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Large clear plastic bottle filled with layers of compost material
Home composting is a great way to turn kitchen and garden waste into nutrient-rich soil. If you have limited space, a large plastic bottle can become the perfect compact compost bin!

Helpful information

Timing: All year around

Where to do it: Indoors

Garden space: Balcony, Indoors

  • An activity you can do indoors all year round, with the whole family
  • The satisfaction of helping the environment by reusing plastic bottles, food and garden waste
  • Watch nature in action as the compost develops over weeks and months

Essential items

  • Large plastic drinks bottle (2-litre recommended)
  • Scissors
  • A small amount of water
  • Sticky tape
  • Waste items to put in your compost bottle (see below)

Optional items

  • Drawing pin
  • Compost maker / accelerator so you get compost quicker

Tools to make it easier

  • Specialist scissors

Start by gathering the tools for the task. Then, follow these steps to create your compost bottle with ease.

Step 1: Cut around the top of the bottle

Empty plastic bottle cut around 5 cm from the top leaving a hinge
An empty plastic bottle cut around the top leaving a hinge

You need to be able to get your compost items in and out of the bottle easily. To help cut around the top of the bottle, you may find it helpful to first make a small hole using a drawing pin. You want this to be around 10cm from the top. You may wish to widen this using a pencil. Using this hole as the starting point, carefully cut around the bottle with scissors.

Make it easier

Instead of cutting all the way around the bottle, you could leave a small hinge (see image above). This will make it easier to seal.

Step 2: Add compost layers

Large clear plastic bottle filled with layers of compost material
Layers of compost material inside the bottle

Good compost is a mixture of ‘brown’ and ‘green’ materials. Brown materials are woody, like twigs, and green are soft and green, like grass cuttings. Read our article on making home compost for more information.

Because a compost bottle is small, try to choose waste material you can cut into little pieces.

Ideally, layer your compost bottle as follows:

  • Soil (around 2-3cm)
  • Fruit and vegetable waste (2-3cm)
  • More soil
  • More fruit / vegetable waste
  • Small pieces of newspaper and cardboard

Repeat these layers until your bottle is almost full to the top. The very top layer should be soil.

Top tip

If you want your bottle to make compost faster, add compost maker / accelerator to the top layer of soil.

Step 3: Water, seal and wait

Large clear plastic bottle filled with compost material and taped shut
The finished compost bottle sealed shut with sticky tape

After you have filled your compost bottle, add a little water (around a tablespoon). The mixture wants to be moist, but not soggy.

Put the top part of the bottle back on and seal it shut using sticky tape. You could use a marker pen to draw a line level with the top of the compost, so you can see how much it goes down over time.

Make it easier

If you cut the entire bottle top off at step 1, you may find it fiddly to now put the top part back on. If so, hold it in place using a small piece of sticky tape. Then it will be easier to seal all the way around with a longer piece of sticky tape.

Place the bottle somewhere in your house that is not too hot or too cold.

Congratulations, your compost bottle is now ready to do its magic!

It will take several months for the materials in your bottle to break down into compost. You can check the bottle regularly and enjoy seeing what’s happening. You might want to take a photo every week or two to see what has changed.

Top tip

If your bottle compost is looking very slimy or very dry, you could open it up again and add some more material to help. Add paper or cardboard if it’s wet or more water if it’s dry.

Your compost will be ready when it has the look and texture of garden soil. Open the bottle and it should also smell a bit like garden soil.

You can now use your compost as part of small planting projects! One idea if you wanted to re-use more bottles is to create recycled bottle planters – see image below.

Bottom halves of plastic bottles reused as plant pots with green seedlings in them
A row of plastic bottle plant pots, with green seedlings growing in them

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