Do worm bins smell? | How to stop a worm bin from smelling

A healthy worm bin will smell like sweet soil or have no smell at all. When a worm bin is kept in balance the worms will be able to break down food scraps rapidly into worm castings which resemble soil. This soil improver is fantastic for your garden and will help you to save water and improve plant growth.

This article will explore why a worm bin could smell and what you can do about it. There are some easy steps to follow for keeping a worm bin balanced with moisture, food for the worms and soil bacteria.

Why does my worm bin smell?

Here are the top reasons why a worm bin could smell so you can work out what is happening to your bin at home. See if any of these might be the reason why your bin is smelling.

Too much food

Adding too many food scraps to a worm bin is the top reason why it can smell. Too many food scraps will take too long for the worms to eat and it can rot. Rotting food can quickly smell acidic and sour.

Feeding the right amount of food to your worms is a bit of an art. Worms will be able to break down more food in the warmer months so you will need to adjust the amount up or down depending on the season.

Start by adding 1-2 small handfuls of food scraps every 3 days and adjust the amounts up and down for your worms. The scraps should be eaten by the worms and soil bacteria within the week to avoid smelling and going moldy.

Too much water

Too much water is another cause of a smelly worm bin. Heavy rain, water from your hose or water that comes out of the food scraps can all encourage mold growth. Worm bin bedding should have moisture but should not drip if you squeeze it out.

For worm bins that are too wet, reduce the amount of food scraps added particularly fruit. Add an extra layer of worm bedding to absorb the water. Sugar cane mulch, straw or coconut coir can be added to the top of the worm bin or mixed in gently.

If too much water from rain is the problem, a small tarp can be placed over the top of the worm bin during a downpour. This will prevent the excess water from getting into the worm bin and soaking it through.

Remember to remove the tarp after heavy rain to allow air flow again. A tarp can heat up a worm farm quickly when the sun comes out so only keep it on temporarily during heavy rain.

Air flow

Lack of air flow can cause a smelly worm farm. Lack of air movement will mean that the worm farm can stay wet, the worms will lack oxygen so can slow down the breakdown process and they may not breed as quickly.

Worms that are struggling with a lack of air flow will slow down their digestion of food scraps and they will not breed well. A growing colony of worms is what is needed to keep the worm farm breaking down food scraps quickly and avoiding the smell.

How to stop a worm bin from smelling

The top ways to stop a worm farm smelling include regular and small amounts of food, lids and blankets and keeping an eye on the drainage.

Food

Working out the right amount of food to give to your worms is an art rather than a science. Start small and add a handful of food scraps every few days and start to add more when you see the food disappear.

As you see how quickly your worms can break down the food you can adjust the amount up and give them more as you go. The worms will breed quickly in a healthy worm bin so will be able to digest more and more food as time goes on.

I have moved from a few handfuls of food per week to almost double this after 6 months of my worms breeding. My worm bin is now full of worms who break down food scraps within a few days.

Lids and blankets

Worm blankets are an important addition for your worm bin. They will help to regulate the amount of water in the bin as the natural fibers absorb and release excess water. They can help to keep the moisture level perfect and prevent flies from coming in and landing on the food.

A lid on your worm farm will also help to keep the perfect balance of air flow, water and protection for your worms. Worms love a dark space so will more effectively digest the food if they are covered. Worm bin lids also help to prevent extra water coming in from light rain.

Healthy worm bins will be moist but not dripping wet. The combination of darkness, moisture and food will keep your worms happy and digesting food scraps quick.

Drainage

Good drainage on your worm farm will also help to keep the moisture balance to prevent it from smelling. For pre-made worm farms, make sure the bottom tap is opened and the worm juice is drained regularly.

Many worm farmers including myself like to keep this tap permanently open and place a bucket or bowl underneath. This will allow excess water to drain out and prevents the risk of forgetting and the bottom layer filling up.

Do worm bins smell? | Summary

A healthy worm bin will not smell bad but have a sweet, earthy smell from the broken down organic matter. This humus can be mixed through your garden for an extra nutrient boost and to improve the soil structure.

The combination of the food scraps you give the worms and their digestive process will give you garden gold. Find the perfect balance of moisture, food and air flow and your worm farm will not smell.

Happy worm farming.