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Covering Plants with Plastic Bottles: The Benefits Explained

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Why should a plant be covered? Covering plants with plastic bottles will protect them from external elements unfavorable to their health.

Plastic bottles are commonly used to cover plants because they protect from pests, disease, excessive moisture, and even frost. When a plant is covered, it should still be provided with adequate water, light, and fertilizer to continue growing healthy.

However, covering a plant can pose some risks which we will discuss further in this article as well as the things to consider that will mitigate any potential risk.

Can a Plant Survive within a Plastic Bottle?

Covering Plants with Bottles

A plant can survive under a plastic bottle because it creates an environment similar to that of a terrarium where the humidity and temperature as well as the nutrients are contained and recycled.

If such conditions are held constant, meaning that there are no openings, the plant will be able to survive for a long time. The actual amount of time to plant may survive depends on the internal conditions.

A plant that is placed under a clear or opaque plastic bottle will be able to survive longer due to the fact that it will be able to receive light or sunlight in addition to the nutrients within the confines of the container.

For this reason, black or very dark-colored bottles should not be used if the intention is to keep the plant under the bottle for an extended time.

The Reasons for Covering Plants

Protect Plants Against Frost

Frost is caused by cold temperatures which cause water vapor to condense into tiny ice crystals. These crystals then fall onto the surface of the plant causing damage.

Even if the plant is kept indoors, the temperature can drop below freezing. If the temperature drops too low, the plant will freeze.

Plastic bottles can protect plants against frost by providing the right temperature and humidity for the plant to survive despite the abnormally or colder environmental conditions.

The main conditions at play are humidity and heat. The plastic bottle will keep the air within it warm but not hot enough to burn the plant. It also keeps the air humid so that there is less evaporation from the leaves and stems.

This means you do not need to worry about watering your plants too often when they are covered with plastic bottles. They will be able to absorb moisture through their roots and stems as needed.

Protects Against Pests and Diseases

Plants are often covered to protect against pests and diseases. When there is a known pest or disease that is invading or attacking a crop or plant, adjacent plants are protected by covering the infected crop with some plastic or fabric.

It is important to know that these materials are not impervious to insects and diseases. However, they help to contain them and prevent them from spreading to other crops.

They also help to control the growth of weeds and grasses around the area. This helps to keep the soil healthy and free of competing plants.

Protects From Insects

Insects are sometimes found in large numbers near crops. For example, aphids and mealybugs often infest gardens and vineyards.

These insects feed off of the plant’s sap and leave behind sticky honeydew. This causes the plant to become weak and eventually die.

To prevent this, many farmers use insecticides to kill both the bugs and the plant. Other times, the farmer covers the plant with a material that repels the insects.

Protects Against Too Much Rain

If there is a plant or crop that is not well suited to wetter conditions covering both the plant and the soil may become necessary in order to protect it from the effects of overwatering.

A few examples include strawberries and tomatoes. Both of these fruits require a certain amount of rainfall to grow properly.

However, if there is a lot of rain, the soil becomes saturated and the plant cannot take up any more water. 

In this case, it is necessary to cover the plant with something that will allow it to absorb rainfall while keeping out excess water.

What Happens When You Cover a Plant With a Plastic Bottle?

Plant inside a bottle

You have probably seen people cover their houseplants and seedlings with plastic bottles before. This is done because some plants require more protection than leaving them to withstand the elements.

Placing the plant or seedlings under a plastic bottle is a great way to protect it from extreme weather conditions. However, it is important to note that some plants cannot withstand being confined.

The water within the soil when evaporated does not get lost in the atmosphere. Instead, it is trapped within the confines of the plastic bottle and will condense as the temperature cools.

The plant then reuses this water either by absorption through the stomata or from the soil. It’s like a mini-ecosystem.

On the other hand, the temperature within the bag also remains fairly warmer than the outside environment simply because the process of transpiration produces heat that will not be totally lost to the atmosphere.

This does not mean that the plant will overheat, especially during colder periods; it means that the temperature will be relatively warmer and easier for the plant to cope with.

Some plants, like cacti or succulents, do not tolerate being put into confined spaces. In these cases, you should use other methods of keeping the plant safe, like relocating them to safer places.

Using a Plastic Bottle Greenhouse

You might want to repurpose your plastic bottles into something else. You can create a greenhouse using these plastic bottles. 

The greenhouse will allow plants perfectly fine while protecting them from whatever harsh environment they are being protected from.

Generally, this can be high winds, heavy rains, and frost. An added benefit of using a plastic bottle greenhouse is that it protects the plants against pests as the environment can be totally controlled.

How to Cover a Plant or Seedling With a Plastic Bottle

To cover a plant with a plastic bottle, there are a few steps that would ensure that it is done correctly.

  1. Find a suitable place where the plant has adequate light. A relatively sunny spot is ideal.
  2. Measure the size of the plant with its canopy and locate a suitable size bottle that will not bend or break any of the leaves.
  3. Cut off the bottom of the bottle because this is where the largest opening is.
  4. Gently place the bottle over the plant, making sure to tuck in leaves into the bottle.
  5. The bottle should rest on the soil and be inserted into the soil.
  6. Make sure to remove the plastic bottle after two weeks to prevent mold growth.

Things to Do Before Covering the Plant with Plastic

Water the Plant

Don’t forget to water the plant first. If you don’t, the plant may die. It is best not to wait until the soil dries out before watering and covering it with a plastic bottle.

By adding the usual amount of water, the plant is accustomed to the enclosed environment and will tend to hold and recycle that water through evaporation, transpiration, and condensation.

Fertilize lightly

Before a plastic cover is applied, you should apply a slow-release fertilizer to the top of the soil or even mix it in. This will feed your plant for the duration of which it has to remain in the plastic bottle “greenhouse.”

Position the plant

When covering a plant, make sure that the plant is positioned correctly. This is important because having the plant in an area that is too shady can cause it to suffer from a lack of sunlight or even become leggy.

You may also have to move the plant depending on how big it is.

Also, watch out for any sharp objects that could puncture the bag.

What plants need to be covered in winter?

  • Seedlings
  • Cactus
  • Herbs
  • Vegetables
  • Ornamental grasses
  • Container plants
  • Young Plants

Reasons why you Should Not cover plants with plastic garbage bottles

Lack of Light

Plants use sunlight to make food for themselves through photosynthesis. To grow, plants need access to light from the sun.

Plastic bottles that are very dark will block that much-needed light the plants need to create food.

It is recommended that clear or opaque material is used to provide adequate light for the plants while it is covered.

Lack of Air Circulation

Air circulation is essential for a plant because it promotes water evaporation, and transpiration prevents condensation on the leaf surfaces, reduces the growth of fungal infections and rot, and helps make their growth stronger.

However, if the plant is healthy and there is no air input into or out of the cover, then the risk of a fungal infection may be very limited.

What Happens When You Cover a Plant?

When a plant is covered with a bottle, it creates a mini-ecosystem where the plant produces food and waste gases, which is then reused by the plant within the bag.

The ecosystem is also dependent on the plant being in healthy soil and the microorganisms that contribute to the soil’s health.

The potential of Overheating the Plant

Plants that are covered do risk the potential of overheating, which is why it is recommended they be placed in areas where there is enough sunlight,  but not too much,for the plant to thrive.

Too much light or too much shade can cause the plant to overheat or even become leggy due to the lack of light.

Plastic Bottles That Can be Used to Cover plants

There are various types and sizes of plastic bottles available, each designed for different purposes and applications. 

Here are some common types and sizes:

Water Bottles: 

These are typically available in sizes ranging from 8 ounces (240 ml) to 1 gallon (3.8 liters). They come in different shapes, including cylindrical, slim, and collapsible.

Beverage Bottles: 

These are used for carbonated drinks, juices, energy drinks, and other beverages. Sizes vary from 8 ounces (240 ml) to 2 liters.

Milk Bottles: 

Commonly used for packaging milk and other dairy products. Sizes range from 8 ounces (240 ml) to 1 gallon (3.8 liters). They are often rectangular or square in shape.

Household Cleaning Bottles: 

These are used for packaging cleaning solutions, detergents, and other household chemicals. Sizes range from 8 ounces (240 ml) to 1 gallon (3.8 liters) or more.

Note: The sizes mentioned above are approximate and can vary depending on the manufacturer and specific product requirements.

Other Types of Covers to Use

Grocery Gags

This is the cheapest and most environmentally friendly option as the bottles can easily be accessed and reused. A clear, white, or even opaque-colored bag can be used to protect against any degree of frost.


The plant cover is made of high-quality polypropylene fiber fabric with anti-ultraviolet function, good air permeability, high strength, and low fluff. It can be repeatedly used with proper care.

Fabric Bags

Fabrics not only allow air and water to enter the plant but also protect plants from UV rays and other animals. It is the perfect choice for plants to prevent frost, freezing, and animal violation in winter.

Garbage Bags

Garbage bottles can cover plants but not for an extended time, depending on the color. This is mainly because most garbage bottles come in black or white.

With white bottles, plants can be covered for a longer period of time than if a black bag is used.

Other Methods of Keeping Your Plants Safe

There are many ways to keep your plants safe during inclement weather. For example, you could place them in a terrarium, grow them indoors, or even move them to a different location.

However, there are certain things that you must consider when deciding how to protect your plants best.

First, you want to make sure that the plants are healthy. You should look at the roots and check for any signs of rot or disease.

Next, you want to make certain that the plants are receiving adequate sunlight. Make sure that the area where the plant is located receives direct sunlight or some degree of sunlight that will sustain the plant.

Finally, you want to make absolutely certain that the environment where the plant is located is protected from weather conditions such as high winds, heavy rain, and frost.

If you follow these three steps, you should be able to protect your plants from the elements without having to resort to using plastic bottles.

See our detailed article on safe places to keep plants at home.

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