How to choose a compost bin
Before choosing a compost bin, think about how much waste is produced from your garden and what you want to compost from your home, then consider the following points and choose a model to match.
Where will it go? Location is likely to influence your choice of bin. A site in full or part shade is best for successful composting. Most bins need to be placed on soil to achieve good drainage and boost microbial action, but the Aerobin and Hotbin must be on a level, hard surface. If you want a cheaper compost bin but only have hard surfaces, look for a model with the option of a base plate to create good drainage and aeration.
Which design is best? If you only want or have room for a single bin, choose a design where the finished compost can be easily harvested from the bottom so you can keep filling from the top. This applies to all the plastic composters in our trial.
How fast is compost produced compared with the work involved? Composting in traditional (non-insulated) bins takes 6-12 months on a ‘fill and forget’ approach. You can speed up the process by emptying out, turning and refilling to incorporate air and increase the temperature, but this takes time and effort. A lid or cover will help retain heat and moisture, and keep out excess rainfall, so cover open bins with a piece of plastic or old carpet.
Material and thickness also influence compost speed by retaining more heat. Wood is a good insulator while thin plastic has the poorest qualities. Highly insulated or ‘hot’ composters are the most expensive but also have the potential to make compost in just a few weeks as the composting process is faster at higher temperatures. This type of bin suits a little and often mode of filling: note the Aerobin and Hotbin require a weekly supply of pre-mixed waste to work at their most effective.
What can you compost? Most garden material is compostable, including grass clippings, annual weeds, leaves of perennial ones (not roots, they’ll keep growing) and soft prunings. This green material would become airless and soggy on its own so, for effective composting, mix with around the same amount by volume of browns such as chopped-up woody stems, brown cardboard and non-shiny paper. Raw vegetable scraps, teabags, coffee grounds and cut flowers can go in any type of bin, but cooked food, meat and fish must only go in an enclosed vermin-proof design.
What do you get for the money? Consider the length of warranty, particularly with wooden bins and the eco credentials of the bin, which can vary – some are made from FSC wood or totally from 100% recycled plastic while others contain none.