How to Build a Greenhouse
If you are looking into how to build a greenhouse, you probably already know that a backyard greenhouse can expand your growing season and allow you to grow a cutting garden or food for your family throughout the year. Greenhouses allow you to harness the energy of the sun to heat the space and to better control the growing environment for a more abundant yield. They also allow you to grow plants that you may not otherwise be able to grow in your area and can save time and money on things like pesticides, herbicides, and pulling weeds.
10 Benefits of Having a Greenhouse
There are many benefits of growing plants in a greenhouse, some of which depend on where you live. For example, folks living in colder climates can benefit from an extended growing season, while folks who live on the coast might benefit more from the protection greenhouses offer from wind and salty air.
Here are just 10 benefits you can enjoy when growing plants in a greenhouse.
1. Longer growing season:
One of the main reasons people explore how to build a greenhouse is to benefit from the extended growing season they offer in colder climates.
2. Protection from bad weather:
A greenhouse protects your plants from heavy rain, harsh winds, and freezing temperatures. Your greenhouse also protects you from all of these while you are gardening.
3. More control over growing environment:
Greenhouses allow you to control more aspects of the growing environment, such as soil choice, controlling the temperature, and protecting your plants from inclement weather. This allows you to create a better growing environment to help your plants thrive.
4. Expanded plant variety:
When you have more control over the growing environment, you have the opportunity to grow a wider variety of plants that may not thrive in your area without the help of a greenhouse.
5. Fewer weeds:
In a closed environment, there is less wind to blow weed seeds and no birds or other critters to drop the seeds or poop out the seeds in your garden. This helps reduce the amount of weeds you have to contend with when gardening in a greenhouse.
6. Fewer pests:
Greenhouses help protect your plants from deer, birds, squirrels, rabbits, and other critters who want to get into your garden and eat your food.
7. Fewer pesticides:
Growing in greenhouses means fewer harmful pests overall, which means you can use fewer (or no) pesticides when growing food plants or ornamentals.
8. Save money by growing your own food:
A properly controlled greenhouse allows for larger yields than you will see in an outdoor garden. This means that you can maximize production and save money on produce by growing some of your own food. Since there is an upfront cost for building a greenhouse, how soon you start saving money will depend on how much you spent on your greenhouse and the supplies to start your garden.
9. Better environment for seed starting:
Rather than stacking seed trays in any open spot in your house or garage, you can easily start seeds and care for your seedlings in your greenhouse. This allows for a great environment for starting seeds and caring for your young plants until you are ready to transplant them into your garden.
With a well-made greenhouse you can harness solar energy to use for heat and install a drip system to save water.
Disadvantages of Greenhouses
Most gardeners consider the benefits of having a greenhouse to far outweigh the disadvantages, but there are a few to note before building your own greenhouse in your yard.
The most obvious disadvantage of greenhouses is the upfront cost. While there are some small, DIY options that are less than $100, a good greenhouse can easily cost hundreds or thousands of dollars to purchase and install. You then have the costs of pots, potting soil, a drip system, and other supplies and materials.
Once your greenhouse is up and running, there may be ongoing operation costs. This is mostly true if you heat or cool your greenhouse to extend your growing season. Heat is generally the biggest ongoing cost for greenhouse owners, however, even for folks who are solely using the sun’s energy to heat their greenhouse, there will be some maintenance costs over the years.
Another significant disadvantage to growing in a greenhouse is that you do not enjoy the benefit of pollinators helping to ensure a bountiful harvest of flowers or fruits. An enclosed greenhouse allows you to control the growing environment, but it also means that you must take on the task of pollinating your plants by hand.
For gardeners living in warmer climates – like most of Southern California – it is important to pay attention to venting and placement. A greenhouse that receives direct sun and is not properly vented can easily kill your plants on a hot day.
Best Plants for Greenhouses
The best plants to grow in greenhouses depends on the climate where you live. Most people grow in either containers or raised garden beds when growing in a greenhouse. Therefore, one of the first things to look for is plants that do well in your growing situation. If you are growing everything in containers, you will need to choose plants that thrive in container gardens.
The next step is to consider the climate you can create and control in your greenhouse. If you have heating, cooling, and humidity control systems in place to create and maintain a specific microclimate, then you will have the best success with plants that thrive in that microclimate. For example, you may create a climate that is ideal for a tropical garden filled with orchids or a desert garden filled with cacti and succulents.
In general, most gardeners find success growing a wide variety of vegetables and ornamentals in backyard greenhouses. Poinsettias and chrysanthemums are particularly popular on the ornamental side. For food plants, tomatoes, herbs, peppers, squash, and cucumbers are popular for warm-season greenhouse growing, and lettuce, carrots, peas, and broccoli are good for cool-season growing.
How to Build a Greenhouse: Choosing Style and Materials
Greenhouses come in all shapes and sizes and can be simple structures or elaborate buildings. You can purchase a small, easy-to-assemble greenhouse kit for less than $50, or you can pay thousands of dollars to a contractor for a gorgeous, metal and glass greenhouse that will last a lifetime. There are options for every budget and every skill level, so let’s look at how to build a greenhouse that best suits your needs.
The first step in building a greenhouse is determining the type of greenhouse that you want. The initial decision is based on whether or not you intend to include a climate-control system. While climate-control systems are generally the costliest ongoing expense, they may be critical to the success of your greenhouse if you live in a colder climate or want to grow tropical plants.
A cold house does not have climate-control equipment and solely uses the energy from the sun to keep the greenhouse warm. In areas with freezing temperatures, this type of greenhouse will allow the temperature inside to freeze as well.
A cool house is designed to allow you to maintain the temperature around 45 to 50 degrees to avoid freezing temperatures.
A warm house allows you to use the climate-control system to keep the temperature around 50 degrees, which allows gardeners in colder climates to continue growing a variety of plants through winter.
A hot house is the most expensive to heat, since it keeps the temperature consistently above 60 degrees and requires heaters to do so. This type of greenhouse is most often used to grow tropical plants.
If you are considering including a climate-control system to keep your greenhouse warm, you will need to consider your options, which include radiant heat, soil-heating pipes, forced air, space heaters, or passive solar heat. If you choose to use electric or gas heating sources to heat your greenhouse, consider also adding a passive solar heating option to cut costs and conserve energy.
Once you have determined the type of greenhouse you want and the heating equipment you might include, the next step is finding a size and design that works in your yard. The best way to do this is to spend some time online looking at greenhouse designs to see what resonates with you. There are significant differences in cost depending on the design and materials, so this may also factor into your design decisions.
The most common greenhouse styles from which to choose are lean-to greenhouses, A-frame greenhouses, dome greenhouses, Quonset greenhouses, and arched greenhouses.
The most popular framing materials are wood, aluminum, iron, and plastic. Wood is an attractive option, but it requires the most maintenance, so be sure to consider that when choosing materials. Plastic, such as PVC pipes, is often the most affordable and easiest to work with for folks who are not accustomed to building structures.
You will also need to choose covering materials for your greenhouse. There are several options that vary greatly in price and longevity, including glass, acrylic, fiberglass, polyethylene, PVC, and plastic. Glass and acrylic are the most expensive options on this list, but they are also the most attractive and generally last longest. For folks on a budget, plastic might not be as attractive as glass, but it is an inexpensive, effective option that is easy to DIY.
Before you can order a kit, design your DIY build, or hire a contractor, you will also need to measure the space to determine how large your greenhouse can be and to determine a location that receives adequate sunlight and has good drainage.
How to Build a Greenhouse: Kits, Contractors, and DIY Builds
Once you have an idea of the style of greenhouse that will work best for you and the materials and equipment you need, it is time to determine how to build a greenhouse for your backyard. Here are the basic options.
1. Hire a contractor.
The option that is most likely to end with a satisfactory result is hiring a professional experienced in building greenhouses. This, of course, is also the option that will be the most expensive. You can work with him or her on the design, or look for greenhouse designs online that you can give your contractor for inspiration.
2. Purchase a kit.
If you are not going to hire a contractor and are not particularly handy, a greenhouse kit is the way to go. Styles and prices vary quite a bit when it comes to kits, so there is sure to be an option available that will suit your needs and your budget.
For example, the simple greenhouse as seen here is approximately 56x56x76 and is an easy-to-assemble kit with an alloy steel frame and polyvinyl chloride covering. At the time of this writing, this DIY greenhouse kit costs less than $70 online and will take most folks just a couple of hours to assemble.
If you are a bit handier, the polycarbonate greenhouses are a more attractive option but is still portable and easy to assemble. The 6′ x 10′ x 7′ is less than $1000.
If you are looking for a metal and glass greenhouse kit that is much more attractive and will last longer than the above options, there is also this 150-square-foot greenhouse that comes with a misting system and foundation frame for $6,900.
These are just a few examples of the wide variety of greenhouse kits that can be easily purchased online or at your local garden center or home improvement store. If you plan on building your own greenhouse, a kit is the easiest, quickest option. The kit comes with all of the materials you need and instructions that spell out how to assemble it step by step. This means no measuring, cutting, or running back and forth to the hardware store for more supplies.
3. Build it from scratch.
Building your own greenhouse from scratch is always an option and might be the right choice for handy homeowners interested in customizing the structure to fit their needs and garden space. You can look for greenhouse designs online, or you can create your own custom drawings from which to work. Finding a design online will provide you with step-by-step instructions for how to build a greenhouse and will provide a materials list that will greatly assist you when shopping for building supplies. So, while you can draw up your own greenhouse plans, following a proven design that comes with instructions and a materials list will certainly make this a simpler, quicker, more satisfying project.