Composting is great for the environment and for the garden, but having the wrong balance of materials can create problems, such as:

A dry, cold pile that doesn’t reduce

Soggy, muddy compost that smells terrible

A swarm of animal or insect pests around the pile or bin

The following are some troubleshooting tips to avoid or address these composting problems.

The compost is dry and cold

Compost should get smaller and generate heat. It should be moist (like a damp sponge), though not muddy and waterlogged. Add water if it’s too dry and mix in more nitrogen-rich material (kitchen scraps, fresh-cut grass, etc.). If using an open compost pile, covering it to prevent moisture loss or relocating it to a less sunny spot can be helpful, particularly if you live in a hot, dry region.

The compost is only moist and warm in the center of the pile

If the pile is too small, it may have a warm, moist center but the outer portion will be cold and dry. Add more material and mix it in well to increase the size of the pile.

The compost is cold and smells sweet

If the compost is cold and sweet-smelling, add some fruit or vegetable scraps, organic fertilizer, or fresh-cut grass to add nitrogen. Turn the pile to mix in the new ingredients, and add a thin layer of soil on top.

The compost smells like rotten eggs

A rotten-egg smell indicates that the compost is not getting sufficient air. Stir or turn the pile to aerate it and break clumps apart. Then add a thin layer of soil on top. Adding some dry, carbon-rich material (such as straw or dried leaves) can help to keep the pile drier and more aerated.

The compost smells like ammonia

This occurs when compost has too much nitrogen-rich or “green” material (kitchen scraps, wet grass, etc.) and not enough carbon-rich material. In this case the pile will likely be soggy and muddy. Add some carbon-rich material such as dry leaves, turn the pile over, and add a thin layer of soil on top.

The compost is attracting animals

Meat scraps, fatty or oily foods, bread, cake, pasta, and rice will attract pests, so avoid adding these materials to your compost. Use a lidded container or wire mesh around the base of an open compost pile to discourage wild animals. Many pests can also be discouraged by adding pet hair to the compost. In addition, turning the pile regularly to release trapped heat can reduce the pile’s attractiveness as a nesting site for rodents, which may burrow in seeking warmth during the colder months.

The compost is attracting flies

If flies are a problem, burying kitchen wastes under a layer of dry materials can reduce the compost’s attractiveness to insects. If you’re collecting material in the kitchen, keeping it in a covered pail in the freezer or refrigerator is recommended.

There are slugs and snails in the compost

Many people believe that slugs and snails in the compost are a problem, but they’re actually useful in helping to break the materials down. In addition, the smorgasbord of favourite slug and snail foods in the compost bin helps to keep them away from garden plants they’d normally attack.

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