How to Build a Budget Greenhouse (and What to Put in it First!)


how to build a budget greenhouse

Buying a greenhouse can be expensive, so knowing how to build a budget greenhouse is a handy skill. We all know that being able to have fresh vegetables is something every gardener wants. Depending on where you live, with a greenhouse, you can grow and harvest virtually all year long. People are always happy to serve fresh veggies in the dead of winter and it’s amazing knowing you grew them yourself. There is just no comparison, especially when you see the wilted and decidedly unfresh options available at some grocery stores!

7 benefits of a greenhouse

There are numerous reasons why it is an excellent idea to have a greenhouse. Not only are you able to turn a sideline hobby into a full-time passion (obsession?), but you can also sell the spoils of your efforts. Whether you can spend the entire day in your greenhouse, or you simply have a few minutes here and there, a budget greenhouse is a great addition to your property.

If you are mulling over the idea of a greenhouse, or have never even considered it before reading this post, here are seven excellent reasons why you will want one of your own:

1. Have an all-season garden

Not all of us are lucky enough to live in tropical climates. Most of us must say goodbye to our gardens by October. When you are using a greenhouse, you can control the temperature. This means that you can start seeds and grow plants your actual climate will not permit. You can also start seeds much earlier than normal so that the seedlings are good and strong when it is time to put them outside.

For example, one of our readers in Canada has a 3-season greenhouse, and despite bitter temperatures outside at certain times of year, she can easily grow citrus fruits in her greenhouse. She brings the plants in for the winter in late November because the outdoor temperature is anywhere from 14 to -31 degrees Fahrenheit (-10 to -35 degrees Celsius) for at least three months. They go out again by the end of February, or mid-March at the latest.

2. Use the greenhouse for many things

You can use your greenhouse for a multitude of things. There is the option of growing seedlings, bulb plants, flowers, fresh vegetables, exotic plants, and house plants. It is also possible to grow a mixture of different things if you would like. You can grow just about anything in a greenhouse if you adjust the temperature/conditions accordingly!

3. Enjoy strong plant environments

By using a greenhouse, you can give your plants the exact conditions they need to grow. Whether you are growing herbs, veggies, or flowers, you want to see their growth enhanced. A greenhouse maintains the correct amount of humidity and warmth to simulate the natural growing conditions of your plants.

4. Get protection for your plants

It is easier to keep your plants safe in a greenhouse than it is outdoors in the garden. Bad weather can be hard on unprotected tender plants. Within the safe confines of a greenhouse, this is not an issue you need to worry about. Wildlife who would normally consider your vegetables a special treat are also unable to reach them inside. Additionally, it is less complicated to keep various types of pests from getting at your plants. If it does happen, they are straightforward to treat.

5. Grow flexibly

Regardless of changes in the seasons or weather you have the flexibility to grow the plants you want. Things that would cause problems for other gardeners, such as droughts, too much rain, or extreme temperature changes are not really a concern in a greenhouse.

6. Have everything in one place

You can build your greenhouse to suit your own needs. This means that you can implement a design that gives you storage for all your garden-related items. Instead of taking up space in the shed or garage, items you need can be stored here within easy reach.

7. Save money

If you go to the nursery every spring for flowers, you know how expensive they are. Once you have a greenhouse you can grow these same plants from seeds that cost a fraction of the price. After learning how to set up a greenhouse on a budget it may surprise you to see just how much you will save in the long run.

How much space will I need for my budget greenhouse?

When thinking of a greenhouse, many people see commercial greenhouses in their mind. Obviously, these take up tons of room that not everyone has to spare. The amount of space you are going to need will depend entirely on the size of the budget greenhouse you are planning. You can go as big or small as your space, and your budget, allows. The good thing is that you will also be able to add on to your finished space later if you require more room. One thing to keep in mind is that greenhouses that are very long will often require a concrete base to keep them secure. This will require more expense and work than a smaller structure.

What does a greenhouse usually cost?

Is it cheaper to build or buy a greenhouse? Purchasing a greenhouse can be cost-prohibitive for some people, especially if you’re looking at larger structures or ones with built-in technologies to help control light, temperature, humidity, and so on. Quality manufactured greenhouses can start at a couple of hundred dollars and go up into the tens of thousands. For this reason, it makes sense to find out how to setup a greenhouse for yourself to save money once that initial purchase is made. You will not be outlaying huge amounts of money, but you will still get the space and design that you need. Material choice will affect cost, but it is possible to build a greenhouse from items that you get for next to nothing. Consider looking at yard sales and auctions since you can often get very good buys.

The different types of greenhouses

There are many different types of greenhouses, meaning that you can choose what best suits your purposes.

1. Lean-to greenhouse

Lean-to greenhouses are attached to another structure for added support, such as a shed or the wall of your house. This makes them extremely strong. For gardeners who have smaller backyards, this style is quite appropriate. The best location is on a south-facing wall.     

2. Hoop house

The hoop style uses metal half hoops that are covered in fabric or plastic. They are quite distinctive and easily recognizable since most commercial growers use this type. They are unbelievably cheap to construct so they work well for budget greenhouses. The advantage to a hoop house is the height, allowing you to grow different taller varieties of plants.   

3. Gable roof greenhouse

With their simple design, a gable roof greenhouse is easy to build yourself. They get the maximum amount of light and give you the needed room to grow tons of plants. Height can vary but there is always enough room to move around comfortably. These are often sold as DIY kits.

4. A-frame greenhouse

The A-frame is simple to build yourself and popular with greenhouse enthusiasts.Even a person with no experience in building can put one of these together. They do not have the maneuverability of other styles due to the shape, and the airflow inside is not always constant because of the tight corners.  

5. Sawtooth greenhouse

Sawtooth greenhouses are slightly more intricate than other styles. The highest point of the house features vent openings that allow fresh air to enter and warm air to escape. These are more costly to construct than the simpler styles.    

6. Shade house

Most greenhouses want to let in as much sunlight as possible. This is where shade houses differ. They are used to grow plants that need protection from the strong rays of the sun. Instead of being made from plastic or glass, shade houses use cloth. The cloth comes in different colors and that allows you to customize how much sun your plants get. Plants like orchids thrive in shade houses.  

7. Dome greenhouse

Although these are complicated to build, dome greenhouses are energy-efficient and long-lasting. Triangle shapes are used instead of traditional squares or rectangles. The best part of this type of greenhouse is that light enters from every direction.     

Greenhouse components

Before you start building your greenhouse, you will need to secure the materials you are planning to use. Start by checking with friends and family members to see if they have any glass, wood, or plastic they want to get rid of that you could possibly use. Once people start rummaging around in their garages and sheds it is amazing what they are able to find! Materials like this should cost you almost nothing so your budget greenhouse is right on track. Try using the barter system. Offer to provide some fresh veggies in lieu of cash to lower your costs even further.

Greenhouse foundation

If you are putting down a foundation, you will need cement slabs, or something similar. These can be purchased brand-new, or you can check online sales sites. There are often people who wish to get rid of items like these for almost nothing if you are willing to go and pick them up. Sometimes local construction companies are also willing to help and will sell you leftover materials below cost. Alternatively, you can use wood to make a mold in the size that you need and then pour the concrete yourself. If you don’t fancy using concrete, you could also use gravel over the earth but you might want to think about putting down a weed barrier first.

Siding

Next, you will have to decide on glazing or siding material. You want to use something that will be able to stand up to inclement weather and hold the heat in. Glass is a popular choice and it is relatively easy to find older windows at low cost. If you choose to forgo glass, then you will need some type of plastic, whether it be polycarbonate, fiberglass, or polyethylene film. For people who live in year-round warm areas where insulation is not such a concern, plastic panels are another option that can be used. The major benefit of using plastic is the fact that it does not shatter the way glass can.

Framing material

Framing material will be another decision. To avoid constant maintenance, it is better to use something that will stand up to heavy winds and rain. The siding will also affect the framing choice. If you have a heavy siding, then a heavy frame is required to provide the proper support. Wood is a popular material and many gardeners have it just lying around the property. However, galvanized steel, aluminum, and even PVC will hold up much better over the long-term.

Additional components like heating and water elements must also be given some thought. What you will require in this regard will again depend on the area you live in. Shelves, or the materials to build them, will also need to be purchased.

How to build a budget greenhouse – exterior considerations

Building the exterior of a greenhouse is the easy part. It literally requires that you build a frame, cover it, and add a door. If you do not want to go to the trouble of adding vents, you can get around this by using screened doors at both ends. That same reader in Canada we mentioned above has a venting system but because of the direction her greenhouse faces it is usually more effective just to slide the windows up on the doors. Since they have screens, she is able to keep out birds and insects, and the breeze that flows through keeps the temperature from increasing too much. The odd time when it gets too cool, it is a simple matter to close the windows either fully or partially.

For budget greenhouse farming, you want to think about location and structural elements as ways to save money.

Location, location, location

Now that you have decided how large you want your greenhouse to be, and what style you like, you need to pick a location before you start construction. With a freestanding greenhouse, you want to put it where it will receive the greatest amount of sun. As you are mapping it out, consider the trees you have planted nearby. At certain times of the day, they are going to cast shadows and you do not want this to affect how much sunlight your plants receive. Thirty feet (approx. 9 meters) away from trees is a good distance to aim for. If there is a possibility that you may want to add on to your greenhouse sometime down the road, make sure you will have room for this as well.

Another factor to consider when deciding on the placement of the greenhouse is which direction you normally get wind from. If you live in an area where the winds predominantly come from either the east or west, have your sidewalls facing north and south. This way you will not put unneeded stress on the walls when powerful wind gusts sweep through. Likewise, face your walls east and west if your winds are from the north and south.

Structural elements

For a traditional structure, greenhouses should have the frame, both end walls, sidewalls, glazing, and rafters. If you plan on running your glazing all the way to the bottom, save yourself the heartache and install a kickboard. Depending on how large the greenhouse will be, cross braces may also be needed. After doing all that work, the last thing you would want is to have your greenhouse collapse in the middle!

If you have chosen to use some type of plastic sheeting or film for your covering, make sure that it is pulled taut. When air is able to work its way through and enter loose spaces, the covering can easily rip once the wind gets a hold of it. Taking the time to ensure it is firmly secured will save you both time and money down the road.

How to build a budget greenhouse – interior considerations

When the greenhouse is built, the actual use for it will need to be carefully considered. What type of plants are you planning on growing? If your answer is potted flowers, more shelf space than floor space will be required. For a gardener more interested in growing veggies like carrots and tomatoes, ground space is essential. If you plan on growing some of the same crops every year, you can build some raised beds for root vegetables. A foot high is more than sufficient for vegetables like carrots, turnips, parsnips, and beets.

Vertical growing

One of the best ways to maximize the growing space inside your greenhouse is to plant crops that can grow vertically. Some of the best ones for growing like this include cucumbers, zucchini, string beans, and peas. The yields that you get are incredible for the small space they occupy! This works especially well when you have a center aisle and crops planted on both sides. It also makes weeding and harvesting simple.

Temperature variation

You will also need to grow plants that like the same temperature. If you put both heat and cold-loving plants together, one group is not going to fare well. For those interested in growing plants from different temperate zones, you could plan to section off the interior of your greenhouse. For example, place all your plants that prefer cooler temperatures in one area. You can simply wall it off with plastic sheeting to avoid overheating them from internal heat sources.

Storage and shelving

Leave space to build storage shelves. All the tools you normally use in the garden are used inside the greenhouse. Things like hoes, shovels, and trowels need to be stored securely so you do not accidentally trip on them. You will also need a place to keep plant pots, seeds, compost, watering cans, gardening gloves, and the various other items you deem essential. When shelves are utilized correctly, the amount of space inside your greenhouse is used to its best advantage.

Water and irrigation

When the budget allows, you may want to set up some type of irrigation system. You can make various ones yourself and there are numerous instructions to be found for free on the internet. They are also available to be purchased but they are often expensive. Many people building a budget greenhouse will set up a rainwater collection system inside the greenhouse using a barrel. You can use piping from the eavestroughs that runs into a barrel mounted on a table inside. You can also attach a tap to the bottom of the barrel and connect a hose to it. Gravity forces water through the hose when you turn the tap, which makes watering the greenhouse a breeze. This way you can also make sure that nothing gets over or underwatered. There is also water handy for cleaning or mixing up homemade fertilizer or pesticide solutions.

Heating the greenhouse

Whether you will need to add heat depends on how cold your winter season gets. There are several options for what you could use. Propane heaters or electric heaters are popular choices because you can control the heat output. Pellet stoves can also be used if you find the expense justified. Traditional wood stoves are another option for large spaces, but you will end up with extreme heat variations.

Personal additions/workspaces

When it comes down to it, the way you set up your interior depends mostly on personal preference. There is no right or wrong way to do it. One other item that you will probably want to include, though, is some type of workbench and table. These are beyond useful for planting seeds, transplanting, and repotting. By using a bench, you will avoid the backache that comes from bending over for long periods of time! These can be built to your exact specifications so that your comfort is maximized.

Starting a greenhouse the right way

Those new to the world of greenhouse gardening should start off their first year in March or April. By this time, the below zero temperatures should have passed, and it still gives you plenty of time to germinate your seeds. However, learning how to start a greenhouse properly takes some planning.

Sketch your space

Before you start buying seeds and planting, sit down and draw out a rough sketch. Include all the plants you want to have and where you think you will put them. Once the sketch is completed, take a good look at it. Does it make sense? Do you have tall plants growing in front of shorter ones? Are plants with a shade preference right in full sun? Do you have enough space for plants as they grow? When should each type of plant be started?

You want to your greenhouse to be successful, so taking the time to plan thoroughly will give it a great chance. If you are concerned about how to setup a greenhouse on a budget, this planning will help you minimize unnecessary spending, too.

Figure out planting timelines

As mentioned previously, planning is key so figure out which plants need to be started early. Obviously, these are what will be planted first. Something that takes 150 days to harvest needs to be planted much earlier than a crop that only needs 65 days. If some of them are taller than others, make sure your tall plants are at the back. When greenhouse walls face north and south, all tall plants should go at the back of the north wall. If the walls face east to west, tall plants should go at the back of the east wall. This way they will not cast shadows over shorter plants during crucial sun gathering hours.

Many plants do better when they are grown from seed in small seed cell pots and then transplanted into the ground. It does not make much of a difference if you are keeping the plants in the greenhouse until harvest. If you are planning on using your garden space, vegetables like tomatoes, cucumbers, and squash, for example, have a better survival rate when they have a chance to form sturdy seedlings before being planted. Weather can really wreak havoc on seedlings just emerging from the ground.

Whichever way you choose to start your seeds, keep them warm and moist during germination. Take care not to overwater seeds or they could rot. You do not want them to dry out either so keep a happy medium. If the seeds you are growing are especially small, like lettuce or celery, mist them instead of using a watering can.

What are the best plants to start a greenhouse with?

Even with the most basic budget greenhouse, growing plants to be proud of is an easy task. For the gardener just starting out, some plants basically grow themselves. Give them the correct temperature, amount of water, space, and sun, and these listed below will give you no trouble at all!

  • String beans
  • Peas
  • Carrots
  • Lettuce (bonus here because it keeps growing even when you keep cutting it down)
  • Cucumber
  • Radish
  • Strawberries
  • Green onions
  • Tomatoes (planting all of these will give you the ingredients for a daily salad!)

To ensure you have a steady supply throughout the season, veggies like peas, string beans, and radishes should be succession planted. If you plant new seeds every two weeks you will constantly be able to harvest without running low. (Psst… want to read more about the best crops for greenhouse farming? Check out our article on that subject here!)

What is your plan to build a budget greenhouse?

Isn’t it tempting to have a greenhouse of your own? Now that you know how to setup a greenhouse on a budget and plan the first plants properly, there is no reason to put it off! If you are concerned about having more than you can use, do not let that stop you. There are always people clamoring for fresh vegetables and locally grown plants. You could set up a roadside stand or sell some at farmer’s markets. When it comes to veggies, most of them freeze very well. Those that do not can often be canned and stored in the cellar. There is work involved with having a greenhouse, but anything worth having takes work. And a greenhouse is truly worth having for all the rewards you will receive from it!

Alice

Alice is a writer who grew up on a beautiful homestead in rural Old England. She now lives in New England with her fur babies and is on a mission to return to the land for a simpler, greener, and all-round kinder existence.

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