Does Soil Need Sunlight? Here’s Why Not & Soil Protection

Does Soil Need Sunlight? Here’s Why Not & Soil Protection

Unshaded soil can become problematic since sunlight can destroy living things and dry up the soil. However, it is possible to cover both garden and potting soil to offer protection from the sun’s harsh rays.

Sunlight is not a direct requirement for soil. Climate, air quality, water, and organic matter all affect soil fertility. However, living things in the soil, such as cyanobacteria and algae, are directly impacted by sunlight. For these organisms to create carbohydrates that are good for the soil, they need sunlight.

That’s not it, though! At first glance, everything may appear to be so straightforward and uncomplicated, but this is not the reality. The way sunlight affects soil depends on a number of variables.

The following components give specific information about how sunlight affects soil.

How Does Sunlight Affect Soil:

Sunlight doesn’t directly effect the soil, as was already established. Instead, it has an impact on the microbes on or below the surface. Algae and cyanobacteria are a couple of these microbes.

These organisms produce carbohydrates and other crucial soil nutrients. The soil needs sunlight to become productive for plant growth.

With the aid of sunshine, plants synthesize their food, and the more photosynthesis that occurs, the better for the soil.

The next factor is solar radiation, which is the intense heat that comes from the sun and is absorbed by the soil, raising the temperature of the soil.

A rise in soil temperature can be advantageous or detrimental. It has the ability to either boost the amount of nutrients in the soil or rapidly destroy the inside microbes.

In other words, warmer soil is more fertile than cooler (lower temperature) soil.

Warmer surroundings tend to have more active microorganisms than cooler ones do.

The soil will dry out and start to shrink, pulling apart from each other, as a result of too much sunlight causing too much water to evaporate from the soil.

This is clear from the huge, noticeable fractures along the soil’s surface in arid regions. These effects, which can also impair garden soil and lawn areas, are restricted to arid locations.

Do Microorganisms in Soil Need Sunlight?

They do, that much is certain. Yet how? Although bacteria require relatively little sunlight to grow and produce the essential nutrients in soil.

According to a study, microorganisms can distinguish between light and dark. So, exposure to sunshine may increase the threat of bacteria.

Algae and cyanobacteria, on the other hand, need almost as much sunlight as plants. Photosynthesis is what they do. One of the oldest known life forms and a contributor to the existence of oxygen on earth is cyanobacteria.

The most plentiful and renewable energy source on planet is sunlight. Of fact, sunshine is also necessary for microbes to proliferate in soil.

The presence of sunshine is necessary for algae to flourish. As a result, ponds or other bodies of water that receive more sunlight develop more algae than those that receive less.

These bacteria, like algae, have chlorophyll, which allows them to convert sunlight into chemical energy, directly influencing the growth of algae.

Algae may die if their access to sunlight is cut off.

Overall, for growth and development, microbes like algae and cyanobacteria require sunshine.

Does Sunlight Cause Weeds to Grow on Soil?

Yes, weeds do indeed grow on soil due to sunshine. However, when exposed to sunlight, weed seeds can develop remarkably well. Marijuana, also known as weed, belongs to the Cannabaceae family. There are either male or female plants in this family.

To flourish, weed plants need soil that is rich in organic materials. They also require 10 to 13 hours a day of direct sunlight.

In other words, sunlight is what makes these plants the happiest. In addition to consistent sunlight, marijuana plants must to maintain control over various light wavelengths.

Cannabis plants, like other plants, have chlorophyll, which transforms light into food energy. Simply put, you need to place your marijuana or cannabis plant in sunshine from sunrise to sunset if you want it to expand enormously.

Will Using Fabric or Mulch To Prevent Sunlight, Affect It?

Mulching the soil could be beneficial for it, but covering it with fabric or landscaping fabric might not be the best idea.

When it comes to lining the soil with landscape fabric, the disadvantages outweigh the advantages.

The soil can be protected from weed growth by covering it with fabric. Additionally, it keeps the soil moist and reduces the need for weed control. The plant eventually dies as a result of the decomposed soil particles obstructing the fabric holes and making it impossible for the required amount of water to reach the roots over time.

Additionally, it stops earthworms from aerating the soil, which results in unhealthful soil. Over the cloth, marijuana can still grow in mulch.

Mulch, on the other hand, is a somewhat different scenario. Mulch also aids in maintaining soil moisture, enabling vital components to enter plant roots and ultimately leading to healthy plants.

The Benefits of Mulch

  • keeps the soil moist, preventing water loss from the soil.
  • Additionally, it inhibits weed growth quickly, and most critically,
  • defends the soil from extreme temperatures, particularly cold.
  • consumes soil degradation, resulting in improved soil health.

The Benefits Of Soil Cover Against Sunlight


Can water drain from the landscape fabric? It does, indeed. For you, though, there are both good and bad news. How? Air and water can pass through landscape cloth.

Use landscape fabric if you think it will help, but wait until you notice soil deterioration obstructing the flow of either air or water.

On the other side, mulch helps the soil’s drainage over time. By gently decomposing to assist drain the water and maintain the moisture, it enhances soil structure.

Weed Growth

Landscape fabric can help with weed control, but it’s not ideal. The fabric must first be exposed to both air and water. However, after time, soil decomposition will begin to accumulate on cloth, allowing weeds to grow there.

Thick mulch spread over weedy regions stops the weed from regrowing. But before it gets a chance to go back to seed and emerge a second time, it needs to be manually removed off their heads.

For information on removing landscape fabric from garden soil, see our in-depth article.


By absorbing the sun’s heat and then transferring it directly to the soil below, mulch helps to keep the ground reasonably warm. In the winter it might be beneficial to the soil, but not in the summer.

Mulch may make already warm soil even warmer, which could be bad for the soil. Nothing ever benefits from overheating, right?

It doesn’t really matter if temperature has a detrimental or positive impact on the composition of the terrain.

Water Retention

Mulch is excellent for retaining water in soil. It is mulch’s main characteristic. Simply explained, mulching the soil blocks out direct sunshine, which causes a substantially smaller amount of water loss.

Landscape cloth is not intended to hold water. Instead, it is porous to water, which makes it easy for moisture to pass through and escape.

The goal is to prevent the soil’s surface from being directly hit by the sun’s beams. By doing this, the soil is actively kept from losing a lot of moisture.

Soil Pests

Mulch has proven to be ideal in the aforementioned instances. But here? Not really. For soil pests, mulch can be the ideal place to live and breed.

Applying mulch so close to your house may not have been the finest move because it would have given your small hidden enemy access to your dwelling.

Will Covering Soil Prevent Weeds?

I say, “Yes!” It will. The weeds will be eliminated by covering the soil with plastic sheets, leaving you with a good garden area. You can use landscape fabric here by laying it on bare soil around tree trunks.

It will stop the weeds from growing and inhibit their ability to absorb nutrients and water.

In addition to covering it with sheeting materials, rocks and sand also have advantages of their own.

Because they stop water loss, bugs, weeds, splashing, soil loss during irrigation, and pet contact with the soil, rocks can be used to cover the topsoil in potted plants.

Sand, when used as a mulch, improves the appearance of the garden by providing a white background that contrasts with the greens of the plants. Additionally, it stops the growth of weeds and guards the topsoil from water loss as well as insects and fungus. It can also be applied as an amendment to improve the aeration and drainage of the soil.

The Takeaway:

Direct sunshine is not necessary for the soil to be alive underground or in the dark. Methane and organic molecules found in the soil are used as food by microbes and the roots of plants below the surface.

However, there are countless microorganisms in soil that do require enough sunshine to flourish and sustain soil fertility (somehow).

Sunlight is necessary for the growth of living things in the soil, including cyanobacteria, algae, and fungi, which create carbohydrates that are good for the soil.