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How to Make a Greenhouse: Design Choices, Plans, Materials and More

So, you’re thinking about how to make a greenhouse for your garden, or you already have a greenhouse, and you’re looking for some information on using it better. You’re in the right place!

Garden greenhouses can be very satisfying or very frustrating, depending on whether the greenhouse you build is a good fit for what you need – or not.

Greenhouse Designs

There is a wide range of different designs of greenhouse, and then there are different materials that you can build the designs out of. Basic designs include lean-to or freestanding structures, temporary or permanent, built from wood, metal or plastic, and glazed or covered with glass or plastic.

The greenhouse design you choose depends on what you want to do: extend your season a little at each end? Grow food in winter (what kind of food?)? Propagate tropical plants? The more heat and light you need through the cold months, the more solid and permanent your design needs to be, and the more expensive it will be to build and run.

You also have choices about how you create your greenhouse. Will you design and build it yourself, get plans from some where and build it yourself or have someone build it, or will you use a greenhouse kit?

Greenhouse Kits

One excellent way to get into the world of garden greenhouses is to buy a kit. All the design work is done for you, you just have to pick one that fits your needs. In most kits the required parts and hardware are all included and they are all ready sized and shaped for you to assemble them.

Greenhouse Plans

If you’re intending to build your own greenhouse, or have one built for you, you’ll need plans. Although you can draw up your own plans, if you don’t have experience doing this kind of work you may do better to obtain ready-drawn plans for a greenhouse that fits your needs. You can find free greenhouse plans in many places on the Net and in books and magazines, and also buy them. If your greenhouse is to be a permanent structure you may need to have your local building department approve the plans and issue a permit.

Build Your Own Greenhouse

So – you’ve decided on the design, got a kit (or plans and materials), and you’re going to build a greenhouse yourself. Building a greenhouse may call on any or all of the following skills:

  • Digging foundations
  • Preparing formwork
  • Working with concrete
  • Laying bricks or concrete block, or pouring concrete
  • Building wood frame walls
  • Assembling framing for glazing
  • Installing glazing
  • Roofing
  • Weatherproofing
  • Installing electrical wiring
  • Installing plumbing
  • Painting

Cheap Garden Greenhouses

If a full size, traditional glazed greenhouse is beyond your budget, you have several possible ways to proceed.

One rather traditional one is to collect used windows and build your greenhouse from them. I’ve seen some quite attractive greenhouses (in a wacky kind of way) built like this.

You can also build a PVC pipe and plastic sheeting greenhouse, called a hoop house, high tunnel or polytunnel. This uses heavy duty PVC plumbing pipe to create hoops, and UV-stabilized greenhouse plastic sheeting to form the glazing.

The tunnel part is very easy to build, but the ends, doors and ventilation are a bit more challenging. Most awkward of all is to arrange roll-up sides which will stay down in a high wind.

A big advantage of a polytunnel is that you can have a much larger greenhouse area for a very reasonable price compared to a traditional framed and glazed greenhouse. The big disadvantage is that it’s not as long lived – the plastic needs replacing every 2-5 years depending on your weather conditions.

Furnishing your Greenhouse

OK, you’ve got a greenhouse. Now what? If you plan to grow in ground level beds, you may be able to go ahead with soil prep and planting. Otherwise, you need somewhere to grow – perhaps raised beds, perhaps greenhouse benches to place pots on – and you may need a variety of greenhouse supplies like heaters, fans, vent mechanism, shading materials and on and on. Specialized greenhouse supply dealers carry an amazing variety of items, many of which you don’t know you need until you see them.

Growing in your Greenhouse

This is what we were aiming for in the first place, when we decided to make a greenhouse, and it turns out to be very much the same as growing outside in the garden, as well as very different. Some of the special issues with greenhouse growing include:

  • temperature management
  • ventilation
  • watering
  • pollination
  • fertilizing
  • vandalism
  • lighting
  • growing supports
  • pest control
  • disease control
  • structure maintenance

Future posts will go into more detail on all these topics.