How to Build a Simple Greenhouse
A greenhouse in the garden is a great way to get a head start of the growing season. This is particularly helpful if you live in such a climate area where getting some additional weeks and months is very helpful for growing more plants.
Unfortunately, commercial greenhouses tend to be expensive, so not everybody can afford them. Luckily, there are more affordable solutions you can make all by yourself. These homemade structures are very effective and get the job done without making you spend a lot of money. They are not even so difficult to make – all you need is a bit of time and patience.
One of the most important aspects of a greenhouse is its ability to use it for propagation. These “propagation houses” can truly help you in the garden. Structures used for propagation are easy to make so you can have one in your garden in no time.
These structures, known as “hoop houses” are light yet strong enough to provide adequate attention. They don’t require much time or skills to make. Typically, they are made of a simple wood and PVC structure covered by some kind of a protection cover. These simple structures are very effective if providing a great place to grow your plants and starting a season much earlier. The temperature and other conditions inside of these structures are better than the outside ones early in the season, so this is a great way to start your plants earlier.
If you want to build a small, low-budget greenhouse, it’s very easy to do and it will give you so much satisfaction and prove to be a great help in your garden.
To build a greenhouse of your own, make sure to follow these steps:
The first step to a successful greenhouse project is to plan ahead and know what you want. Before you start building, you need to know what your requirements and wishes are. Determine several important aspects of your future greenhouse, such as size, budget, weather conditions and desired usage.
You need to know how many plants (and what type of plants) you want to grow. Your greenhouse has to be large enough to accommodate them all, even in the peak of the season. How do you want to plant: in containers or in the ground? Consider your weather: is is windy? Do you get a lot of snow? How much are you willing to spend for materials to build your greenhouse? These are just some of the questions you need to ask yourself before you start building your greenhouse.
Since this tutorial focuses on building a propagation house, most of the steps will show you how to do that (build a structure suitable for plant propagation). However, it’s easy to adjust the steps to suit different types of greenhouses.
Building a Foundation
The first thing you need to set is your foundation. It will serve to mark the borders of your greenhouse.
Determine a space in your garden for your future greenhouse and label it. After this, build a foundation on this alloted space. Rot-resistant lumber is the best, but it tends to be expensive. This is why you may use pressure treated wood. It can withstand years of use and damp conditions.
Setting the Construction
The next step is to build a construction for your greenhouse. PVC pipes tend to work great. Some of the best are 2″ PVC pipes you can easily get in stores. They will serve as sleeves for the hoops.
Set them into the ground at about 3 foot intervals inside of the wood foundation. They can be pounded into the ground with a mini sledge until they are flush with the top of the foundation. Make sure not to strike PVC directly – it will crack. Simply put a piece of the wood on top of the PVC pipe and hit with the sledge hammer.
The next step is to insert PVC bows to serve as the hoops for your construction. Their length will depend on the size of your greenhouse. They have to be long enough to reach from one side (and one sleeve) to the one on the other side of the foundation, leaving enough space so you can stand underneath.
A bit smaller PVC (1.25″) pipe works great for this. Insert them into the sleeves and then attach them with two 5″ carriage bolts going though both the wood foundation and the sleeve.
Making the Construction Stronger
To make the construction stronger, consider purlins. They will run perpendicular to the bows, providing sheer strength. You may install a center purlin above the bows to help shed snow and side purlins added on the underside of the bows. Attach these purlins with the help of 4″ carriage bolts.
Another thing to remember is to add hip boards. This is where the plastic covering will be attached to the greenhouse. Channel locks made to hold the wiggle wire are great because it means you won’t have to make holes in the plastic. Simply screw the channel locks into the hip board to secure them.
Another thing to keep in mind is to build end walls. They will go on the ends of the shorter sides of your greenhouse. Typically, one of the walls will be full while the other will have some sort of a door so you can enter the greenhouse. You can build them using various pieces of wood.
End walls tend to be tricky, because framing out rounded edges is not easy. A good way to go is to use a hole saw to cut ends of 2″x4″ where they contact the PVC bow. It will make a better connection. The connected end will bow to the end walls using a metal strapping.
Keep in mind that PVC and poly plastic interact on contact, degrading the life of the plastic. This is why it’s not a bad idea to create some sort of a barrier between them by adding a layer of duct tape. It can be time consuming but it will make your structure last for longer.
If you live in an area with a lot of snow, you will also have to build a support structure inside of the greenhouse because the hoops and plastic covering alone won’t be able to hold the structure. Depending on the size of your greenhouse, you can add one, two, three or more wooden braces to support the bows from the inside. You can secure them using metal strapping. You don’t have to build them on the ends – the end bows will be supported by the end walls.
The next step is to add plastic covering over the structure. The industry standard is a six-mil poly plastic and it works great. For the best results, make sure to stretch it over your structure on a warm day without much wind. You will typically need four people to do this efficiently, since all corners of the plastic have to be secured. Even more people make the job easier, so it’s something to consider.
Simply stretch out the plastic over the structure and secure it – this will keep it in place. It’s best to secure the plastic at the hip board and not the ground. It will help increasing the air flow in the greenhouse. This is beneficial for young plants when temperatures inside the greenhouse get too high.
You may also add black webbing to cover the plastic at each bow. It will help holding it town during strong winds. It will help holding the PVC roll up bars in place when they are down.
You can customize this basic structure to suit your specific needs. For example, you may need many tables for your plants, so make sure to build them inside the greenhouse. These tables are typically needed in a propagation house, but may not be vital for other types of greenhouses. Another thing to think about is your watering system. How will you get the water inside the greenhouse and what kind of a watering method you’ll use? This is another thing that will influence the inside setup of your greenhouse. Determine what you need inside of the structure and prepare it ahead of time.