Whether you’re operating a roadside farmer’s market or you’re a major commercial grower, investing in a high tunnel greenhouse can have a significant impact on your bottom line.
These structures will expand your growing season, protect your crops, and improve your harvest – all at a fraction of the cost of a traditional commercial greenhouse. Commercial farmers across the United States are enjoying the benefits of high tunnel greenhouse growing. If you’re ready to join them, there are a few things you need to know.
The following guide will take a deep dive into how a high tunnel greenhouse works, some of the top benefits, and the most important growing tips.
What is a High Tunnel Greenhouse?
A high tunnel greenhouse, also known as a cold frame greenhouse or a hoop building, is a large, unheated structure made from a steel frame and a translucent fabric cover. It doesn’t require a heater, fan, or other equipment designed to control the internal environment. Instead, they rely on insulation and solar heat to create warmth inside.
When deciding on the right high tunnel greenhouse for your needs, you’ll want to pay attention to the quality of materials. It's also important to consider the dimensions of the structure versus the space you have available and the volume of crops you plan to grow.
While high tunnel greenhouses come in a variety of sizes, ShelterTech High Tunnel Greenhouses are built to order and are fully customizable. They’re made from extra-tough galvanized steel frames that provide maximum protection from rust and corrosion. The brand's exclusive LUMINATE covers are also designed to diffuse light more evenly than other cold frame commercial greenhouses.
7 Benefits of Using a High Tunnel Commercial Greenhouse
Both amateur and professional growers will enjoy the many benefits of using a greenhouse. Here’s a look at just a few of the advantages these affordable structures will provide.
1. Protection from Severe Weather
A high tunnel greenhouse will protect your crops from the negative impact of heavy rain, high winds, snow, hail, and drought. Since the covers diffuse light, they also provide shade, protecting crops from excess heat and sunburn.
A high tunnel greenhouse can also improve your efficiency by allowing you to work under cover and harvest your crops in all types of weather.
2. Extended Growing Season
A high tunnel greenhouse extends your growing season. On a warm, sunny day, the temperature inside your greenhouse will generally be 30 to 50 degrees warmer than the outdoors. This allows for rapid growth.
In addition, you can also harvest cold-hardy crops much later into the fall and winter seasons. No matter which region of the United States you’re located in, you can expect to get at least a few extra months of growing when using a high tunnel greenhouse.
3. Irrigation Control
Growing crops under the cover of a high tunnel greenhouse gives you the power to control the amount of irrigation they receive. This creates additional protection from the perils of flooding or drought and allows you to use precise tools like drip irrigation systems. These systems provide precision watering and the ability to deliver additional nutrients to your plants.
4. Protection from Pests
A high tunnel greenhouse will help keep insects, diseases, and plant-eating animals away from your crops. This will keep your plants healthier and reduce or possibly even eliminate the need for insecticides. Growing crops inside a greenhouse will also reduce the number of weeds you’ll have to battle.
5. Better Soil Health
While growers using traditional greenhouses typically plant their crops above ground, a high tunnel greenhouse allows you to choose whether to plant crops in raised beds or directly in the ground. This also allows growers to use a variety of soil health practices, such as crop rotation and using cover crops. This helps increase the soil’s water content, suppresses weeds, and can help break pest cycles.
6. Increased Yields and Income
All of the factors listed above help increase crop yields. Not only will you likely get more crops over a longer period of time, but you may also be able to grow larger, higher-quality crops as well.
For commercial growers, increased yields mean higher income. If you’re able to grow produce when it’s technically “out of season,” you may also be able to charge a premium for those items. This can add even more to your bottom line.
When compared to a traditional greenhouse, a high tunnel greenhouse is far more affordable. Not only is the structure itself less expensive, but you won’t have to purchase and maintain a heater and ventilation system.
In addition, the USDA Natural Resources Conservation Service may be able to offer financial assistance for your high tunnel greenhouse purchase through the Environmental Quality Incentives Program (EQIP).
What to Grow in Your Commercial Greenhouse
If you’re wondering what you can grow in your new high tunnel greenhouse, the answer is – just about anything! While you’ll still want to follow a crop’s typical growing season, your high tunnel will allow you to start planting earlier in the spring and keep harvesting into the winter months. In some areas, you may even be able to grow crops year-round.
While you “can” grow almost any crop in a high tunnel greenhouse, if you’re wondering what you “should” grow, that answer might be different. As a commercial grower, you’ll want to grow crops that allow you to maximize your income. To do this, the crops you choose should:
- Be of high value year-round
- Require less maintenance in a high tunnel than they do in a field
- Have a high yield and a low chance of diseases and pest attacks
Best High Tunnel Winter Crops
If you can grow the right crops in your high tunnel during the winter months, you’ll enjoy a nice return on your investment. Some of the highest-ROI crops to grow in the winter include:
- Raspberries and blackberries
- Cut flowers
- Green onions
Other winter crops grow well in a high tunnel and will make you some profit, although not as much as those listed above. This includes:
- Snap peas
- Swiss chard
Tips for Selecting High Tunnel Crops
During the spring, summer, and fall months, the best crops to plant in a high tunnel are those that are either fully ready to harvest within 60 days (for example, spinach and lettuce) or those that continue producing crops for several months (such as peppers and tomatoes).
You’ll want to avoid using this valuable space for crops that grow slowly and only produce once. For example, sweet corn and broccoli are not good for commercial growers using a high tunnel greenhouse.
One exception to this is vining crops like squash, cucumbers, or even melons. If you can trellis and prune them so they produce early and/or late in the season, this can be a productive use of your greenhouse space.
Many commercial growers also use their high tunnels to grow seedlings, then transplant them to the field when the plants are strong enough and the weather permits. When using this method, the goal is to time your rotations so that as soon as one group of crops moves out, the next one is ready to go in.
Ultimately, you’ll want to choose the crops and planting methods that will help you produce the greatest amount of income per square foot. In almost all cases, this means selecting the crops that will “earn their keep” the fastest.
Tips for Better Crop Yields
When planting crops in your high tunnel greenhouse, using commercial greenhouse growing best practices can help you maximize your income. Here are a few tips to consider.
1. Limit Walkway Space
While planting crops in neat rows makes sense out in the field where you’re using a tractor for your cultivation, in a high tunnel greenhouse, it’s really a waste of space. Generally, you’ll have better luck planting large beds that are anywhere from 30 inches to four feet. This will allow you to make the best use of your soil and avoid taking up high-value space with unnecessary walkways.
While you’ll want to easily access plants like lettuce that can be harvested throughout the season, consider limiting pathways around other types of crops.
2. Plant Early
Many people think of greenhouses as a great way to extend the growing season. However, you can also use them to get a head start. For example, you may want to plant crops like cucumbers and tomatoes early so you can harvest and sell them before everyone else. Then, in the peak summer months, when these crops are abundant and prices are low, you can use your high tunnel to start getting your fall crops ready, so you can also harvest them ahead of the traditional season.
3. Keep Your High Tunnel Full Year-Round
Even if you’re not used to growing all year long, you’ll get a better return on your investment if you plan to keep your high tunnel full of plants all year long. Even if you don’t have a market for winter crops, you may want to plant some foods that you will enjoy eating. You can also consider taking excess crops to farmer’s markets or setting up your own roadside stand.
Using High Tunnels to Increase Your Bottom Line
If you follow these simple tips, it’s almost impossible not to see an increase in your bottom line after investing in a high tunnel greenhouse. With just a bit of forethought, you’ll be able to turn these structures into one of the most valuable and productive spaces on your land.