There is more than one way to solarize a garden bed.
We all know that solar products or solar energy sources are found in almost every other house.
Every person, even you and I, also wish to use solarization in each aspect we can, whether to save electricity or to use solar power materials for eco-friendly purposes.
Also, solar power has now become the cheapest and eco-friendly source of energy that allows us to enhance the environmentally friendly method of optimizing power.
Today, we have a variety of solar-powered devices.
They’re solar-powered generators, showers, water equipment, batteries, etc.
But have we ever thought of using solarization for garden beds?
What is Solarization?
Solarization is a great technique that has been used for garden beds for many centuries.
It’s one of the commonly spoken topics for farmers, gardeners, and crop producers around the world.
Farmers and other gardeners have to face crop destruction, a decrease in production, yield, and a lot more.
Besides, farmers face the problems of unwanted growth of pathogens, weeds, pests, and bacterias like fungi, nematodes.
These are a big issue as their crop production and yielding decrease with this problem.
They even face crop failures, and sometimes their production becomes almost zero.
But not anymore because they have an eco-friendly, non-chemical solution.
That solution is called soil polarization.
We will inform you about how to solarize garden beds, the procedure, principles, and many more.
But before getting into the methods for solarizing a garden bed, let’s know more about solarization, its importance, its uses, etc.
You must have a little knowledge about what soil solarization is to use it efficiently.
Solarization is a non-chemical simple process that has been brought about to control soil-borne pests and to kill or destroy bacteria, pests, and insects from the soil using natural solar radiation.
What Are the Benefits of Soil Solarization?
Farmers use the process to improve soil efficiency.
Now, we can also utilize it in various fields like generating electricity, gardening, and various other fields.
Have you guys ever thought of how farmers kept their crops pests free in ancient times?
I know that you have not thought of this as no one thinks about it.
So, the answer is this.
They use the solarization process to protect their crops.
In ancient times, when there were no advanced pesticides or insecticides, farmers used this non-chemical, eco-friendly technique for controlling pests to raise soil temperatures to a particular level.
In this way, the pathogens or insects would be killed by the warmth of the soil.
Some people think that solarization was first initiated in India, but no.
The technique was first developed or reported in 1888 in Germany.
This was professionally and legally used in the United States of America in 1897.
We also call the process decontamination of soil by the use of sunlight.
Soil Solarization is the third suitable approach for soil improvement.
The other two approaches which we often use are soil fumigation and soil steaming.
Earlier it was depicted or discovered as a productive and effective method for improvement or protection of soil from pests or weeds.
The process does not leave any chemical residue and is an appropriate method for home gardeners or farmers.
Seasonal soil temperatures, fertilization during raised temperature, soil irradiation, time, and moisture are popular disinfection methods, with lethal agents being the sun rays/radiation or heat.
Solarization, or solar heating optimization of soil, increases the presence of beneficial soil organisms which combat all kinds of conditions in the following seasons.
It generally works by raising the soil temperatures to a particular level for the desired time frame, so that it can kill weeds, insects, and pests in the soil.
It’s important to ensure that the soil is maintained and is prepared for the process.
The soil must be kept covered as the thermal treatment requires moist soil.
The solarization process is helpful and very effective in all types of soils or gardens, from flowers to vegetables and also in the raised garden beds.
The process can make the soil more healthy and pesticide-free by adding organic materials like composts and crop residues before beginning the process of solarization.
The process to solarize a garden bed can be made by covering the ground with a piece of polyethylene or net trap so that the sun heats it to the highest soil temperature.
The soil will now be hot enough to kill pests.
This method is used to prepare the soil or bed for the next planting season.
What is the Difference Between Artificial Heating and Soil Solarization?
People sometimes consider artificial heating and solarization as the same process because of a lack of knowledge.
They get confused as both have soil heating as the essential component.
But in solarization, the heat is directly transferred to the soil in the plastic box or open field without the use of any source.
Artificial heating involves a source to transfer the heat to the soil surface and converts the heat into an artificial one.
Natural solarization provides mild soil temperature, while the artificial solarization process consists of heat carried out through a source of about 70-100 degrees Celsius.
However, the use of sun rays also requires some processes, methods, and guidelines for better killing/removal of pests and insects.
These processes will be discussed ahead in the article.
Now, let’s go to the importance of why we should use solarization as a process for garden beds or soil.
What is the Importance of Solarization?
Solarization is an essential method in today’s life.
It’s beneficial and important for farmers, gardeners, crop producers, and various other industrialists.
Nowadays, for farmers and gardeners, it has become a challenge to control the growth of weed seeds, pests, and pathogens like parasitic nematodes, fungi, etc.
All these grow inside the soil causing damage to crop production and food quality.
Pesticides and other soil fumigants are not that effective in reducing the pathogens as they leave many of them intact.
However, solarization makes it easier and possible for farmers to protect their soil and crops from harmful pathogens and bacterias.
- Solarization is a method that raises soil temperature to a level that destroys disease-causing organisms such as parasitize plant pathogens and kill weed seeds, pests, and insects.
- It’s used as a pest and weed control technique that also improves soil health by advancing the nitrogen content and nutrients to the growing crops.
- This method also decomposes or speeds up soil organic materials breakdown and releases soluble components/nutrients like nitrogen, magnesium, calcium, fulvic acid, and potassium for the plant’s growth.
- Solarization allows plants to grow faster with better quality yields.
- It also helps in building beneficial microorganisms in higher proportions.
- It creates and develops pure soil for the next crop planting.
Now, what are the advantages we gain after solarization?
So here, we will discuss the advantages of Solarization.
What Are the Advantages of Soil Solarization?
Soil solarization has its importance and is also beneficial and advantageous in a bacterial and eco-friendly manner.
The Two Main Advantages of Solarization
- The solarization process contains minimal drastic side effects on the abiotic and biotic components of the soil, making it more effective.
- Also, it’s suitable for developed, underdeveloped, and non-developed countries as it’s affordable and less expensive than the chemical or artificial soil heating/disinfestation process.
Other Advantages of Solarization
- It destroys or controls unwanted fungal and bacterial plant pathogens that cause Fusarium Wilt, Phytophthora root rot, Southern Blight, Verticillium wilt, Damping-off, Tomato Canker, and many others.
- Solarization also reduces several species of nematodes that are poisonous and can even recolonize the soil by moving deeper to escape the heat.
- It controls weed seeds production in the soil with its high solar radiation.
- The solarized soil produces better and healthy quality food with no insects in it.
- It also increases food availability as the soil can produce food, fruits, or vegetables in more quantity.
As we have discussed a little about solarization and its importance, let’s move on to its limitations.
What Are the Limitations of Solarization?
Like other processes, soil solarization also has some limitations.
- Its dependence on climatic conditions or climatic change is its limitation as it has solar radiation as its main source of destroying organisms.
- Another is the pollution caused by the remaining clear plastic residue used during solarization.
- The last limitation demands soil to remain clean and crop-free for a few days or weeks.
Principles of Solarizing a Garden Bed
There are some principles to remember to maximize the benefits of solarization.
- The solarization process heats the soil with a recurring daily cycle.
- The efficiency of heat temperature decreases with the increase in soil depth.
- Fertilization of soil can be done anytime, but the best time considered for this process is when the conditions are favorable and can be determined by measuring soil temperature or by tarping.
- To increase the thermal sensitivity of desired organisms, to advance the conduction of heat, and to enhance the biological activities during the process, proper moisturization in the soil is necessary.
- Moistening of soil can be done by irrigating it a single time before applying the clear plastic.
- Additional irrigation should be avoided and is not necessary as it may interrupt the process and can be carried out during nighttime.
- Preparation of the soil is necessary before solarization so that after the process, the soil should not be disturbed.
- Thin and clear polyethylene is used to trap the soil.
- The process causes physical, chemical, organic, and biological changes in the soil that can eliminate pests, enhance plant growth and yield.
What is the Solarization Process?
Now let’s understand how to solarize garden beds and increase heat absorption.
So, the best time to perform the process is when the solar radiation or temperature is at its highest.
This occurs during a long day with a clear sky, minimal wind flow, and higher air temperature.
Things to do:
- The soil should be leveled and must be debris/waste-free.
- Moist soil is best to raise soil temperatures, but the soil should not be saturated.
- A trench should be integrated before applying or trapping the soil with thin plastic.
- Don’t remove the plastic and let it remain as it’s for about four to six weeks for better heat retention.
1. Preparation of Soil
As in any process, before evolving anything, we need preparation for it.
Before soil solarization, we need to take the initial step, which is the cleaning of the soil surface.
The preparation of the soil is done so the clear plastic sheet can be easily fixed on the smooth and clean soil bed and will not produce air pockets.
If we do not avoid air pockets, they can reduce the heat absorption of the soil, and the clear plastic can even be blown away.
Soil solarization can be best performed on flat areas as they can absorb the best amount of heat.
Raised or leveled beds are also considered as these can protect the particular soil area from getting recolonized by weed seeds.
Consider laying beds from North to South rather than going from East to West to improve the consistency of heating radiation.
The best soil solarization occurs in areas with a minimal slope.
So raise the garden bed, maintaining minimal slope or level.
2. Irrigation of Soil
Irrigate the soil to a depth of at least 12 inches.
It will be easier if you irrigate the soil with solar pumps before trapping the garden bed with thin plastic.
You may irrigate the soil with a soaker hose after covering the soil bed with a net or clear plastic.
Just irrigate the soil and place clear and thin plastic, just after it to avoid or reduce the evaporation of water.
It will help in maintaining the moisture of the soil throughout the process of solarization.
Avoid irrigation during the process, as it may interrupt the process and the soil will not absorb the required amount of heat.
The process depends on the soil’s moisture condition.
Therefore, ensure that the moisture is high, so it will absorb the heat radiation.
3. Choosing of Plastic Tarp
For solarization, always use a clear and transparent plastic sheet so the radiation of the sun can easily pass through it, and the soil can easily trap the heat.
Black plastic sheets are not that effective as they will absorb the heat.
Therefore, the heat will not reach deep into the soil.
Choose black/dark or opaque plastic sheets while performing soil solarization in coastal regions.
Choose a thin plastic with an approximate thickness of 0.001 inches.
Otherwise, it can get torn with the pressure of the wind.
In the higher wind pressure areas, minimal thicker plastic with 0.0015-inch thickness is better and for a small treated area prefer 0.004 inches thick plastic sheet.
Many types of plastic designed for the process won’t get torn by the wind, any animal, or by the sunlight.
You can easily access plastic sheets from hardware shops.
Select a clear and transparent film.
It should not be made of cloudy, milky, or translucent material.
Otherwise, it will repulse heat radiation.
Check the plastic sheets carefully, so that they can be removed easily at the time of disposal.
While performing a longer solarization process, prefer covering small areas with fresh and new plastic sheets.
In case the plastics get torn, then cover the holes with some durable tapes.
For home gardens, use a double plastic layer creating an air space with a plastic bottle or PVC pipe to raise the soil temperature.
4. Place the Plastic Over the Garden Bed
On flatbeds, prefer placing the plastic tightly around the area to be solarized by digging a trench of about 4-6 inches.
Put one edge in the trench and cover it with the soil to hold the plastic.
Pull the other side of the plastic tightly and again cover it with soil from the other side of the trench.
Do the same with the plastic around for all the sides.
Pack the plastic closer to the surface of the area for better absorption of heat in raised beds and normal surfaces.
Avoid covering multiple beds with single plastic.
Otherwise, it will reduce the heat absorption, and the high winds will tear the plastic.
Prefer using single plastic to cover a single bed, as it allows proper absorption of heat without letting it waste on the channels between the beds.
Use a plastic tarp with a larger surface area to cover the entire bed, and some extra areas must be left to dig in the trench.
Maintain a proper distance between the two beds and avoid the merging of the treated soil with untreated soil. otherwise, the treated soil will again get infected
5. What Happens During the Soil Solarization Process?
During soil solarization, the soil needs both time and temperature conditions for effective results.
If the soil temperature is not increasing, then don’t remove the plastic and let it stay on the soil until the temperature rises.
Maintain a temperature of 110 to 125 degrees Fahrenheit on the top 6-8 inches of soil daily.
Prefer using temperature probes or soil thermometers to verify the soil temperatures daily.
Approximately four to six weeks of heat absorption is sufficient during the warm days to control the pests and annual and perennial weeds.
On winter and cloudy days, don’t remove the plastic from the garden bed for about 8-10 weeks as it’s difficult to destroy the pests in such weather conditions.
Similarly, on the hottest days, pests can be destroyed soon or even before six weeks.
Don’t interrupt or disturb the plastic in between the process.
6. After Solarization
After the completion of the process, remove the plastic.
Keep in mind not to displace or disturb the soil.
Take care not to bring them to the treated soil area.
Don’t disturb the plastic as it remains as compost, and plants can be planted through it.
Paint the transparent plastic sheets with white or silver color to repel pests and insects.
The soil’s plastic tarp gets degraded during the growing season.
If you want to cultivate the soil before planting the seeds, then it must be about 2 inches deep to avoid the underneath weeds rising the treated surface.
After accomplishing your procedure, you will see a reduction in weeds, pests, and other soil pathogens for the next four to five months.
The period is long enough for the growth of the fall garden.
But keep in mind, as solarization destroys the soil-borne pathogens, they also can recolonize in the solarized soil.
So you have to protect and take good care of the soil from time to time.
As you all have gone through the procedure of solarizing a garden bed, I hope you all liked it.
This blog has covered all the points on how to solarize a garden bed.
Whether you’re a farmer or a home gardener, with the above discussion, you all will be able to improve your soil’s condition and protect them from pests using this affordable environment-friendly method.
Many people across the globe prefer soil solarization, and in fact, farmers use this method for improving their soil conditions.
Even agriculture professionals and scientists have also declared soil solarization as the best technique to be used for garden beds for better crop production.
Now, apart from farmers, even home gardeners prefer this process for garden soil to reduce the production of weeds and pathogens.
We hope you’ve enjoyed and found useful this guide on how to solarize a garden bed. If you know of anything that we’ve left out, please let us know in the comments below.