your plants. For example, the number of plants in the garden and the total space for them matter a lot.
In addition, the flow of people, total budget, and the distance of the light source help determine the efficacy of LED lights.
It is better to use LED lights as a replacement for sunlight when you want to place them closer to their surface due to a shortage of space.
One of the main benefits of these bulbs is that you can easily change the color according to the requirement of the plant.
As red light promotes the growth and blooming of fruits, a blue-colored bulb help conserve energy in vegetables.
So, LED lights are an excellent alternative to use when there is no sunlight in the garden to ensure their survival.
Can a plant survive in a dark room?
Some plants are perfect for growing in a dark room or cannot tolerate bright light exposure. Devil’s Ivy cannot live in a sunny area and is considered the best option for indoor gardening.
It can grow on the walls as it does not require sun energy to bloom. Peace Lily requires no sunlight to grow; otherwise, it can damage its leaves.
You have to place it in a dark place and provide sufficient water regularly to maintain it. It can damage their leaves or stems, resulting in death.
How do indoor plants survive without sunlight?
They need sunlight to conduct photosynthesis, so you have to prepare an artificial light source when you want to grow them indoors.
You can install LED bulbs, fluorescent lights, and metal halide bulbs to ensure their growth.
The LED lights are expensive and cost around $150 to $200, but they produce less heat than other bulbs.
It is challenging to fix them on a shelf, but their safety makes them a suitable choice in a room full of green plants.
Fluorescent lights are cheaper than metal halide bulbs but produce less power. Placing them on a shelf or small space is convenient due to their narrow size and lesser heat production.
Moreover, they do not need proper ventilation and avoid fire hazards. However, it contains chemicals that can pose safety risks in case of breakage.
High-pressure sodium lights are costly but powerful sources as they can emit almost 990 to 1000 Watt of light.
Therefore, it is good to install metal halide bulbs when you have a large-sized greenhouse at your home.
Moreover, it is better to use some other alternatives when you have a small garden in the backyard where your pets are wandering.
They produce heat that is not suitable for your children, so avoiding their use in small spaces is recommended.
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