Mastering Moisture: The Key to Perfect Compost

February 21, 2021 in environment, recycling

Article summary and Key takeaways: Composting is a great way to reduce waste and create nutrient-rich soil, but it’s important to maintain proper moisture levels. Signs of wet compost include a foul odor, excessive moisture, and the presence of pests. Overwatering, lack of aeration, and an improper balance of green and brown materials can cause wet compost. Wet compost can lead to slow decomposition, nutrient loss, and an increased risk of disease and pests. You can determine if your compost is too wet through the squeeze test, visual inspection, and smell test. Solutions for wet compost include adding dry materials, turning or aerating the pile, and adjusting the compost bin or tumbler. To prevent maggots, maintain proper moisture levels and avoid adding certain foods. Soggy compost can still be used, but it may have reduced nutrient content. If compost gets rained on, cover it and manage excess moisture. Allowing compost to dry out can have benefits, but excessive drying can slow down decomposition. Overall, maintaining a balance between moisture and aeration is key for successful composting.

Is Your Compost Too Wet?

Composting is a wonderful way to reduce waste and create nutrient-rich soil for your garden. However, in order to achieve successful composting, it is crucial to maintain proper moisture levels in your compost. Too much moisture can lead to a range of issues, including slow decomposition, nutrient loss, and an increased risk of disease and pests. In this article, we will explore the signs of wet compost, the causes and effects of excessive moisture, and provide solutions for managing and preventing wet compost. Let’s dive in!

Signs of Wet Compost

Foul Odor

One of the first signs that your compost may be too wet is a foul odor. If your compost smells like rotten eggs or ammonia, it is likely that excessive moisture is present. This odor is caused by anaerobic decomposition, which occurs when there is not enough oxygen in the compost pile.

Excessive Moisture

Another noticeable sign of wet compost is the presence of excessive moisture. Your compost pile should be moist, but not dripping wet. If you squeeze a handful of compost and water drips out, it is a clear indication that your compost is too wet.

Presence of Maggots or Pests

Wet compost can attract unwanted pests such as maggots, flies, or slugs. These organisms thrive in moist environments and can disrupt the composting process. If you notice an infestation of maggots or an increase in pest activity in your compost, it is a strong indication that the moisture levels need to be addressed.

Causes of Wet Compost


Overwatering is one of the most common causes of wet compost. It is important to remember that compost needs moisture to decompose properly, but too much water can suffocate the beneficial microorganisms responsible for breaking down organic matter. If you are adding excessive amounts of water or if your compost pile is located in an area prone to heavy rainfall, it can lead to a soggy compost pile.

Lack of Aeration

A lack of aeration in your compost pile can also contribute to excessive moisture. Proper airflow is essential for the composting process as it helps to maintain the right level of moisture and provides oxygen to the microorganisms. If your compost pile is too compacted or if there is insufficient turning or mixing, it can lead to poor aeration and the accumulation of moisture.

Improper Balance of Green and Brown Materials

Composting requires a balance of green and brown materials. Green materials such as kitchen scraps, grass clippings, and fresh leaves are high in nitrogen, while brown materials like dried leaves, straw, and wood chips are high in carbon. If your compost pile has an imbalance of these materials, such as an excess of green materials, it can contribute to excessive moisture. The high nitrogen content in green materials can create a wet, slimy compost pile.

Effects of Wet Compost

Slow Decomposition

Excessive moisture slows down the decomposition process in your compost pile. The lack of oxygen and the waterlogged conditions create an environment that is less favorable for the beneficial bacteria, fungi, and other microorganisms that break down organic matter. As a result, the decomposition process takes longer, and your compost may not reach the desired maturity level in a reasonable timeframe.

Nutrient Loss

Wet compost can lead to nutrient loss. Excessive moisture can cause nutrients to leach out of the compost pile, making them unavailable to your plants. This can result in nutrient-deficient compost that does not provide the desired benefits to your garden.

Increased Risk of Disease and Pests

The presence of excessive moisture in your compost can create a breeding ground for pathogens and pests. Anaerobic conditions favor the growth of harmful bacteria and fungi that can cause diseases in your plants. Additionally, the wet environment can attract pests such as slugs, snails, and flies, which can damage your compost and spread diseases to your garden.

How to Determine if Compost is Too Wet

Squeeze Test

The squeeze test is a simple and effective way to determine if your compost is too wet. Take a handful of compost and squeeze it tightly in your hand. If water drips out of the compost, it is a clear indication that it is too wet.

Visual Inspection

Visually inspecting your compost can also give you insights into its moisture levels. Wet compost will appear dark and compacted, with a slimy texture. It may also have a shiny or greasy appearance.

Smell Test

Another method to determine if your compost is too wet is through the smell test. If your compost has a strong foul odor, like rotten eggs or ammonia, it indicates the presence of excessive moisture and anaerobic conditions.

Solutions for Wet Compost

Adding Dry Materials

If you have identified that your compost is too wet, the first step is to add dry brown materials such as dried leaves, shredded newspaper, or straw. These materials will absorb excess moisture and help to balance the moisture content in your compost pile. Avoid adding additional green materials until the moisture levels are under control.

Turning or Aerating the Compost Pile

Turning or aerating your compost pile is crucial to improve airflow and reduce moisture. Use a pitchfork or compost turning tool to mix the materials in your compost pile thoroughly. This will introduce oxygen and help to dry out the wet areas. Aim to turn the pile at least once a week, or more frequently if needed.

Adjusting the Compost Bin or Tumbler

If you are using a compost bin or tumbler, you can adjust the moisture levels by modifying the ventilation or drainage system. Ensure that your compost bin or tumbler has sufficient drainage holes to prevent water accumulation. Additionally, you can open the lid or remove the cover to increase airflow and encourage evaporation.

Dealing with Maggots in Wet Compost

Prevention Methods

To prevent maggots from infesting your compost, it is important to maintain proper moisture levels. Avoid overwatering and ensure proper aeration by turning or mixing your compost regularly. Additionally, avoid adding meat, dairy, or oily foods to your compost pile, as these can attract flies and maggots.

Removing Maggots from Compost

If you discover maggots in your compost, you can manually remove them by hand or with a shovel. Place the maggots in a sealed container or bag and dispose of them in the trash. Avoid using pesticides or chemical treatments, as these can harm the beneficial organisms in your compost.

Can Soggy Compost Still be Used?

Risks and Considerations

Soggy compost can still be used, but it may not provide the desired benefits to your plants. The slow decomposition and nutrient loss associated with wet compost can result in an immature product with reduced nutrient content. It is important to assess the quality and maturity of your compost before using it in your garden.

Ways to Salvage Soggy Compost

If your compost is too wet, you can salvage it by allowing it to dry out and then reconditioning it. Spread the compost in a thin layer under direct sunlight or in a well-ventilated area. Turn the compost regularly to promote drying and to prevent the growth of harmful bacteria. Once the compost has reached a suitable moisture level, you can reuse it in your garden.

Is it Okay if Compost Gets Rained On?

Effects of Rain on Compost

While rain can contribute to wet compost, moderate rainfall can actually benefit the composting process. Rainwater contains natural elements and microorganisms that can enhance the decomposition process. However, excessive or prolonged rainfall can lead to oversaturation and create a soggy compost pile.

Steps to Manage Excess Moisture from Rain

If your compost has been heavily rained on, take steps to manage the excess moisture. Cover your compost pile with a tarp or a cover to prevent further rainwater from entering. If your compost is already too wet, follow the previously mentioned solutions for wet compost to restore the moisture balance.

Should Compost be Allowed to Dry Out?

Pros and Cons of Drying Out Compost

Allowing your compost to dry out can have both benefits and drawbacks. On one hand, drying out the compost can help to restore the moisture balance and promote the activity of beneficial microorganisms. On the other hand, excessive drying can slow down the decomposition process and result in a longer waiting period for mature compost.

Tips for Drying Out Wet Compost

If you choose to dry out your compost, spread it in a thin layer under direct sunlight or in a well-ventilated area. Turn the compost regularly to ensure even drying. Monitor the moisture levels closely to prevent the compost from becoming too dry, as this can create a new set of issues. Aim for a moist, crumbly texture that is ideal for composting.


Maintaining proper moisture levels is crucial for successful composting. Excessive moisture can lead to slow decomposition, nutrient loss, and an increased risk of disease and pests. By recognizing the signs of wet compost and implementing appropriate solutions, you can prevent and manage wet compost issues effectively. Remember to strike a balance between moisture and aeration to create nutrient-rich compost that will benefit your garden. Happy composting!

Question 1:
Answer: Your compost is too wet if it feels like a wet sponge and water drips out when you squeeze it.

Question 2:
Answer: Soggy compost can lead to anaerobic conditions and bad odors, so it’s best to avoid using it.

Question 3:
Answer: It is perfectly fine if compost gets rained on, as rainwater helps to keep it moist and aids in the decomposition process.

Question 4:
Answer: Allowing compost to dry out completely can slow down the decomposition process, so it’s best to maintain a moist but not overly wet consistency.


About the author 

Sam Martinez

Hello, I'm Sam. With a Ph.D. in Environmental Science from Yale, I've dedicated my life to understanding and advocating for our natural world. My work has taken me from the halls of academia to the front lines of environmental activism. I'm thrilled to share stories from my journey, insights from my research, and ways we can all contribute to a healthier planet.