Just like nature’s cycle of light and darkness, plants need some hours of darkness every day to maintain a healthy balance. The effect of both light and darkness has a more profound effect on plants than having only light or darkness. Taking care of plants can be relatively easy as they generally require water, light, and a conducive environment. However, their individual needs vary as some plants require more water than others with other plants needing more light than others. Despite the fact that plants need light to grow, constant exposure to light can damage our plants. Plants just like human beings require a few hours of darkness in order for them to rest and perform other metabolic functions. Whether our plants obtain their light from a natural source i.e. the sun or artificial sources such as fluorescent lights or red and blue lights, they should be kept in the dark for a certain amount of time per day.
Light is a vital component of a plant’s development due to its involvement in the photosynthetic process. Photosynthesis refers to the process through which plants make their food by incorporating moisture (the roots absorb moisture from the surrounding soil), Carbon dioxide, and light (this gives the chloroplasts energy to make the sugars). This process releases oxygen as a byproduct and in most plants; it takes place during the day in the presence of light. At night, when it is dark, our plants take that time to metabolize the food they made during the day and release certain factors that promote their growth. How light affects the growth of plants in various ways can be defined using two main terms. These are;
- Phototropism- this is how plants grow in pursuit of light. Shoots grow towards the light with the roots growing away from the light.
- Photoperiodism- the developmental processes of a plant such as flowering follow a day’s length. Therefore, some flowers bloom when the days are long while there are others that bloom when the days are short.
Both processes determine how well our plants will do and are also regulated by the presence of light. This demonstrates the importance of light and its regulation to a growing plant.
Can plants be in light all the time? No, most plants have been shown not to thrive if kept in the light 24/7. The light/dark balance has been shown to be the most ideal kind of environment for the plants. However, certain plants have been known to do well when constantly kept in the light such as the rose family.
How do You Know if Your Plant is Getting too Much Light?
Different species of plants require varying amounts of light. Some thrive best indirect light (the plants are in direct sunlight for 2-3 hours every day), most of these are desert-adapted plants such as cacti. Other plants will do best in indirect bright light (this is achieved when the plants are in a light-filled room for most of their time but not when the sun is at its hottest around midday to 2 pm). Finally, some plants prefer low light and can be kept in dimly lit areas or turned away from the light to minimize exposure.
When we expose our plants to too much light, there are several signs our plants can exhibit to give us a hint. Some of these telltale signs include;
- Burned patches on the leaf
- Signed tips
- Falling off of leaves
- Yellow leaves
- Brown, crispy leaf edges on the tips.
What Happens When Plants Get too Much Light?
When a plant is exposed to too much light, it absorbs a lot more energy than it can handle and this results in the creation of Reactive Oxygen Species (ROS) which are highly toxic to the plant. When plants are exposed to high light intensity, some of this light energy is converted to heat which results in plants having to find cooling mechanisms. One of the ways in which plants cool themselves off is by using some of their water to cool themselves off. This can result in dehydration if the plant is using a lot of water to cool itself but not having its water replenished just as fast.
If this process is not corrected, this can deplete the plant’s water reserves and leave no water for vital processes such as photosynthesis. The resulting signs observed are a result of this process. Some researchers have however speculated that plants developed a mechanism to deal with being in the light for so long and they, therefore, do not create the Reactive Oxygen Species in the first place.
How Much Light is too Much for Plants?
When considering how much light is enough for our plants. We look at two main things, these are; light duration which refers to the amount of time the plants were in the light, and light intensity which refers to the quantity of light per unit area. For the most part, light duration does not really affect plants as much as light intensity does. If the light duration is altered, the blooming of the flowers will be affected and so will its growth cycle, however, light intensity alteration affects plant growth more.
This being said, we can therefore conclude that for short-day plants, more than 12 hours of light is too much light while for long-day plants, not having periods of darkness for the plant can be considered too much light. If living in a house with little natural light you could get an artificial source of lighting to accentuate the amount of light the plant gets. An example of artificial lighting used is this 45W LED EMMSUN Grow Light with different hour cycle settings. Find out more by following this link.
What Happens if Plants Don’t Get Enough Light?
Owing to the fact that plants require light to grow due to the role it plays during photosynthesis when plants receive inadequate light, there can be certain repercussions. When plants do not receive adequate light, they grow too long too fast in search of the sun in a process known as etiolation. This process results in a plant with very long stems but very weak stems. In addition to that, a plant that is grown in less light conditions than it requires begins to develop a faded color, long internodes, and fewer leaves. In as much as light is a very important factor for growth, plants can survive a long while even in inadequate light conditions which is how plants survive during winter conditions when the nights are longer and the days are not too bright.
When we catch our plants looking like this, we should move them to an area of the house or garden where their needs will be met. Plants recover pretty quickly and they start looking more alive in no time. However, if the light conditions are not improved, the plant could grow too weak and die off early especially due to the lack of photosynthesis which translates to a lack of food for the plant.
If living in a house where your plants receive inadequate light, artificial light can be used to give the plants their light requirements such as this 600W LED Plant Grow Light from Philzon. Find it here on Amazon and learn more about it. You could also prefer this 40W Grow Light with a stand with a red-blue spectrum for your indoor plants. Read more about it here.
Final Thoughts
Light is an important component of a plant’s growth. Light plays a vital role in photosynthesis where it gives energy to chloroplasts to make sugar. This process also makes use of water and Carbon dioxide. This thus means that light is important for plant growth however, the amount of light we expose our plants to needs to vary depending on the plant’s individual needs. Plants can either prefer direct light, indirect bright light, or dim lighting. Remember, it is imperative to understand our plants to encourage their growth.
Certain plants can continue to do well even when kept in the light 24/7 but there are those whose growth cycle will be affected if kept in the light constantly. One consideration would be how much light the area you would like to place your plant in receives. Most people place their plants on windows or balconies that receive adequate light daily. At night, in the absence of light, plants break down the food they made during the day and this encourages growth and some flowers bloom better when exposed to periods of darkness. It is therefore important to ensure you balance the amount of light your plant receives.