How composting garden waste helps your patch and the planet

Infographic showing Revive’s composting process: green waste, shredding, turning, screening, and final compost product.

Ever wondered what happens to your garden waste after it’s collected in Somerset?

It’s not just thrown away – it’s transformed into high-quality compost, helping local gardens and farms thrive while cutting down on recyclable materials ending up in Energy-from-Waste (EfW) facilities.

At Biffa’s Bridgwater and Castle Cary sites, garden waste collected from households and recycling centres is processed into compost. Only pure green waste makes it in – think grass cuttings and plant trimmings, not food scraps or plastics. The process starts with shredding and piling the waste into big heaps, or ‘batches’, each weighing between 400 to 500 tonnes.

The composting journey takes about 12 weeks and includes 2 main phases: a 2-week sanitisation, where heaps are kept hot enough to kill any nasties, followed by a 10-week stabilisation with regular turning and checking to make sure the mix is just right. Temperature and moisture are carefully monitored throughout to keep everything on track.

The compost is made to meet strict PAS100 standards, which means it’s tested regularly in accredited labs. Samples are checked for things like pathogens, plastics, stones and heavy metals, as well as for how well plants grow in it. Only compost that passes all these checks leaves the site, so you can be confident it’s safe and effective.

Once ready, the compost is screened into different grades. Finer compost is perfect for gardens and allotments, while coarser batches go to farms and larger green spaces. Remember, this is a soil conditioner, not a multi-purpose compost, but it’s packed with organic matter, slow-release nitrogen, potash, and a bit of phosphate. Over time, it boosts soil health, helps your plants grow, and even reduces the use of peat in gardening – good news for Somerset’s environment.

If you’d like to get your hands on some, look for Biffa’s ‘Revive soil conditioner’ at your local recycling centre or email ReviveCompostSales@biffa.co.uk to find out about buying in bulk or by the bag. It’s a simple way to give your garden a boost while supporting a more sustainable Somerset.

All garden waste in Somerset can be recycled for free at any of our recycling sites, or for convenience a paid-for subscription for a kerbside garden waste collection can made online.