Here’s a great practical project for the whole family – turn used plastic bottles into a greenhouse, and then enjoy the chance to grow some of your own food once you’ve finished. Some of the heavier construction work is probably going to be adults-only – or older kids at least – but there’s still plenty that can be done by smaller children and the basic idea can be adapted to make everything from a small cold frame to a really sizeable greenhouse. It’s a particularly good project for schools or large groups – but even with dozens of willing hands, it’s a big undertaking, so it’s not going to get done in an afternoon!
Clearly, the first thing to do is collect the bottles. Two-litre clear plastic bottles are the best to choose – but remember, if you’re planning on a full size greenhouse, you’re going to need 1,000 or more, so don’t waste any time getting started.
The bottles will need to be washed, have their labels removed, tops discarded and then have their bottoms cut off with a pair of scissors, in readiness for use. A little appropriate supervision may be called for here, since quite aside of the scissors themselves, the cut surfaces can be surprisingly sharp too. It’s probably a good idea to do this as you go along, rather than wait until you have the whole lot to do at once, which is probably going to be a bit of a daunting task, not to mention tiring!
Preparing The Frame
The basic structure of the greenhouse is made up from rows of bottles, threaded onto garden canes and then fixed to a wooden frame, made from lengths of 2-inch x 2-inch timber. How large the frame needs to be obviously depends on the size of the greenhouse you’re wanting to make.
It works like this. The bottles are stacked one inside another, with a garden cane running through the gap where the cap used to be, to produce a long plastic tube; the last bottle in the line is turned round to face in the opposite direction, so that you have a bottle neck at each end. Once completed, each one is fixed to the frame using fencing staples, or nailed through holes drilled in the cane. Keep on adding the bottle tubes until the whole thing is covered to form one of the panels of the greenhouse.
Building The Greenhouse
The greenhouse door can be very easily made as a separate smaller frame, with hinges attaching it to the rest of the front wall panel and a simple flat or pent-roofed design is probably the easiest choice for a first project. If you add a length of guttering and a water butt when you’ve completed the construction, you’ll be well set up to harvest the rain to help you water the plants you’re eventually going to be growing.
To keep the whole thing anchored to the ground, four 4-inch square fence posts should be driven or cemented into the ground at the corners of where the greenhouse is to be sited. Then the individual frames are simply screwed onto these posts once the cement has set, and that’s pretty much your greenhouse ready for use.
The quantities of materials you’ll need obviously varies with the size and shape of greenhouse but as a general guide, for a flat-roofed one that’s around 8ft x 6ft x 6ft high you’ll need:
- Plastic Bottles – 1,600
- 6ft garden canes – 150
- 4-inch square x 8ft fence posts – 4
- 2-inch square x 6ft (side, front and back frames) – 12
- 2-inch square x 8ft (side and roof frames) – 6
- 2-inch square x 7ft (roof frame) – 2
You’ll also need a supply of hinges, suitable screws, fencing staples and cement.
Making your own greenhouse from plastic bottles is a great way to turn “waste” into something really useful. It takes a bit of effort, certainly, but the end result is a very eco-friendly building that should allow you to grow your own fruit, vegetables and garden plants for years to come – and at the fraction of the economic or energy costs of a traditional glasshouse. All from a few drinks bottles; now that can’t be bad!