Are you struggling to extend your growing season or protect your beloved plants from frost damage? A cold frame greenhouse, often compared to a mini, low-level version of a full-size greenhouse, could be the ideal solution.

This DIY guide will walk you through the process of building a cost-effective cold frame that traps solar heat and creates an optimal environment for plant growth.

Ready to cultivate like never before? Let’s dig in! 🌱

What is a Cold Frame Greenhouse?

But let’s get a little bit more technical…

Definition and purpose

A cold frame greenhouse is a unique structure designed to favor plant growth. It functions as a miniature greenhouse, using various materials for its construction. The purpose of this structure is to harness solar energy, creating a warm environment ideal for plants’ development.

Cold frame greenhouses employ natural sunlight, which penetrates through their sloped lids and warms up the interior while preventing heat from escaping. This technique allows gardeners to extend the growing season and provide protection against frost for delicate plants.

Having a southward orientation ensures optimal exposure to sunlight while shielding it from dominant winds further underscores its efficiency in purposeful gardening use.

Benefits of using one

Leveraging a cold frame greenhouse in your garden offers a host of impressive benefits:

• Extends the growing season: Cold frame gardening lets you start planting earlier in spring and continue harvesting deep into fall. It can even foster winter growth for hardy plants.
  
• Protects plants from harsh conditions: Your fragile plants are safeguarded against frost, heavy rain, strong winds, and pests when inside the cold frame.
  
• Conserves resources: The natural sunlight heats up your DIY greenhouse without extra energy costs, making it an eco-friendly option.
  

And we’re not even close to being done with these benefits…

• Enhances plant growth: The warmth and protection provided by a cold frame promote quicker germination and healthier plant development.
  
• Offers versatility: You can adjust your cold frame greenhouse design to fit any space in your backyard.
  
• Supports various types of plants: From lettuce to flowering bulbs, diverse plant species enjoy the controlled environment of a cold frame.
  
• Promotes efficient use of space: With careful planning, your homemade greenhouse helps maximize available garden area for increased crop yield.
  
• Enables better control over growing conditions: Cold frames allow you to manipulate factors like temperature and humidity more effectively than open-air beds.

Types of plants that thrive in a cold frame

A variety of plants can thrive in a cold frame greenhouse, enhancing the versatility and efficiency of your backyard garden.

When planning your growing season, remember that cold frames don’t provide an additional heat source to keep your plants warm in the frigid months

Here are some great plants based on the season to grow in an unheated greenhouse.

SEASON	PLANTS
Early Spring (Feb – April)	Broccoli Cauliflower Kale Radishes Cabbage Lettuce Scallions Spinach Arugula Chard
Late Spring (April – May)	Eggplant Celery Corn Peppers Melons Squash Pumpkins Beans Tomatoes Cantaloupe
Autumn	Lettuce Radishes Cabbage Cauliflower Spinach Kale
Winter	Leeks Parsley Arugula Spinach Lettuce

Why You Should Build a Cold Frame Greenhouse

Building a cold frame greenhouse is cost-effective, efficient, and provides control over growing conditions, resulting in increased crop yield and quality.

Cost-effective and efficient

Additionally, the design of a cold frame allows for maximum sunlight exposure and heat retention, ensuring that your plants receive the necessary warmth to thrive. With its affordability and effectiveness, building a cold frame greenhouse is an excellent choice for any gardening enthusiast looking to extend their growing season.

Adds control over growing conditions

A cold frame greenhouse adds control over growing conditions, allowing you to create the ideal environment for your plants. By building a cold frame, you can regulate factors like temperature and humidity, ensuring that your plants have the best possible chance of thriving.

The structure traps solar heat, keeping the interior warm even during colder months. Additionally, with proper insulation and ventilation, you can adjust airflow to prevent overheating or excessive moisture buildup.

This level of control enables you to extend the growing season and protect your plants from harsh weather conditions such as frost or strong winds.

Increases crop yield and quality

Building a cold frame greenhouse can significantly increase the yield and quality of your crops. By creating a controlled environment, you can optimize growing conditions to suit different plants.

With the ability to trap solar heat, cold frames provide warmth even in colder seasons, enabling plants to thrive and produce more abundant harvests. The natural sunlight and insulation help maintain consistent temperatures, promoting healthy growth and preventing damage from frost or extreme weather conditions.

With proper care and maintenance, your crops will flourish inside the cold frame greenhouse, resulting in higher yields and better-quality produce.

Still Want To Build A DIY Cold Frame Greenhouse?

We’re at that point in this guide where I ask you – “you still want to build this?”

There’s no shame in buying one that is already built, and I want to give you both of those options before we jump into the steps to building the greenhouse.

So if you’re looking to buy one then these are some good options for all budgets.

Recommendation 1: Quictent Mini Portable Greenhouse

The Quictent Mini Portable Greenhouse is a cool, easy-to-set-up pop-up grow house that works both outside and inside. It’s pretty big, at 98 x 49 x 53 inches, and super user-friendly. Just stretch out the cover, pop in two folding fiberglass poles, and you’re all set. It’s made with eco-friendly stuff like a tough 600D oxford and clear PVC cover that keeps water out and protects your plants from too much sun. It’s sturdy too, with steel-wire rods and fiberglass poles.

This greenhouse comes with six stakes to keep it steady, especially when the weather gets rough. It has four big zippers so you can walk in easily, and these cool buckles keep the zippers in place. You can also tweak the sunlight and temperature inside with the two zip-up windows. The extra-long cover helps keep your plants snug and secure – just tuck it into the soil. It’s perfect if you’ve got a garden box or want to grow some flowers.

Check Price ➡️ Amazon

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Recommendation 2: Exaco Biostar 1500-NP

The Exaco Biostar 1500-NP Juwel Premium Cold Frame Mini Greenhouse is a top-notch choice for gardeners. Measuring 59 inches wide, 32 inches deep, and 20 inches high, it’s the perfect size for smaller spaces. What makes it really stand out is its solid construction using 8 mm twin-wall polycarbonate that’s great at keeping heat in, even when it’s super cold outside.

This mini greenhouse is designed with three roof windows for ventilation; one even has an automatic opener, and the other two have props to adjust their height. Inside, there’s a special no-drip coating that stops condensation from messing with your plants. It also comes with four corner stakes, making it stable and secure.

What’s really cool is how easy it is to put together and take apart – you can have it up or down in just 5 minutes, which is perfect for storing it away when you don’t need it. All in all, it’s a really high-quality product that’s ideal for keeping your plants happy and healthy.

Check Price ➡️ Amazon

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Recommendation 3: VegTrug Classic Cold Frame

The VegTrug Classic Greenhouse Frame and Multi-Cover Set is a super handy addition for anyone who’s into gardening all year round. It fits perfectly with the Medium Classic VegTrug planter, and its size is just right at 28″ x 70.7″ x 35.4″. It’s not just any greenhouse cover; this one’s all about extending your growing season and giving your garden a boost, even when it’s cold outside.

The frame is made from tough, powder-coated steel, so it’s going to last you a long time, no matter what the weather throws at it. This means your plants get a strong and stable home. The cover is where it gets really cool. It’s made from polyethylene with a micro-mesh layer, which is awesome for keeping those annoying insects away from your plants while letting them breathe and grow.

What’s also great is how easy it is to use. The cover has separate zippers for each layer and wide openings, making it a breeze to get to your plants and take care of them. This set is specifically designed for the Medium Classic VegTrug, so it’s a perfect fit and offers a complete solution for creating the ideal growing conditions for your plants.

Check Price ➡️ Amazon

Recommendation 4: Giantex Wood Cold Frame

The Giantex Wood Cold Frame Mini Garden Greenhouse is like a little gift from nature for your garden. Made from natural fir wood, it’s not only pretty to look at but also super strong and durable, holding up well against weather and wear. Plus, it’s been polished up nicely, so it’s smooth and free of any rough edges.

This mini greenhouse has a flip top lid that’s really handy. It keeps your plants safe from bad weather and other outdoor elements, and you can easily open it up to control the air flow inside. The tilted roof design is a smart touch too, preventing water from collecting on top. The roof is made of transparent PVC, which lets plenty of sunlight in to keep your plants happy, while also protecting them from wind and rain. The bottomless design of the greenhouse is great for drainage and makes sure your plants get all the nutrients they need from the soil.

It’s a good size too, measuring 39” x 19.5” x 14” (L x W x H), giving you lots of space for growing veggies, flowers, or herbs. Its rustic, simple style will look awesome on your balcony, backyard, deck, or terrace. Plus, it’s a champ at extending your growing seasons, protecting plants from the cold. Don’t worry about setting it up; it comes with clear instructions and everything you need for a quick and easy installation.

Check Price ➡️ Amazon

Steps to Building a DIY Cold Frame Greenhouse

To build a DIY cold frame greenhouse, start by choosing the right location, gathering materials, constructing the frame, adding insulation and covering, and optionally adding ventilation.

Here is an easy instructional video for you to follow:

Choose the right location

When building a cold frame greenhouse, one of the first steps is to choose the right location. It’s crucial to find a spot in your backyard that receives full sunlight throughout the day.

This ensures that your plants get enough light and warmth. Additionally, make sure the location is sheltered from prevailing winds to protect your plants from harsh weather conditions.

Remember, facing the frame towards the south will provide optimal sunlight exposure for maximum growth and productivity. By selecting an ideal location, you can create an environment that promotes healthy plant growth in your cold frame greenhouse.

Gather materials

To build your DIY cold frame greenhouse, you’ll need to gather the following materials:

Construct the frame

To build your DIY cold frame greenhouse, follow these steps:

1. Choose the right location: Find a spot in your backyard that receives full sunlight and is sheltered from strong winds.
   
2. Gather materials: You will need wooden battens, old windows or skylights, and a sheet of transparent material for the lid.
   
3. Start constructing the frame: Use the wooden battens to create a raised bed with sloped sides. Secure them together with screws or nails to form the foundation of your cold frame.
   
4. Add insulation and covering: Attach the old windows or skylights to the sloped sides of the frame to provide insulation and allow sunlight to enter. Place the transparent sheet on top as a lid.
   
5. Install shelves or shelving: Add optional shelves inside the cold frame to maximize space for growing plants.
   
6. Consider optional ventilation: To regulate temperature and air circulation, you can add vents or openings that can be opened or closed as needed.

Add insulation and covering

Insulate your cold frame greenhouse and provide adequate covering to create a warm and protected environment for your plants. Here’s how:

1. Line the interior walls of the frame with insulating material such as bubble wrap or polystyrene sheets.
   
2. Place a layer of reflective material, like aluminum foil, on the underside of the lid to maximize sunlight absorption.
   
3. Use clear plastic or polyethylene film as the covering for the lid to allow sunlight in while retaining heat.
   
4. Secure the covering tightly to prevent drafts and ensure optimal heat retention.
   
5. During colder months, consider using additional layers of insulation such as straw bales or blankets around the outside of the frame.
   
6. Monitor temperature regularly and adjust coverings accordingly to maintain ideal growing conditions.

Add shelves or shelving

To optimize the use of space and maximize plant growth, consider adding shelves or shelving inside your DIY cold frame greenhouse. By doing so, you can create additional levels for plants to thrive.

These shelves or shelving units can be made from wooden battens or recycled materials like old windows or skylights. Not only will this provide more room for your crops, but it will also help organize your plants and make them easier to care for.

Make sure to position the shelves in a way that still allows natural sunlight to reach all levels and ensure proper air circulation throughout the cold frame.

Here’s a detailed guide on greenhouse shelving: Everything You Need To Know About Choosing & Setting Up Greenhouse Shelving

Add optional ventilation

To ensure optimal air circulation and regulate temperature within your cold frame greenhouse, consider adding optional ventilation. This will help prevent issues like excessive humidity or overheating that can harm your plants.

By incorporating vents or windows into the design, you can easily control airflow and create a healthier growing environment. Proper ventilation also helps to reduce the risk of disease by minimizing stagnant air and promoting better plant growth.

Remember to strategically position these openings for maximum effectiveness, ensuring that fresh air reaches all areas of your cold frame while still maintaining its insulation properties.

In addition, having optional ventilation in your cold frame allows you to adjust the temperature inside based on fluctuating weather conditions. On warmer days, opening up the vents can release excess heat buildup.

You can also consider using fans for additional ventilation.

Here’s what you need to know about greenhouse fans The Secret to Perfect Greenhouse Temperatures – Boost Your Plants with a Greenhouse Fan

Tips for Maintaining and Using Your Cold Frame Greenhouse

Proper watering and temperature control are essential for maintaining a healthy cold frame greenhouse. Rotate your crops regularly to prevent disease and maximize productivity. Extend your growing season by using additional insulation and covering during colder months.

Proper watering and temperature control

To ensure the success of your plants in the cold frame greenhouse, it is important to practice proper watering and temperature control. Here are some tips to help you maintain optimal growing conditions:

Temperature Control:

• Check the temperature inside the cold frame regularly.
• Open the lid or provide ventilation on warm days to prevent overheating.
• Close the lid or add insulation during colder nights to retain heat.
• Use a thermometer inside for accurate monitoring and adjusting.

Implement Shading:

• Provide shade cloth or use light – colored coverings during hot summer months.
• This will help prevent excessive heat build-up inside the cold frame.

Here is a detailed guide on shading in your greenhouses: Greenhouse Shade Cloth 101: The Secrets to Rapid Plant Growth & Protection

Utilize passive heating:

• Place containers filled with water inside the cold frame.
• The water will absorb heat during the day and release it slowly at night, maintaining stable temperatures.

Here is more information around heaters along with recommendations: Discover the Ultimate Greenhouse Heaters for Year-Round Plant Protection

Rotating crops

Rotating crops is an important practice in cold frame gardening. It helps to maintain soil health and prevent the buildup of pests and diseases. Here are some tips for rotating crops:

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1. Plan your crop rotation schedule: Start by dividing your cold frame into different sections or beds. Assign each section a specific crop or plant family. Rotate the crops each year to a different section to prevent disease and nutrient depletion.
   
2. Follow a systematic pattern: Avoid planting the same crop or plant family in the same section year after year. Instead, move them to a different section following a specific pattern, such as clockwise or alternating rows.
   
3. Consider companion planting: Take advantage of companion planting principles when rotating crops in your cold frame greenhouse. Planting certain crops together can benefit their growth and help control pests and diseases naturally.
   
4. Practice good sanitation: After harvesting a crop, remove any remaining plant debris from the cold frame before planting new crops. This helps reduce the risk of pests and diseases lingering in the soil.
   
5. Pay attention to nutrient needs: Different plants have varying nutrient requirements. When rotating crops, consider the nutritional needs of each plant family and ensure that the soil is replenished with suitable organic matter or fertilizers.
   
6. Monitor for pest and disease patterns: By rotating crops, you can disrupt the life cycles of pests and diseases that may target specific plant families. Keep track of any recurring issues in certain sections so you can adjust your crop rotation plan accordingly.
   
7. Take advantage of cover cropping: In between growing seasons, consider planting cover crops in your cold frame greenhouse to improve soil fertility, minimize erosion, and suppress weeds.

Extending the growing season

Extending the growing season is a major advantage of using a cold frame greenhouse. With this structure, you can start planting earlier in the spring and keep your plants thriving well into the fall.

The trapped heat inside the cold frame creates a microclimate that protects plants from frost and extends their growth period. This means you can enjoy fresh produce for longer periods of time, even when temperatures drop outside.

By utilizing a cold frame to extend your growing season, you’ll be able to maximize your harvest and enjoy homegrown vegetables throughout the year.

Conclusion: Enjoy the Benefits of Your Cold Frame Greenhouse

Now that you know how to build a cold frame greenhouse, it’s time to enjoy the benefits! By constructing your own DIY cold frame, you can extend your growing season, protect your plants from frost, and increase crop yield and quality.

Get started on building your own cold frame greenhouse today and reap the rewards of fresh produce all year round.

FAQs

What materials do I need to build a cold frame greenhouse?

To build a cold frame greenhouse, you will need basic materials such as wooden boards, transparent plastic or glass panels, screws, hinges, and a latch for the door.

How long does it take to build a cold frame greenhouse?

The time it takes to build a cold frame greenhouse can vary depending on your skill level and the complexity of the design. Generally, it can take anywhere from a few hours to a couple of days.

Can I use recycled materials for building a cold frame greenhouse?

Yes, you can use recycled materials for building a cold frame greenhouse. This not only helps reduce waste but also makes it an affordable option.

How much does it cost to build a cold frame greenhouse?

The cost of building a cold frame greenhouse depends on factors such as the size, material quality, and any additional features you choose to include. On average, it can cost anywhere from $50 to $500.

Do I need any special skills or tools to build my own cold frame greenhouse?

Building your own cold frame greenhouse requires basic DIY skills and tools like screwdrivers and saws. However, there are simple designs that even beginners can tackle successfully with minimal experience.