Do Tomato Plants Need Direct Sunlight? What to Know
Tomato plants depend on the sun for energy and the production of carbohydrates through the process of photosynthesis. The term photosynthesis is derived from two words i.e. photo, which means light, and synthesis for the production of carbohydrates. So, do tomato plants need direct sunlight?
For healthy growth and blooming, tomato plants require at least 8 hours of direct sunlight a day. Adequate sunlight together with ample conditions such as moisture, nutrients, and other maintenance will guarantee high yields.
How much sun do tomatoes need?
The least amount of sunlight a tomato plant requires in a day is 6 hours. However, to maximize growth rate and increase the yields, you may be required to provide your plants with 8 or more hours of sunlight per day.
Tomato plants require sunlight together with adequate moisture and nutrients to produce energy they use through the process of photosynthesis. However, as a gardener, you are supposed to maximize the light and reduce the harmful side effects of heat on your plants.
The light and heat intensity from the sun varies throughout the day depending on time. Therefore, it is categorized into three stages that include:
1. Morning sunlight
Morning sunlight has numerous advantages for your tomato plants as compared to the noonday sun. It provides high-intensity light to your plants without the excessive heat that is common on noonday.
It also helps to evaporate moisture or dew that may have accumulated on the leaves overnight. Moisture on the leaves exposes your plants to health risks such as fungal infections.
If you are staying in a location where heat levels increase in the midday, you may consider exposing your tomato plants to morning sunlight and sheltering them during the midday. If the morning sunlight is less than 8 hours, your plants will require additional sunlight in the afternoon for healthy growth.
2. Midday sunlight
Midday sunlight occurs between 11 a.m. to 2 p.m. This is the time of the day when the sun’s rays are at their optimum temperature. The plants receive a lot of sunlight that they need but it is unfortunate that the light comes along with a lot of scorching heat.
Tomato plant requires a lot of light and not excessive heat. Hot midday sunlight can have negative effects on the growth of your plants. It physically damages the plant. Watch out for signs of excess heat such as:
- Changes in the color of leaves. The pigment will appear washed out or bleached.
- Burns or scorches on the leaves that may appear in white, brown, or yellow colors.
- The texture of leaves changes from soft to scaly, wrinkled, or crispy.
Before you start to experience the above symptoms on your plants, it is best to find a way of protecting them against excessive sun. If you have planted your tomatoes in pots, it may be easier to transfer them to an area that has shade.
To protect tomato plants planted directly in the field, you can construct a structure and cover it with dry branches to provide shade for the underneath growing plants. Alternatively, you can plant a vining crop that will climb and crawl on the structure to provide maximum shade during the day.
3. Afternoon sunlight
Afternoon sunlight is also ideal for the healthy growth of tomato plants. It contains the necessary ultraviolet radiation required by the plant without having a scorching effect. You can utilize the morning and afternoon sunlight to give your tomato plants healthy growth.
Do tomato plants need direct sunlight?
The simple answer to this question is yes, tomato plants need direct sunlight for healthy growth and high-yield production. The ideal amount of direct sunlight a tomato plant requires may vary depending on the stage of growth. i.e.
Seedling stage
When preparing to grow tomatoes, you will start by germinating the seeds. The process of germination requires only air, warmth, and water. After the seeds have germinated into seedlings, it is recommended to expose them only to the morning sunlight.
During this stage, the plant is normally tiny and fragile. It can easily be scorched by the sunlight. Sunlight is very important during this stage. It prevents the plants from becoming leggy during the process of searching for light. Therefore, it is good to expose your seedling to direct sunlight in the morning before taking them back in the shade when almost midday.
Growth stage
This is a growing period after the plant is transplanted into containers or directly into the field. In this stage, the plant growth is rapid and it requires maximum sunlight, adequate water, and ample nutrients to provide energy to itself in the process of photosynthesis. When the growth conditions are favorable, the plant is likely to double its mass after every two weeks.
Flowering stage
Flowering is a very crucial stage in the growth of a tomato plant. When you mess with flowers, it simply means that you will not get the fruits. Excess heat from the sun can result in tomato flowers falling off the vine or withering without setting fruits. The temperature is supposed to maintain below 32 degrees Celsius during this stage.
Fruiting stage
This is also a very delicate stage, a small mistake can cost your entire labor. Young tomato fruits are likely to be affected by sunscald if necessary measures are not put into place. However, the plant requires a lot of energy during this stage. Therefore, the plant may require more than 8 hours of direct sunlight exposure.
Ripening stage
For determinate tomato varieties, when the ripening stage arrives, the plant requires little sunlight and nutrients. The ripening process is stimulated by the hormones produced by the plant. Therefore, you may pick the fruits and store them somewhere in a kitchen cabinet to ripen fully before use.
Can tomatoes grow in the shade?
Yes, tomatoes can grow in an area that has low light but will not be productive. Tomato plants require high light intensity, adequate water, and nutrients in order to produce high yields. Scientifically, tomatoes can germinate but cannot grow in an area that is completely dark.
There are some tomato varieties like cherry that can grow in a shade or in an area that has low light intensity. However, the production is normally low as compared to when they are grown in an area that receives sunlight for 8 hours a day.
Tomatoes require a temporal shade during the day only if the heat from the sun is too high. It helps to prevent the scorching effects of the sun. Tomato plants like sunlight a lot, therefore they are likely to miss out on the essential amount of sunlight when you plant them in a shade.
If your garden is covered in shade or located in an area with low light, there are various ways you can use to enhance the light. For instance, you can use mirrors to reflect sunlight on your plants or paint the walls with bright colors in order to reflect more light on your plants. Alternatively, you can use artificial lights.
How much sun is bad for tomatoes?
Tomatoes do well in temperatures that are below 32 degrees Celsius during the day and 24 degrees Celsius at night. Excess heat that is above these temperatures may have a negative impact on your tomato plants.
Too much sun on tomatoes is characterized by burns on the leave and fruits, pigments on the leaves that appear bleached, and a change in the texture.
Excess heat from the sun can also result in sunscalds on the fruits. This is a phenomenon whereby a part of the fruit exposed to the sun develops a patch or a region of discoloration. The patch becomes hard and may start to rot. Too much sun can be prevented by:
- Keeping the tomato variety that requires low light intensity in a shade. Alternatively, they can be grown indoors in an area that does not receive direct sunlight.
- Planting your tomatoes in an area that receives shade in the midday when there is a lot of heat from the sun.
- Providing a temporal shade in the middle of the day or when temperatures exceed 32 degrees Celsius.
- Practicing hardening off before moving or transplanting your tomatoes in an area that receives bright lights or more heat.
- Ensuring your plants are adequately watered in the morning before the sun is out.
Final Thoughts
For healthy growth, tomato plants require 8 hours of sunlight per day. If you are practicing indoor tomato gardening, you can go for a variety that requires low light intensity and supplement the lighting with grow lights.
