Worm Composting

Ever thought about going green with your organic waste?

In today’s garden wildlife blog, we will take a closer look at worm composting. Keeping worms in your garden or having a ‘worm bin’ or ‘wormery as it is also known, is an effective way to dispose of your kitchen and garden waste, turning it into nutrient-rich compost and a concentrated liquid fertiliser. The process is also professionally known as vermicomposting. It usually consists of two compartments; a large composting container above which houses the worms and compost, were you place your waste and the worms get to work, and a lower section that collects the liquid, which can be anything that will contain it like a bucket.

Starting a wormery is a relatively simple process, though there are a few key points to keeping an efficient wormery. You need to provide the right conditions, for instance worms prefer temperatures between 19 - 25oC, this is when they are most active. Once temperatures reduce to below 10oC their activity levels reduce. The location of the wormery is also important, if it gets too hot or too cold it can reduce the productivity of the worms, this is helped by keeping it in a sheltered spot or a shed. However, if neglected an odour can soon fill the space. Finally, they like a pH between 6.5 - 7.0 and dislike being waterlogged, as this restricts their air supply.

Our Assistant Warden has mastered it while being home in lockdown. In the image below, Simon built his own wormery from scratch, with his very skilled hands. As you can see, there is the upper main compartment where all the action happens, and the underneath compartment where the liquid is collected. This liquid is rich in nitrogen and potassium and can be used as a fertilizer on garden plants, although you may need to dilute it.  

Simon’s homemade garden wormery.

Be careful of what you put in your wormery, avoid putting in dairy products, meat, fat, grease and bones. This will attract unwanted pests, also don’t overload your wormery because it will slow the production down. Cooked and raw vegetables are fine, except for raw onions, leeks and garlic, fruit is also good to add, except for citrus peel. You can add tea bags, coffee grounds and bread, and newspaper, cardboard and garden waste, in small amounts. One key thing to remember is not to include the seeds from fruit and vegetable scraps, as they can germinate in the wormery.

There are various species of worm you can use for composting, these include the species Eisenia foetida, E. andreii and Dendrabaena veneta. These worms are smaller and darker red compared to earthworms (see image below), and are given various names including manure, red or tiger worms. These worms are inhabitants of decaying organic matter, whereas earthworms are soil dwellers. For this reason, earthworms are unsuitable for composting.

Eisenia foetida

The benefits of keeping a wormery in your garden is not only the management and environmentally friendly/natural disposal of your waste, but how it indirectly contributes to garden wildlife. The liquid generated by the wormery is generally rich in nitrogen and potassium and contains a host of other nutrients. This can be used to condition soil and provide a homemade liquid fertilizer, which you can use on your garden plants. In addition, once the organic matter is ready to use, i.e turned into a natural compost, it can be taken out and the process can start all over again with fresh waste. A healthy and diverse array of plants will attract invertebrates to your garden, which in turn will support other wildlife. Small mammals and birds will be attracted to the invertebrates, and larger mammals and birds of prey will also benefit from there being a steady food supply. It is indirect; however, it is important that all levels of an ecosystem are in place in order to support the different tiers.

If you want to learn more, the RHS provides key information about starting and maintaining a wormery at https://www.rhs.org.uk/advice/profile?pid=726.

Have fun composting your garden waste,