High Tunnels: Extend Your Growing Season and Boost Your Harvest

As a fellow gardener, I understand the frustration of short growing seasons. You carefully nurture your seedlings, watch them sprout with anticipation, only to have them succumb to the first frost or a sudden hailstorm. It’s disheartening to see your hard work and investment disappear due to unpredictable weather.

This constant battle against Mother Nature can leave you feeling defeated and longing for a way to extend your harvest. You deserve to enjoy fresh, homegrown produce for more than just a few months out of the year.

That’s where high tunnels come in. These simple yet effective structures create a protected environment for your plants, allowing you to start planting earlier in the spring, continue harvesting well into the fall, and even grow certain crops throughout the winter. High tunnels are like giving your garden a cozy blanket, sheltering your plants from harsh weather and extending their productive period. They also help manage pests and diseases, reducing the need for chemical interventions. Whether you’re a seasoned gardener or just starting out, high tunnels can significantly enhance your gardening experience, offering a practical and affordable solution to maximize your harvest.e for a much longer period. You will find that the benefits of high tunnels are well worth the investment. Let’s dive in!

What Exactly are High Tunnels? (Defining the Structure)

Now that I’ve sparked your interest, let’s get down to the specifics. What exactly is a high tunnel? At its core, a high tunnel is a simple, cost-effective structure designed to protect crops and extend the growing season. It’s essentially a hoop-shaped or arched frame covered with a layer of polyethylene plastic. This creates a protected environment, a microclimate, that’s warmer and more stable than the outside world. You’ll often hear them called hoop houses or grow tunnels, and while there are slight variations, the basic principle remains the same.

Key Features of High Tunnels:

• Frame: The backbone of the structure. This is typically constructed from metal (galvanized steel or aluminum are common due to their durability and resistance to rust), though I’ve seen some smaller DIY versions made from wood or even PVC pipe. The frame provides the shape and support for the plastic covering.
• Covering: This is what creates the enclosed environment. It’s usually made from a single or double layer of polyethylene film, a type of plastic specifically designed for greenhouse and high tunnel use. This film is often treated to resist UV degradation from the sun, which is crucial for longevity.
• Ventilation: This is where high tunnels differ significantly from greenhouses. High tunnels rely primarily on natural ventilation. This is achieved through roll-up sides, end wall vents, and sometimes roof vents. Proper ventilation is essential for regulating temperature and humidity, preventing disease, and ensuring good air circulation.
• Anchoring: Because high tunnels are relatively lightweight, they need to be securely anchored to the ground to withstand wind and other weather conditions. Common anchoring methods include ground posts, stakes, and baseboards.

High Tunnels vs. Greenhouses: What’s the Difference?

It’s a common question: “Aren’t high tunnels just greenhouses?” While they share some similarities, there are key differences that set them apart. Here’s a quick comparison:

As you can see, high tunnels are a more economical and less energy-intensive option compared to greenhouses. They are a fantastic choice for gardeners who want to extend their growing season without the high costs associated with a fully heated and controlled greenhouse environment.

Types of High Tunnels: Finding the Right Fit for You

Just like there are different types of gardens, there are also different types of high tunnels. Here are a few common designs:

• Hoop Houses: These are the simplest and most common type. They have a rounded, hoop-like shape and are relatively easy to construct. I’ve even built a small one myself using PVC pipe and some readily available plastic sheeting.
• Gothic Arch High Tunnels: These have a pointed arch, resembling the shape of a gothic cathedral. This design is particularly useful in areas with heavy snowfall, as the pointed shape helps shed snow more effectively.
• Multi-Bay Tunnels: These are larger structures consisting of multiple connected hoops or arches. They’re ideal for commercial growers or gardeners with a lot of space and a desire for larger-scale production.

Choosing the right type depends on your needs, budget, and the specific conditions of your garden. If you’re just starting out, a simple hoop house is a great way to get your feet wet. As you gain experience and your needs evolve, you can always upgrade to a more complex design.

You now have a solid understanding of what high tunnels are and how they differ from other structures. In the next section, I’ll cover the many benefits these structures can bring to your garden.

The Perks of Using a High Tunnel (Why You’d Want One)

Now that you know what a high tunnel is, let’s talk about why you might want to add one to your garden. I’ve found that the benefits are numerous, and they go far beyond simply extending the growing season. You’ll find that a high tunnel can significantly improve your gardening experience in several ways.

Extending the Growing Season: More Time for Your Plants to Thrive

This is perhaps the most well-known benefit of high tunnels. By creating a protected microclimate, high tunnels allow you to start planting earlier in the spring and continue harvesting later into the fall. In some climates, you can even grow certain crops throughout the winter. I’ve personally been able to harvest tomatoes well into November thanks to my high tunnel.

Here’s how it works: the plastic covering traps solar heat, warming the air and soil inside the tunnel. This allows you to plant earlier in the spring, giving your plants a head start. Similarly, the protection from frost in the fall allows you to extend your harvest well beyond the first frost date. This extended season means more fresh produce for you, your family, and perhaps even your local community.

Protecting Crops from the Elements: A Shield Against Unpredictable Weather

Unpredictable weather can be a major challenge for gardeners. From late spring frosts to summer hailstorms, there are many weather events that can damage or even destroy your crops. High tunnels provide a valuable shield against these threats.

• Frost and Cold Snaps: High tunnels provide a buffer against sudden temperature drops, protecting your plants from frost damage.
• Heavy Rain and Hail: The plastic covering protects your plants from heavy rain and hail, which can damage delicate foliage and fruits.
• High Winds: High winds can damage plants, especially young seedlings. High tunnels provide a windbreak, protecting your plants from wind damage.
• Intense Sun: While sunlight is essential for plant growth, too much intense sun can cause heat stress and damage to some plants. High tunnels can help moderate the intensity of the sun, especially during the hottest part of the summer.

Improved Crop Quality and Yields: Bountiful Harvests and Healthier Plants

The protected environment inside a high tunnel not only extends the growing season but also improves crop quality and yields. Plants grown in high tunnels tend to be healthier and more productive due to several factors:

• Warmer Soil Temperatures: Warmer soil temperatures promote faster root growth and nutrient uptake, leading to healthier plants.
• Reduced Disease Pressure: The controlled environment inside a high tunnel can help reduce the incidence of certain plant diseases.
• Protection from Pests: While high tunnels don’t completely eliminate pests, they can help reduce pest pressure, especially from larger pests like birds and rabbits.

Pest and Disease Management: A More Natural Approach

While high tunnels don’t entirely eliminate pests and diseases, they can significantly reduce their impact. The physical barrier of the plastic covering helps keep out many larger pests, such as birds, rabbits, and deer. The improved airflow from proper ventilation also helps reduce the risk of fungal diseases.

I’ve found that I need to use far fewer pest control methods in my high tunnel compared to my open garden. This is a huge plus for those of you who prefer a more natural and organic approach to gardening.

Water Conservation: Making the Most of Every Drop

In many areas, water conservation is a growing concern. High tunnels can help you conserve water by reducing evaporation. The enclosed environment traps moisture, reducing the need for frequent watering. This is especially beneficial in dry climates or during periods of drought.

You now understand the many advantages that high tunnels offer. In the next section, I’ll guide you through the process of planning your high tunnel, ensuring you make the right choices for your specific needs and garden.

Planning Your High Tunnel (Before You Build or Buy)

Before you jump into building or buying a high tunnel, careful planning is essential. I’ve learned from experience that a little forethought can save you a lot of time, money, and frustration down the road. You’ll want to consider several key factors to ensure your high tunnel is a success.

Site Selection: Choosing the Perfect Spot

The location of your high tunnel is crucial. The right site can maximize sunlight, protect against wind, and ensure good drainage. Here are some key considerations:

• Sunlight: Just like any garden, high tunnels need plenty of sunlight. Aim for a location that receives at least 6 hours of direct sunlight per day, especially during the winter months. I recommend observing your garden throughout the day to identify the sunniest spot.
• Drainage: Avoid areas that tend to collect water. Poor drainage can lead to waterlogged soil, which can harm your plants and create a breeding ground for diseases. If your garden has poor drainage, you may need to amend the soil or create raised beds inside the high tunnel.
• Wind Protection: While high tunnels can withstand some wind, strong winds can damage the structure, especially the plastic covering. Consider placing your high tunnel in a location that is protected from prevailing winds, such as near a building, fence, or row of trees.
• Accessibility: Think about how you will access your high tunnel for maintenance, planting, and harvesting. Choose a location that is easily accessible with a wheelbarrow or other gardening tools.

Size and Dimensions: Finding the Right Fit

The size of your high tunnel will depend on your available space, your gardening goals, and your budget. Consider these factors:

• Available Space: Measure your garden space carefully to determine the maximum size of high tunnel you can accommodate.
• Gardening Goals: What do you plan to grow in your high tunnel? If you want to grow tall crops like tomatoes or cucumbers, you’ll need a taller structure. If you want to grow a large quantity of crops, you’ll need a larger footprint.
• Budget: Larger high tunnels will generally cost more to build or buy. Consider your budget and choose a size that you can afford.

Budget Considerations: Balancing Cost and Quality

The cost of a high tunnel can vary depending on whether you choose to build it yourself or buy a kit. DIY high tunnels can be more affordable, but they require more time and effort. Kits are more convenient but can be more expensive. Consider these factors:

• DIY Costs: Factor in the cost of materials such as framing, plastic covering, and anchoring systems.
• Kit Costs: Compare prices from different suppliers and consider the features included in each kit.
• Long-Term Costs: Consider the long-term costs of maintenance and replacement of materials, such as the plastic covering.

Local Regulations and Permits: Ensuring Compliance

Before you start building your high tunnel, it’s important to check local building codes and regulations. Some areas may require permits for structures of a certain size. Contact your local building department to ensure you are in compliance.

Comparing DIY vs. Kit High Tunnels

You’ve now learned the key considerations for planning your high tunnel. In the next section, I’ll provide a step-by-step guide to building your own high tunnel.

Building Your Own High Tunnel (DIY Approach)

For those of you who enjoy a hands-on approach, building your own high tunnel can be a rewarding and cost-effective option. I’ve built several high tunnels myself, and while it requires some effort, it’s definitely achievable with basic construction skills and the right tools. You’ll find that it’s a great way to customize your high tunnel to your specific needs and budget.

Materials List: Gathering Your Supplies

Here’s a basic list of materials you’ll need for a simple hoop house-style high tunnel:

• Hoops: These can be made from metal conduit, PVC pipe, or even wood. Metal conduit is the most durable option, but PVC is a good choice for smaller, more affordable structures.
• Plastic Covering: Choose a greenhouse-grade polyethylene film that is UV-resistant. This will protect your plants from the sun’s harmful rays and ensure the covering lasts for several seasons.
• Baseboards (Optional): These are wooden boards that run along the base of the high tunnel, providing a sturdy foundation for attaching the plastic covering.
• Anchoring System: This can include ground posts, stakes, or anchors. The type of anchoring system you choose will depend on the size of your high tunnel and the wind conditions in your area.
• Fasteners: You’ll need screws, bolts, or clips to attach the plastic covering to the frame.
• Door and Ventilation Materials: This can include lumber, hinges, and hardware for building a door, as well as materials for creating roll-up sides or vents.

Step-by-Step Construction Guide: Putting It All Together

Here’s a simplified step-by-step guide to building a hoop house-style high tunnel:

1. Prepare the Site: Clear the area where you will be building your high tunnel and level the ground.
2. Install the Hoops: Space the hoops evenly apart and drive them into the ground.
3. Attach the Baseboards (Optional): If using baseboards, attach them to the base of the hoops.
4. Install the Plastic Covering: Drape the plastic covering over the frame and secure it to the baseboards or hoops using fasteners.
5. Install the Door and Ventilation System: Build a door and install it at one end of the high tunnel. Create roll-up sides or vents for ventilation.
6. Anchor the High Tunnel: Secure the high tunnel to the ground using your chosen anchoring system.

Tips for Success: Making Your High Tunnel Sturdy and Effective

Here are a few tips to help you build a successful high tunnel:

• Use sturdy materials: Invest in high-quality materials that will withstand the elements.
• Ensure proper ventilation: Adequate ventilation is crucial for regulating temperature and humidity inside the high tunnel.
• Anchor the high tunnel securely: This will prevent it from being damaged by wind.
• Consider adding a second layer of plastic: This can provide additional insulation and help retain heat during the winter months.

PVC vs. Metal Framing: Weighing the Pros and Cons

Here’s a quick comparison of PVC and metal framing:

You now have the information you need to build your own high tunnel. In the next section, I’ll discuss the option of buying a high tunnel kit.

Buying a High Tunnel Kit (Ready-Made Options)

If the idea of building your own high tunnel feels a bit daunting, or if you’re simply short on time, buying a high tunnel kit is an excellent alternative. I’ve found that kits offer a convenient and often more streamlined approach to setting up your protected growing space. You’ll have everything you need in one package, with clear instructions to guide you through the assembly process.

Types of Kits Available: Finding the Right Style and Size

High tunnel kits come in a variety of styles and sizes to suit different needs and budgets. Here are a few common types:

• Hoop House Kits: These are the most common and affordable type of kit. They typically include pre-bent metal hoops, plastic covering, and anchoring hardware.
• Gothic Arch Kits: These kits offer a stronger structure that is better suited for areas with heavy snowfall.
• Multi-Bay Kits: These are larger kits that include multiple connected hoops or arches, providing a larger growing area.

Factors to Consider When Buying: Making an Informed Decision

When choosing a high tunnel kit, there are several important factors to consider:

• Frame Material: Look for kits with galvanized steel or aluminum frames, as these are the most durable and resistant to rust.
• Covering Material: Choose a kit with a greenhouse-grade polyethylene film that is UV-resistant and at least 6 mil thick.
• Ventilation Options: Ensure the kit includes adequate ventilation options, such as roll-up sides or end wall vents.
• Warranty: Check the warranty offered by the manufacturer. A good warranty can give you peace of mind knowing that your investment is protected.
• Customer Reviews: Read online reviews from other customers to get an idea of the quality and ease of assembly of the kit.

Where to Buy Kits: Finding Reputable Suppliers

High tunnel kits are available from a variety of sources, including:

• Online Retailers: Many online retailers offer a wide selection of high tunnel kits at competitive prices.
• Local Farm Supply Stores: Check with your local farm supply stores, as they often carry high tunnel kits or can order them for you.
• High Tunnel Manufacturers: Some manufacturers sell their kits directly to consumers.

You now have a good understanding of the different types of high tunnel kits available and the factors to consider when buying one. In the next section, I’ll share some essential tips for growing successfully in your high tunnel.

Growing in a High Tunnel (Optimizing Your Harvest)

Now that your high tunnel is set up, the real fun begins: growing! I’ve discovered that growing in a high tunnel is a unique and rewarding experience. You’ll have more control over your growing environment, which can lead to healthier plants and bigger harvests. You’ll find that there are some key differences compared to growing in an open garden.

Crop Selection: Choosing the Right Plants for Your Protected Space

While you can grow many different crops in a high tunnel, some thrive particularly well in this environment. Here are a few recommendations:

• Tomatoes: These are a popular choice for high tunnel growing, as they benefit from the warm, protected environment.
• Peppers: Like tomatoes, peppers thrive in the warm conditions of a high tunnel.
• Cucumbers: These vining plants appreciate the support and warmth provided by a high tunnel.
• Leafy Greens: These can be grown year-round in many high tunnels, providing a continuous supply of fresh greens.
• Berries: Strawberries, raspberries, and other berries can benefit from the protection of a high tunnel, resulting in earlier and larger harvests.

Soil Preparation and Management: Building a Healthy Foundation

Healthy soil is essential for successful high tunnel gardening. Here are some tips for preparing and managing your soil:

• Soil Testing: Before planting, it’s a good idea to get your soil tested to determine its pH and nutrient levels.
• Soil Amendments: Amend your soil with compost or other organic matter to improve its fertility and drainage.
• Crop Rotation: Practice crop rotation to prevent the buildup of soilborne diseases.

Watering and Irrigation: Providing Consistent Moisture

Proper watering is crucial in a high tunnel environment. Here are some tips:

• Drip Irrigation: This is often the most efficient method for watering in a high tunnel, as it delivers water directly to the roots of the plants.
• Watering Frequency: Water your plants regularly, especially during hot weather. Check the soil moisture regularly to determine when to water.

Ventilation and Temperature Control: Maintaining a Balanced Environment

Proper ventilation is essential for regulating temperature and humidity inside your high tunnel. Here are some tips:

• Roll-Up Sides: Open the roll-up sides on warm days to allow for airflow.
• End Wall Vents: Open the end wall vents to further improve ventilation.

Pest and Disease Control: Keeping Your Plants Healthy

While high tunnels can help reduce pest and disease pressure, it’s still important to monitor your plants regularly. Here are some tips:

• Integrated Pest Management: Use a combination of methods to control pests, including handpicking, traps, and organic sprays.
• Disease Prevention: Practice good sanitation and ventilation to prevent the spread of diseases.

You’re now equipped with the knowledge to grow successfully in your high tunnel. In the next section, I’ll discuss how to maintain your high tunnel to keep it in top shape for years to come.

Maintaining Your High Tunnel (Keeping it in Top Shape)

To ensure your high tunnel provides years of reliable service, regular maintenance is key. I’ve learned over time that a little preventative care can go a long way in extending the lifespan of your structure and maximizing its productivity. You’ll find that these tasks are generally straightforward and well worth the effort.

Cover Maintenance: Protecting Your Investment

The plastic covering is the most vulnerable part of your high tunnel, so it requires regular attention. Here are some tips for maintaining your cover:

• Cleaning: Regularly clean the plastic covering to remove dirt, dust, and debris. This will help maximize light transmission and prevent the buildup of algae or mold. I usually use a soft brush and mild soap and water.
• Inspecting for Damage: Regularly inspect the covering for tears, punctures, or other damage. Repair any small tears with greenhouse tape. For larger tears, you may need to replace a section of the covering.
• Tightening the Covering: Over time, the plastic covering can become loose. Regularly tighten the covering to prevent it from flapping in the wind, which can cause further damage.

Frame Maintenance: Ensuring Structural Integrity

The frame of your high tunnel also requires some maintenance to ensure its structural integrity. Here are some tips:

• Inspecting for Rust or Damage: Regularly inspect the frame for rust, corrosion, or other damage. Repair or replace any damaged parts.
• Tightening Connections: Check all bolts, screws, and other connections to ensure they are tight. This will help prevent the frame from becoming loose or unstable.

Winterizing Your High Tunnel: Preparing for the Cold Months

If you live in an area with harsh winters, it’s important to winterize your high tunnel to protect it from snow and wind damage. Here are some tips:

• Removing Snow: Regularly remove snow from the roof of the high tunnel to prevent it from collapsing under the weight of the snow.
• Securing the Covering: Ensure the plastic covering is tightly secured to prevent it from being damaged by wind.
• Opening Vents: Open the vents to allow for air circulation and prevent the buildup of humidity, which can lead to fungal diseases.

High Tunnel Maintenance Schedule

By following these maintenance tips, you can keep your high tunnel in top shape for years to come, ensuring many seasons of successful gardening. In the next section, I’ll address some frequently asked questions about high tunnels.

Common High Tunnel Questions (FAQ)

I often get questions about high tunnels from fellow gardeners, so I thought it would be helpful to address some of the most common ones here. You may have some of these questions yourself, and I want to provide you with clear and concise answers.

By addressing these common questions, I hope I’ve provided you with a better understanding of high tunnels and their potential benefits for your garden. In the next section, I’ll offer some final thoughts and encouragement.

Conclusion (Enjoying the Fruits of Your Labor)

I’ve covered a lot of ground in this guide, from the basics of what high tunnels are to the specifics of building, buying, growing, and maintaining them. My goal has been to provide you with the information and inspiration you need to take your gardening to the next level. I sincerely hope that you find high tunnels as beneficial as I have.

While extending the growing season is a major benefit, I’ve discovered that high tunnels offer so much more. They provide a sanctuary for your plants, protecting them from the unpredictable whims of nature. They create a space where you can experiment with new crops, push the boundaries of your local climate, and enjoy the satisfaction of harvesting fresh, homegrown produce for a larger part of the year.

I understand that investing in a high tunnel, whether you build it yourself or buy a kit, requires time, effort, and resources. But I truly believe it’s a worthwhile investment. Not only will you see a return in the form of increased yields and improved crop quality, but you’ll also gain a deeper connection to your garden and the natural world.

If you’re considering adding a high tunnel to your garden, I encourage you to give it a try. Start small if you need to, perhaps with a simple hoop house. You can always expand or upgrade later as you gain experience. You might be surprised at how much of a difference it can make.

I wish you all the best in your high tunnel gardening adventures. May your harvests be bountiful and your gardening experience be even more rewarding!

Remember, every gardening journey starts with a single seed. With a little planning, effort, and the help of a high tunnel, you can cultivate a thriving garden that provides you with fresh, healthy produce for many seasons to come.

I hope this comprehensive guide has been helpful and informative. Happy gardening!