When it comes to growing plants, the covering you choose is crucial. That’s why – in this article I want to talk about when to use clear plastic for a greenhouse so that you know all the ins and outs of keeping your plants warm with it.

Keep reading to discover more.

The Pros And Cons Of Using Clear Plastic For A Greenhouse

But first – what are the positives and negatives of clear plastic?

The Pros:

Here are some of the biggest benefits you can expect when using clear plastic for greenhouse:

Light Penetration:	Clear plastic lets in tons of natural sunlight (80-90%), which is awesome for your plants. They get all the light they need to grow healthy and strong.
Cost-Effective:	Compared to glass, clear plastic is usually much cheaper. This makes it an affordable option for building a greenhouse, especially if you’re on a budget.
Durability:	Clear plastic is quite durable and can withstand various weather conditions. Many types are UV-resistant, which means they won’t degrade quickly when exposed to sunlight, lasting several years.
Flexibility:	You can easily cut and shape clear plastic to fit any greenhouse size or design. This flexibility is perfect for DIY projects, allowing you to customize your greenhouse as needed.
Safety:	If clear plastic breaks, it doesn’t shatter into dangerous shards like glass. This makes it a safer option, especially if you have kids or pets around.
Heat Retention:	The plastic material helps to trap heat inside the greenhouse, maintaining a warm environment (1) even during cooler nights or early spring days. This consistent warmth supports better plant growth.

So those are all awesome, right? But what are the downsides?

The Cons:

Durability Issues:	While clear plastic is generally durable, it can still be prone to wear and tear over time. It can get scratched or torn by strong winds, hail, or debris, potentially reducing its lifespan compared to glass.
UV Degradation	Even though many clear plastics are UV-resistant, they can still degrade over time due to prolonged exposure to sunlight. This can lead to yellowing or brittleness, reducing the amount of light that penetrates and making the plastic less effective.
Condensation:	Plastic can be prone to condensation, which can create a humid environment that fosters mold and mildew growth. This can affect plant health and require additional ventilation management.
They Can Look Ugly:	Clear plastic often doesn’t look as nice as glass. It can appear cloudy or dirty more quickly, which can detract from the overall appearance of your greenhouse.
Replacement Frequency:	Clear plastic typically needs to be replaced more frequently than glass. Depending on the quality, it might last only a few years before needing replacement, adding to long-term costs and maintenance.

Now that you know the different pros and cons of clear plastic for greenhouse. Let’s talk about when you should be use it.

When Clear Plastic Is The Best Option

Clear plastic is best for colder climates, starting seeds and early season growth, as well as for plants that require full sunlight. It also works well in areas with pests or rodents.

In Colder Climates

In colder climates, clear plastic is an ideal choice for a greenhouse due to its light transmission properties. This assists in maximizing sunlight exposure, creating a warm environment conducive to plant growth.

The UV protection provided by the plastic helps maintain stable temperatures within the greenhouse and ensures that plants receive ample sunlight even during the winter months.

To ensure efficient plant growth in colder climates, growers can rely on the benefits of using clear plastic in their greenhouses. This material plays a crucial role in providing optimal conditions for cultivating various types of crops throughout the year.

For Starting Seeds & Early Season Growth

To provide the best conditions for starting seeds and early season growth, clear plastic is an ideal choice due to its light transmission and UV protection. This type of greenhouse plastic helps create a warm and humid environment essential for germination, ensuring that seedlings receive adequate sunlight to support healthy growth.

The light diffusion properties also help prevent scorching of delicate young plants while maintaining optimal growing temperatures within the greenhouse. Furthermore, transparent greenhouse coverings allow growers to closely monitor plant health and progress without compromising on protection from pests or rodents.

Here’s how to germinate seeds quickly: Best Seed Starter Greenhouse Kits To Germinate Your Seeds Fast

For Plants That Require Full Sunlight

Here are some examples of plants that love full sunlight:

• Tomatoes – These popular garden vegetables need at least 6-8 hours of full sunlight daily to produce healthy, flavorful fruits.
• Peppers – Both sweet and hot pepper varieties require full sunlight to grow properly and develop their flavors.
• Cucumbers – These vining plants need plenty of sunlight to produce crisp and juicy cucumbers.
• Squash – Summer and winter squash varieties thrive in full sunlight, needing 6-8 hours of direct light each day.
• Corn – This tall-growing crop requires full sunlight to produce healthy ears of corn.
• Lavender – This aromatic herb needs full sunlight to grow well and produce its fragrant flowers and foliage.
• Basil – This popular culinary herb requires plenty of sunlight to grow lush and flavorful leaves.
• Roses – Most rose varieties need full sunlight to produce abundant and healthy blooms.
• Marigolds – These bright flowers thrive in full sunlight and are often used in gardens for their pest-repellent properties.

In Areas with Pests or Rodents

In regions where pests or rodents are a concern, using clear plastic as a greenhouse covering can be an effective way to create a barrier between your plants and unwanted visitors, shielding them from harm without compromising access to essential sunlight and air.

What Are The Best Clear Plastic Options On The Market?

Recommendation 1: Inslat Clear Plastic For A Greenhouse

This 6 mil greenhouse plastic film is 12′ x 25′ and made from strong, tear-resistant polyethylene. It’s UV resistant and built to last up to four years, creating an ideal environment for your greenhouse. The plastic allows light to pass through evenly, helping your plants grow better. It has anti-aging and anti-drip features to prevent harmful drips and reduce dust buildup, which is great for plant health.

The film is easy to install and can be cut to different sizes to fit various needs, like grow tunnels or mini greenhouses. It’s designed to withstand extreme weather, including heat, heavy rain, frost, and strong winds, and can also be used to cover furniture and appliances to keep them dust-free.

Check Best Price ➡️ Amazon

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Recommendation 2: Grelwt Clear Plastic For Greenhouse

This 12×25 ft, 6 mil greenhouse plastic sheeting is a durable replacement cover with a three-year lifespan. Made with five-layer technology, it’s strong and flexible, and allows 90% of light to pass through, essential for plant growth. The film includes an anti-drip feature that prevents water droplets from falling on plants, which helps avoid plant burning and reduces the risk of pests and diseases.

While the plastic may look a bit hazy, it’s designed to protect your plants. This versatile sheeting can be used to cover grow tunnels, mini greenhouses, and gardens, perfect for vegetables, flowers, fruits, and herbs. It’s also UV resistant, ensuring long-lasting protection for your plants.

Check Best Price ➡️ Amazon

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When Clear Plastic May Not Be The Best Choice

Clear plastic may not be the ideal choice in hot and sunny climates, for plants that require more shade, and in areas with high winds.

In Hot and Sunny Climates

Hot and sunny climates require careful consideration when choosing greenhouse coverings. Clear plastic may not be ideal in these conditions as it can create excessive heat buildup, potentially harming plants.

Greenhouse growers in such areas may benefit from using materials that provide more shade or UV protection to maintain a suitable growing environment for their plants, addressing the challenges posed by intense sunlight.

Moving into the next section about “For plants that require more shade,” let’s explore how different plant types have specific needs when it comes to light exposure.

For Plants That Require More Shade

In addition to providing optimal light diffusion, clear plastic sheeting also offers protection from outdoor elements, helping to maintain a consistent climate within the greenhouse.

This is particularly beneficial for plants that require a more stable and shaded environment for their growth and overall well-being.

Here are some examples of plants that want some shade:

• Ferns – Plants like Boston ferns and maidenhair ferns do great in the shade and look nice in gardens and indoors.
• Pansies – These popular garden flowers can tolerate some shade and are known for their colorful, face-like blooms.
• English Ivy – Hardy vine that grows well in the shade. Good for ground cover or climbing walls and fences.
• Violets – Small, pretty flowers that do well in the shade. Great for adding a delicate touch to garden beds and borders.
• Lily of the Valley – Small plants with sweet-smelling, bell-shaped flowers that grow well in cool, shady spots.

In Areas With High Winds

In contrast to plants that require more shade, clear plastic may not be the ideal choice in areas with high winds. Strong gusts can cause the plastic to tear or become damaged, compromising its ability to provide a stable environment for plant growth.

Greenhouse growers in these windy regions may benefit from using a more durable material such as reinforced greenhouse cover or thicker plastic sheeting, which can better withstand the impact of strong winds without comprising the growing area’s protection and stability.

What Are Some Good Alternatives To Clear Plastic?

Here is a good video to watch on this topic:

Conclusion

Choosing clear plastic for your greenhouse can be a great option, especially in colder climates, for starting seeds, and for plants that need full sunlight. It’s affordable, durable, and allows lots of light to get through. However, it might not be the best choice in very hot climates, for plants that need more shade, or in areas with high winds.

Remember to consider your specific needs and local conditions when picking the right cover for your greenhouse. For reliable options, you might want to check out the Inslat and Grelwt clear plastic films on Amazon—they’re both UV resistant, durable, and designed to promote healthy plant growth. Happy gardening!

FAQs

Can I use clear plastic for a greenhouse in all seasons?

Yes, clear plastic is suitable for year-round use as it provides ample light and helps retain heat during colder months.

How do I know if clear plastic is the right choice for my greenhouse?

If you want maximum light transmission and warmth for your plants, then clear plastic is an excellent choice.

Is clear plastic more effective than other materials for a greenhouse?

Clear plastic is highly effective due to its ability to allow sunlight through while trapping heat, creating an optimal growing environment.

Is green or clear plastic better for a greenhouse?

Clear plastic is better because it allows more sunlight (80-90%), which is essential for plant growth. Green plastic filters out more light, which isn’t ideal for all plants.

What type of plastic is best for greenhouses?

Polyethylene (PE) film is best. It’s durable, flexible, and cost-effective. UV-resistant PE lasts longer and some types have anti-drip features to prevent water droplets inside.

What thickness of plastic is best for a greenhouse?

6 mil (0.006 inches) thickness is ideal. It’s durable enough to withstand weather conditions yet flexible and easy to handle. Thicker plastics are more durable but harder to work with and costlier.

References:
1 – BONNIE L. GRANT, Greenhouse Humidity Info – Is Greenhouse Humidity Important, taken from: https://www.gardeningknowhow.com/special/greenhouses/is-greenhouse-humidity-important.htm