If you’re planning on going off the grid or are working on creating a cache of survival supplies, being able to grow your own food is a necessity. In warm climates, that is easy — places like Texas and Florida have incredibly long growing seasons, so you can stagger your planting and harvest all year. Some staples, like potatoes, even grow best over the winter.
If you don’t live in one of the states that has an 11-month growing season, harvesting enough food to feed your family might seem challenging. You have two options. The first is to plant massive fields and preserve or can your harvest, hoping that it’s enough to last you through the winter until spring plants start to fruit. This isn’t a bad idea, especially if you like the taste of canned green beans, but it isn’t the only option.
The second, even better option, is to build your own greenhouse. Don’t let the idea of a DIY greenhouse intimidate you. Here’s why you should consider building your own and what you’ll need to get the job done.
Why You Need a Greenhouse
Greenhouses allow you to create whatever kind of climate you need to cultivate your crops, regardless of what the weather looks like outside. There might be snow on the ground, but the inside of your greenhouse will be warm and humid. Therefore, you can start germinating crops weeks or months earlier than you might be able to do outside.
It can also be a valuable tool if you live in a very dry area. Instead of wasting all your precious water to grow outdoor crops, a greenhouse lets you capture and retain the humidity necessary for cultivating nearly anything with maximum efficiency.
For instance, you can cultivate strawberries year-round, if that’s what tickles your fancy. Or plant a crop of exotic peppers that are not native to your climate zone. Let your imagination go.
Designing Your Greenhouse
Step one is the design phase. You need to determine what kind of greenhouse you want on your property and how big the final structure needs to be to meet your needs. There are eight different types of greenhouses you might see out in the world, including:
- A-frame: This is a very simple triangular greenhouse you can build for very little, though they do present airflow challenges in the lower corners.
- Sawtooth: It has a staggered roof with large verticle gaps that are ideal for ventilation.
- Lean-to: These have simple designs and are attached to the side of your existing home. They must be south-facing to ensure they get enough sunlight.
- Hoop house: Easy to build on a budget, these greenhouses are made with plastic sheeting stretched over metal hoops.
- Gothic arch: Similar to the hoop house, they have a sharp peak that sheds rain and snow better than round hoops do.
- Gabled roof: This is the traditional greenhouse design that you’re probably familiar with. It’s common but not the only option.
- Geodesic dome: If you want to get really fancy, greenhouse domes are an option. These provide a fantastic amount of growing space and ventilation but can be pricey to build.
- Shade house: Not every plant species needs direct sunlight. Shade houses are only necessary for specific kinds.
These are just here to give you an idea of where to start — you don’t have to stick to any one of these designs. Create a greenhouse that will work best for your needs and space.
Figuring Out Where to Put It
Before you break ground, you need to figure out where the final structure will sit once you complete it. You need a flat area with good drainage to keep your food crops from flooding during heavy rains. Ideally, a space that gets a lot of south- or southeast-facing sunlight will be the best option, especially in the winter.
This is a general suggestion. Examine your property throughout the year and see what spots get the best sunlight during the less-than-optimal growing seasons. Try to situate your greenhouse lengthwise, stretching from north to south. That way, it gets the most light possible while the sun travels from east to west across the sky.
Don’t Forget Building Permits
This step will vary depending on where you live. In some areas, you’ll need to obtain building permits before you can add a greenhouse to your property. Don’t start construction without checking with your local code enforcement office. Failing to obtain the necessary licenses can leave you with some expensive fines. In some situations, you may even have to tear down your newly built greenhouse — at your expense — and get new permits before you can rebuild.
Even if you’re going off the grid, it’s a good idea to stay on the good side of your local city council. It will save you a lot of money and trouble in the long run.
Now that you’ve got a design in mind and have all the necessary paperwork to legally break ground, you need to choose your materials. There are two categories — frame and exterior.
Aluminum frames are lightweight and easy to assemble but will be more expensive. Wood frames, on the other hand, provide a heavy-duty structure, but they need to be treated before you finalize your assembly to protect them from water damage and pests. The last thing you want is for your frame to start rotting and collapse in the middle of a growing season.
The exterior materials you choose will depend largely on the style of greenhouse you’re building. The hoop house and gothic arch style utilize plastic sheeting. You might find this in precut sections that match your design, but if you’re constructing this from scratch, you’ll most likely be working from rolls of sheeting.
[Editor’s note: My father-in-law has used a hoop house with a heavy-duty plastic sheeting made specifically for greenhouses for several years now, and it’s held up well in the Midwest climate.]
For other styles, you have a few more options. Glass is traditional, but it can be heavy, expensive, and hard to repair or replace if a stray hailstone or errant bird decides to smash its way into your greenhouse. Plastic sheeting is more common in modern greenhouses. It’s lightweight, insulates beautifully, and is easy to cut to size if you need to repair or replace a section.
Depending on your needs, you may want to opt for frosted acrylic or other plastic sheets. These materials will prevent the exterior from concentrating the sunlight and damaging your crops.
Buy a Kit or Build From Scratch?
Finally, before you start assembling, you have one last question to ask yourself. Should you collect the materials and build your greenhouse from scratch, or buy a kit?
This is entirely up to you. If you’re planning on using a traditional design or have found a kit that offers everything you’re looking for, then go with that. There is nothing inherently wrong with them. You’ll only run into problems if you’re trying to build something that strays from the kit’s intended design.
If you’ve got a custom greenhouse in mind or can find a better deal on materials, building from scratch might be your best option.
Build Your Greenhouse
You’ve finally reached the moment you’ve been waiting for since you started this project: It’s time to break ground and actually start building your greenhouse. Start by leveling the land in your chosen space. It might look nice and even, but it’s always a good idea to ensure everything is flat before you start. The last thing you want to do is start building, only to find a barely perceptible hump or dip in the soil.
Next, you’ll want to construct your frame. Don’t worry about adding your exterior yet. Simply get it in place and ensure it’s structurally sound. Once you have it put together, you can worry about enclosing the building with your chosen exterior.
That’s all there is to it. Congratulations, you’ve got a greenhouse! Don’t get comfy though, you’re not done yet.
The ventilation system in a greenhouse has four jobs: It helps prevent pest infestations, encourages pollination, regulates temperature and helps all your plants get plenty of fresh air. Without adequate ventilation, even the best greenhouse is going to fail, and your crops will die. In a survival or off-grid scenario, this could leave you hungry for a season.
You can use several different tools for greenhouse ventilation. If you live in an area that gets plenty of wind, just opening a window or two can encourage airflow. This isn’t always an option, especially during the colder months, so you’ll need other ways to keep the air moving.
Fans are a popular choice. Air compressors can also keep things moving within an otherwise closed system. If you opt for an air compressor, make sure you’re maintaining it to optimize efficiency. Modern compressors already run at about 10% efficiency, losing the rest of their power to heat. Make sure you’re not falling below that mark. Consider investing in a heat recovery system to reclaim some of that energy in the form of warmth you can use to keep your greenhouse warm during cooler months.
[Editor’s note: Unfortunately, a fan is probably going to be necessary in the harsh summer months because a greenhouse can get very warm inside! If you’re off-grid then you really need to design in plenty of cross-ventilation.]
Water and Electricity
Water is just as important as ventilation when it comes to keeping your plants alive. In an off-the-grid scenario, tapping into the local water supply isn’t an option. However, that doesn’t necessarily mean you’re relegated to watering everything by hand. Consider investing in a gravity-fed irrigation system that you can fill with rainwater or manually, depending on your needs and the amount of rainfall you get.
Electricity might be a little bit trickier, especially if you’re off-grid or the power goes out. It isn’t always strictly necessary — you can heat and cool your greenhouse without it. That said, if you find yourself in need of grow lights or other electrical equipment, you’ll need to wire your greenhouse to your off-grid power supply.
This will be the most important thing you install in your new greenhouse before you start planting. Different species require various temperatures to thrive, and if your greenhouse gets too hot or too cold, your plants won’t survive. Even if they do, they likely won’t fruit. If you build your greenhouse correctly, retaining heat shouldn’t be a problem. You don’t want things to get too warm, though, and that’s where a thermometer comes in.
Install your thermometers or sensors away from your windows or other ventilation areas to get an accurate picture of the temperature within your greenhouse. If you put them near your doors or windows, you’ll read the ambient outdoor temperature instead.
Plant and Monitor Temperatures
Now, you’re ready to plant your crops. You have a couple of options here. You can choose to plant directly in the ground, which can be beneficial if you have fertile soil under your greenhouse, or setup grow-beds. Whichever you choose, get your crops planted and make sure you’re monitoring temperatures. If you’re placing them in the ground, you may want to invest in a temperature probe for your soil to ensure the roots aren’t getting too cold.
[Editor’s note: Grow beds, especially of differing heights, makes your greenhouse more efficient and easier to care for day to day. Plus, you can take advantage of smaller temperature differences.]
Now that you’ve got your crops in the ground or your planters, you’ve got a fully functional greenhouse. It’s just like taking care of any other garden — watering, weeding, dealing with pests, and when the time comes, harvesting the fruits of your labor.
The best thing about having your own greenhouse is that you can grow and harvest fresh fruits and vegetables year-round. It takes a little bit of practice to learn how to navigate things like temperature and humidity in an enclosed space. Once you have that skill mastered, you’ll never have to worry about planting too early or too late ever again. Losing crops to an early frost will be a thing of the past.
With a bit of planning and preparation, adding a greenhouse to your property is easily one the best things you can do for survival and off-the-grid living.
Emily Folk is a conservation and sustainability writer and the editor of Conservation Folks.
[Note: This was a guest post.]