When And How To Harvest Compost

When And How To Harvest Compost: A Comprehensive Guide

Learn everything about when and how to harvest compost. This comprehensive guide covers essential techniques, best practices, and helpful tips for successful compost harvesting.


Composting is a fantastic way to reduce waste, create nutrient-rich soil, and contribute to a more sustainable environment. However, knowing the right time and methods for harvesting compost is crucial to ensure you get the best results. In this article, we will walk you through the process of harvesting compost and provide valuable insights based on firsthand experience and expert knowledge.

When And How To Harvest Compost

How To Harvest Compost


In this section, we will delve into the core aspects of harvesting compost. Let’s explore the best practices, techniques, and key considerations to ensure a successful composting experience.

Understanding the Compost Maturity

One of the key factors in successful compost harvesting is understanding the compost maturity. Compost is created through a process of decomposition, where organic materials break down into a nutrient-rich soil amendment. As compost matures, it undergoes specific changes that indicate it is ready for harvesting.

Identifying Mature Compost

Mature compost exhibits certain characteristics that distinguish it from raw organic matter. When compost reaches its ideal maturity level, it takes on a dark, crumbly texture, resembling rich, fertile soil. The original materials used in the composting process become unrecognizable, and the compost has a pleasant, earthy smell.

Timeframe for Compost Maturity

The timeframe for compost maturity can vary depending on several factors, including the composting method, environmental conditions, and the type of materials used. Generally, it takes about 2 to 6 months for compost to mature fully. However, some composting techniques, such as hot composting, can expedite the process and yield mature compost in as little as a few weeks.

Patience is Key

Composting requires patience, as the decomposition process takes time. While it may be tempting to harvest compost early, it’s essential to allow the microorganisms to complete their work fully. Harvesting premature compost could lead to nutrient deficiencies in the soil and impact plant growth negatively.

Testing Compost Maturity

To ensure your compost has reached the desired maturity, you can perform a simple test. Take a handful of compost from the pile and examine its characteristics. If the compost feels crumbly and loose, with no recognizable pieces of organic matter, it is likely mature and ready for harvesting. On the other hand, if the compost still feels lumpy and contains visible scraps, it needs more time to decompose.

Importance of Mature Compost

Harvesting compost at the right maturity level is vital for its effectiveness as a soil amendment. Mature compost is rich in essential nutrients and beneficial microorganisms, making it an excellent natural fertilizer for your garden. When applied to the soil, it enhances soil structure, improves water retention, and fosters a healthy environment for plant growth.

Monitoring Compost Moisture

Maintaining the right moisture level is crucial for successful composting. Proper moisture ensures that the microorganisms responsible for decomposition can thrive and break down organic materials effectively. Without adequate moisture, the composting process may slow down or stall, leading to an unpleasant, stagnant pile. Here’s how to monitor and manage compost moisture:

The Goldilocks Principle

When it comes to compost moisture, you want it to be just right, like Goldilocks’ famous porridge. Too much water can cause the compost pile to become waterlogged, leading to anaerobic conditions and an unpleasant odor. On the other hand, too little water can hinder microbial activity and slow down decomposition.

Checking Moisture Levels

To monitor compost moisture, follow these steps:

  • Visual Inspection: Take a close look at the compost pile. If it appears dry and crumbly, it likely needs more moisture. Conversely, if it looks excessively wet and spongy, it’s time to reduce the moisture content.
  • The Squeeze Test: Collect a handful of compost from the center of the pile and give it a gentle squeeze. If water drips out, it’s too wet. If the compost doesn’t hold its shape and crumbles apart easily, it’s too dry. The ideal moisture level is when the compost holds its shape but doesn’t release excess water.

Watering the Compost

If the compost is too dry, it’s essential to add water to the pile. Use a watering can or hose with a gentle spray nozzle to moisten the compost evenly. Avoid drenching the pile, as this can lead to over-saturation.

Averting Over-Watering

In case the compost is too wet, take steps to prevent further over-watering. Consider covering the compost pile with a tarp or compost cover to shield it from rain and excess moisture. Additionally, mixing in dry, carbon-rich materials, such as straw or shredded newspaper, can help absorb excess water and balance the moisture levels.

Optimal Moisture Range

For most composting methods, the optimal moisture range is between 40% to 60%. You can use a compost moisture meter to get an accurate reading of the moisture content. Regularly monitoring and maintaining the right moisture level will foster an active and healthy composting process.

Avoiding Compaction

Compacted compost can lead to poor aeration and hinder microbial activity. To prevent compaction, avoid walking or placing heavy objects on top of the compost pile. Instead, use a pitchfork or compost aerator to gently turn and aerate the pile regularly.

Assessing Compost Temperature

Compost temperature is a crucial indicator of the composting process’s activity and progress. As organic materials break down, heat is generated through microbial activity, which accelerates decomposition. Monitoring the compost temperature helps you understand whether the composting process is proceeding as expected and if the compost is approaching maturity.

Importance of Temperature

The temperature of your compost pile provides valuable insights into its overall health and efficiency. When the compost is actively decomposing, the temperature rises significantly. This elevated temperature is essential for several reasons:

  • Pathogen and Weed Control: High temperatures during composting can kill harmful pathogens and weed seeds, ensuring that the final compost is safe for use in your garden.
  • Accelerated Decomposition: Increased temperatures promote the rapid breakdown of organic materials, speeding up the composting process.
  • Nutrient Availability: The heat generated during composting helps break down complex organic compounds into simpler forms, making essential nutrients more readily available to plants.

Measuring Compost Temperature

To assess the temperature of your compost pile, you can use a compost thermometer. Insert the thermometer into the center of the pile at various locations, making sure it’s deep enough to get an accurate reading.

Temperature Ranges

Compost temperatures can vary depending on the stage of decomposition and the composting method used. In general:

  • Mesophilic Stage: At the beginning of composting, the temperature will be in the mesophilic range, typically between 68°F to 113°F (20°C to 45°C). During this phase, bacteria and fungi are the primary decomposers.
  • Thermophilic Stage: As decomposition intensifies, the compost enters the thermophilic stage, where temperatures can soar to 113°F to 160°F (45°C to 71°C). Thermophilic microorganisms, such as thermophilic bacteria, become dominant during this phase.
  • Cooling Stage: Over time, the compost cools down as the decomposition process slows. The temperature will gradually return to ambient levels.

Interpreting Temperature Changes

a. Rapid Temperature Rise: A sudden spike in temperature indicates that the compost is in the thermophilic stage, where decomposition is happening rapidly. This is a positive sign, as it signifies that the compost is actively breaking down organic materials.

b. Gradual Temperature Decrease: As the compost matures and approaches readiness, the temperature will start to decline. This cooling phase indicates that the compost is nearing its final stages of decomposition.

c. Consistently High Temperature: If the compost temperature remains high for an extended period, it suggests that the compost may be too dense or too wet. Consider aerating the compost and adjusting its moisture content to ensure proper decomposition.

d. Temperature Below Ambient: If the compost temperature is consistently lower than the ambient temperature, it may indicate that the compost pile is not active or that the composting process has stalled. In such cases, assess the compost moisture and aeration to revive the decomposition process.

By regularly monitoring the compost temperature, you can gauge the progress of the composting process and make any necessary adjustments to ensure optimal decomposition and the production of high-quality compost for your garden.

Inspecting for Unfinished Material

Inspecting for Unfinished Material
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Before proceeding with compost harvesting, it is essential to conduct a thorough inspection of the compost pile for any unfinished materials. While composting is a natural process that breaks down organic matter, there may still be recognizable pieces of materials that have not fully decomposed.

Importance of Inspecting Unfinished Materials

Identifying and removing unfinished materials from the compost pile before harvesting serves several purposes:

  • Complete Decomposition: Removing unfinished materials ensures that all organic matter has undergone the decomposition process fully. This helps in obtaining a uniform and well-rotted compost.
  • Preventing Contamination: Some materials, such as large food scraps or woody branches, take longer to decompose. Leaving these unfinished materials in the compost can potentially lead to contamination or unpleasant odors in the final compost.
  • Improving Compost Quality: By eliminating unfinished materials, you create a compost product that is rich in nutrients and free from potential hazards or undesirable elements.

Inspecting the Compost Pile

To inspect the compost pile for unfinished materials, follow these steps:

  • Use a Garden Fork: Gently turn and mix the compost pile using a garden fork or compost aerator. This will help expose any unfinished materials that may be buried within the pile.
  • Visual Examination: Look closely at the compost as you turn it. Scan for any recognizable pieces, such as large fruit peels, sticks, or tough plant stems.
  • Check for Tough Materials: Feel for any tough or fibrous materials that might not have fully broken down. These items can include corn cobs, avocado pits, or heavily woody branches.
  • Remove Unfinished Materials: As you identify unfinished materials, remove them from the compost pile and set them aside for further decomposition. Depending on the size and nature of the materials, you can either return them to the compost bin or use them as a green or brown composting ingredient.

Composting Unfinished Materials

If you find unfinished materials during the inspection, don’t worry; they can be composted further. To ensure complete decomposition, consider the following:

  • Chop or Shred Tough Materials: Cutting or shredding tough materials into smaller pieces can accelerate their decomposition. This is especially useful for large fruit peels, stalks, and branches.
  • Create a Separate Pile: If you have a significant amount of unfinished materials, consider creating a separate compost pile dedicated to further decomposition. This pile can be regularly turned and managed to hasten the breakdown process.
  • Balancing Green and Brown Materials: Make sure your compost pile maintains a good balance of green (nitrogen-rich) and brown (carbon-rich) materials. This balanced mix will optimize the composting process and lead to quicker decomposition.

Using the “Push Test”

A simple “push test” can help determine if compost is ready for harvesting. Gently press your hand into the compost pile, and then remove it. If the compost retains the shape of your hand, it is not yet ready. However, if it crumbles, it’s time to harvest.

Harvesting Methods

There are several methods for harvesting compost, each catering to different composting setups and personal preferences. The following are some commonly used methods that allow you to collect mature compost while maintaining an active composting system:

1. Screen and Sift Method:

The screen and sift method is a straightforward approach that involves using a mesh screen to separate finished compost from larger, unfinished materials. Here’s how it works:

  • Place the mesh screen over a wheelbarrow or a container.
  • Shovel the compost onto the screen.
  • Gently shake or sift the compost through the screen.
  • The fine, crumbly compost will fall through the mesh into the container, while any larger, unfinished materials will remain on top of the screen.
  • Collect the finished compost from the container and return the unfinished materials to the compost bin for further decomposition.

2. Side-by-Side Turning:

This method is suitable for compost bins with multiple compartments or those designed for continuous composting. Follow these steps:

  • Identify one section of the compost bin that contains mature compost (usually the one that was filled first).
  • Shift the unfinished compost to the adjacent section of the bin.
  • Allow the mature compost to settle in the emptied section.
  • Continue adding fresh compost materials to the newly emptied section.
  • This method ensures a continuous supply of finished compost while still composting new materials.

3. Tumbling Composters:

Tumbling composters are designed for easy turning and mixing. Follow these steps:

  • Fill the composter with compost materials.
  • Regularly rotate or tumble the composter, either manually or using a rotating mechanism (depending on the type of composter).
  • Turning the composter aerates the compost and speeds up the decomposition process.
  • When the compost inside the composter becomes dark, crumbly, and uniform, it’s ready to be harvested.

4. Direct Harvesting:

For open compost piles or composting in bins without partitions, you can directly harvest mature compost from the bottom of the pile or bin. Here’s how:

  • Carefully remove the upper layer of unfinished materials and set it aside.
  • Harvest the dark, crumbly compost from the bottom of the pile or bin.
  • Return the unfinished materials to the top of the pile or bin for further composting.

5. Pit Composting:

In this method, compost is buried in a pit or trench in the ground. When it’s time to harvest, follow these steps:

  • Dig out the mature compost from the pit or trench.
  • If there are unfinished materials, mix them with the soil in the pit to continue composting.

6. Compost Removal Service:

For larger composting operations or community composting, some regions offer compost removal services. They collect mature compost from your compost bin or pile, and you can use the finished compost in your garden while the service manages the remaining compost.

Choose the method that suits your composting setup and preferences best. Each method has its advantages, so explore and find what works best for your composting needs. Proper harvesting ensures you get the most out of your compost while maintaining a sustainable composting system.

Storing Harvested Compost

Storing harvested compost is crucial to maintain its quality and preserve its valuable nutrients until you are ready to use it in your garden. Proper storage prevents the compost from losing its beneficial properties and ensures it remains in excellent condition for your plants. Here are some essential tips for storing harvested compost:

1. Covered Container or Compost Bin:

Transfer the harvested compost into a covered container or compost bin. A lidded container or bin protects the compost from exposure to the elements, such as rain, wind, and excessive sunlight. This prevents the compost from becoming too dry or too wet, which could compromise its quality.

2. Store in a Cool and Dry Location:

Choose a storage location that is cool and dry. Avoid areas where the compost might be exposed to direct sunlight or high temperatures, as this can cause the compost to break down prematurely and lose its nutrients.

3. Avoid Sealed Plastic Bags:

While it may be tempting to store compost in sealed plastic bags for convenience, it’s best to avoid this practice. Compost needs to breathe and should not be completely sealed in plastic, as it can create anaerobic conditions that lead to unpleasant odors and slow down decomposition.

4. Use Breathable Bags or Fabric Sacks:

If you prefer to store compost in bags, opt for breathable fabric sacks or burlap bags. These allow air circulation while still protecting the compost from excessive moisture and debris.

5. Keep the Compost Slightly Damp:

Maintaining a slightly damp environment is beneficial for stored compost. The moisture helps preserve the compost’s nutrient content and prevents it from drying out. However, be cautious not to make the compost too wet, as excessive moisture can lead to mold growth and unpleasant odors.

6. Regularly Check the Compost:

Periodically check the stored compost for moisture content and any signs of mold or pests. If the compost appears overly dry, lightly mist it with water. If you notice any issues, address them promptly to ensure the compost remains in optimal condition.

7. Use within a Reasonable Timeframe:

While compost can be stored for an extended period, it’s best to use it within a reasonable timeframe to maximize its benefits. Try to use the compost within six months to a year of harvesting, as fresher compost tends to be more nutrient-rich.

8. Rotate Stored Compost:

If you have multiple containers of stored compost, consider rotating them. Use the older compost first, allowing newer batches to age further before use. This helps maintain a continuous supply of high-quality compost for your garden.

By following these storage guidelines, you can preserve the integrity of your harvested compost and ensure that it remains a valuable resource for enriching your soil and nourishing your plants. Properly stored compost contributes to healthier and more robust plant growth, making your gardening efforts even more rewarding.

How To Use Your Harvested Compost

How To Use Your Harvested Compost
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Using your harvested compost is an exciting and rewarding process that will benefit your garden in numerous ways. Compost is a valuable soil amendment that improves soil structure, enhances nutrient content, and fosters healthy plant growth. Here are some effective ways to use your harvested compost in your garden:

1. Top Dressing:

One of the simplest ways to use compost is by applying it as a top dressing. Sprinkle a layer of compost on the soil surface around your established plants, shrubs, and trees. Gently work the compost into the top layer of soil with a rake or a hoe. The compost will slowly release nutrients and improve soil health over time.

2. Soil Amendment:

Mix compost into your garden soil to enhance its overall fertility and structure. Blend the compost thoroughly with the existing soil, aiming for a ratio of about 20% to 30% compost to 70% to 80% soil. This amended soil will be teeming with beneficial microorganisms, providing a nourishing environment for your plants.

3. Potting Mix Enrichment:

Revitalize your potting mix by adding compost to it. Incorporate compost into the potting mix to improve its water retention capacity and nutrient content. This will help your container plants thrive and reduce the need for frequent fertilization.

4. Seed Starting Mix:

Create a nutrient-rich seed starting mix by combining compost with a sterile seed starting medium. This mixture provides essential nutrients to young seedlings as they germinate and grow.

5. Compost Tea:

Make compost tea by steeping compost in water for a few days. Use this liquid to water your plants or as a foliar spray. Compost tea is a fantastic way to deliver a concentrated dose of nutrients directly to the roots or leaves of your plants.

6. Mulching:

Spread a layer of compost around the base of your plants as mulch. Compost mulch helps retain soil moisture, suppresses weed growth, and gradually releases nutrients into the soil as it decomposes.

7. Compost Pockets:

When planting new seedlings or transplants, create compost pockets by digging holes and filling them with compost. Place the plants directly into these nutrient-rich pockets to give them a healthy start.

8. Lawn Treatment:

Apply a thin layer of compost to your lawn, especially in areas with poor soil. This will enrich the soil and promote a healthier, greener lawn.

9. Compost for Trees and Shrubs:

Mature trees and shrubs can benefit from the application of compost around their base. Spread compost in a circle around the tree or shrub, avoiding direct contact with the trunk. This improves soil quality and supports the long-term health of these plants.

10. Compost for Container Gardening:

Regularly incorporate compost into the soil of your container plants. The compost will provide essential nutrients to the confined roots and contribute to healthier and more vigorous growth.

Using your harvested compost effectively throughout your garden will enhance soil fertility, improve plant health, and promote a sustainable and thriving ecosystem. Compost is a powerful resource that nourishes the soil and fosters a bountiful harvest of vibrant and healthy plants.

How Long Does Compost Take?

How Long Does Compost Take?

The time it takes for compost to fully mature and be ready for use can vary depending on several factors, such as the composting method, the types of materials used, and environmental conditions. In general, composting is a gradual process that requires patience and attention to achieve the best results. Here’s a general timeline for how long compost takes to mature:

1. Initial Decomposition (2 to 4 Weeks):

During the first few weeks of composting, microorganisms such as bacteria and fungi begin breaking down the readily available materials. The compost pile will start to heat up as these microorganisms work actively, and the materials will begin to decompose.

2. Active Decomposition (1 to 6 Months):

As the composting process continues, it enters the active decomposition phase. The internal temperature of the compost pile will rise significantly, reaching the thermophilic stage, where temperatures can range from 113°F to 160°F (45°C to 71°C). This stage accelerates the breakdown of organic materials, especially if the compost pile is regularly turned or aerated.

3. Maturation (2 to 6 Months or Longer):

After the active decomposition phase, the compost enters the maturation stage. During this period, the compost temperature starts to decrease, and the compost begins to stabilize. The compost pile will cool down and may take on a darker, crumbly texture with an earthy smell. This is an indication that the compost is becoming mature.

4. Readiness for Harvesting (2 to 6 Months or More):

The exact time it takes for compost to mature and be ready for harvesting varies. On average, compost can be considered ready for use after 2 to 6 months, depending on factors such as the composting method, the types of materials used, and the level of care and attention given to the compost pile. In some cases, it may take even longer for the compost to fully mature.

Factors Affecting Composting Time:

Several factors can influence the composting time:

  • Composting Method: Hot composting methods, such as regular turning or using compost tumblers, can speed up the composting process compared to passive or cold composting methods.
  • Materials Used: The types of materials used in the compost pile can affect composting time. Nitrogen-rich “green” materials (e.g., kitchen scraps, grass clippings) decompose faster than carbon-rich “brown” materials (e.g., leaves, straw). A good balance of green and brown materials accelerates decomposition.
  • Moisture and Aeration: Proper moisture levels and regular aeration promote microbial activity, leading to faster composting.
  • Compost Size: Smaller compost piles or compost bins may decompose more quickly than larger ones.
  • Environmental Conditions: Compost piles in warmer climates or during the summer months may compost faster than those in colder regions or during winter.

What Does Finished Compost Look Like?

Finished compost has distinct characteristics that differentiate it from the raw organic materials used in the composting process. When compost reaches its ideal maturity, it transforms into a valuable, nutrient-rich soil amendment with unique visual and sensory qualities. Here’s what finished compost looks like:

1. Dark and Crumbly Texture:

One of the most apparent signs of finished compost is its dark color and crumbly texture. As organic materials decompose, they break down into smaller particles, resulting in a uniform, fine texture resembling rich, dark soil.

2. Earthy Smell:

Finished compost emits a pleasant, earthy smell, similar to the smell of fresh soil. This is a result of the breakdown of organic matter by beneficial microorganisms, which release compounds that contribute to the compost’s characteristic aroma.

3. Absence of Recognizable Materials:

In finished compost, the original materials used in the composting process are no longer recognizable. Any food scraps, plant residues, or other organic matter will have fully broken down, leaving behind a homogeneous mixture of decomposed material.

4. No Sign of Fresh Organic Matter:

You should not find any fresh or partially decomposed organic matter in finished compost. The composting process should have completed, leaving behind a stable, nutrient-rich product ready for use.

5. Cool to the Touch:

Compost that has reached maturity will feel cool to the touch, especially when compared to a compost pile that is actively decomposing and generating heat. The temperature of finished compost will be closer to ambient temperature.

6. Uniform Appearance:

Finished compost is uniform in appearance, with a consistent texture and color throughout the entire batch. There should be no pockets of uncomposted material or areas with a significantly different texture.

7. Moist but Not Soggy:

Finished compost should have a slightly damp feel, but it should not be soggy or wet. The compost’s moisture content should be sufficient to hold its crumbly texture without dripping excess water.

8. Free of Unpleasant Odors:

Healthy, finished compost should not emit any foul or unpleasant odors. The decomposition process should have effectively broken down organic matter, eliminating any potential odors associated with raw materials.

9. Ready for Use in the Garden:

The ultimate indicator of finished compost is its readiness for use in the garden. Once compost has achieved the described characteristics, it is a valuable soil amendment that can be incorporated into the garden to improve soil structure, enhance nutrient content, and promote healthier plant growth.

By recognizing the visual and sensory attributes of finished compost, you can confidently apply this nutrient-rich resource to your garden, knowing that it will significantly contribute to the success of your plants and the overall health of your soil.

Frequently Asked Questions (FAQs)

Here are some commonly asked questions about compost harvesting, along with concise answers:

When is the best time to harvest compost?

The best time to harvest compost is when it reaches a dark, crumbly texture, and the original materials are no longer recognizable. It typically takes 2 to 6 months for compost to mature.

Can I harvest compost in the winter?

Yes, you can harvest compost in the winter, but the decomposition process may be slower due to colder temperatures. It’s advisable to cover the compost pile to retain heat and moisture during winter.

How often should I harvest compost?

The frequency of compost harvesting depends on your composting method and the size of your compost bin. For traditional compost piles, harvesting every 2 to 6 months is common.

Can I use unfinished compost?

While unfinished compost may contain some recognizable organic materials, it’s still beneficial to use in your garden. You can return unfinished materials to the compost bin to complete the decomposition process.

What should I do with excess compost?

If you have more compost than your garden can utilize, consider sharing it with friends, neighbors, or local gardening communities. Compost is a valuable resource for all gardeners.

Is composting a sustainable practice?

Absolutely! Composting is an eco-friendly and sustainable practice that reduces waste, enriches soil, and minimizes the need for chemical fertilizers.


Composting is a rewarding and environmentally friendly way to manage organic waste and improve soil quality. Knowing when and how to harvest compost is essential for maximizing its benefits. Remember to assess its maturity, moisture, and temperature, and use the appropriate harvesting method. By utilizing your compost wisely, you’ll enjoy healthier plants, better soil, and contribute to a greener planet.