Wood Chip Composting: A Comprehensive Guide to 5 Methods and 4 Uses

Updated at: 22/05/2025

This comprehensive guide explores the versatile world of wood chip composting, detailing five distinct methods for transforming this readily available resource into valuable garden amendment. From the controlled environment of the Johnson Sioux bioreactor to the simpler approach of open-air heaps, we examine the principles behind effective decomposition, highlighting the crucial roles of moisture, aeration, and the addition of nitrogen-rich green materials. We'll compare the decomposition rates of different wood chip sizes and explore how various techniques influence the resulting compost's quality and microbial composition.Beyond composting, we also uncover the multifaceted applications of wood chips in gardening, demonstrating their uses as aesthetically pleasing pathways and soil-enriching amendments. Learn how to optimize the decomposition process to maximize the benefits for your plants and discover the best method to suit your specific needs and resources. Whether you're a seasoned gardener or a curious beginner, this guide provides practical advice and insights into harnessing the potential of wood chips for a thriving garden.

Pros And Cons

Woodchip
  • Relatively new, widely available resource
  • Guaranteed free of chemical pollution
  • Adds fertility to soil
  • Long-lasting fertility effects
  • Can be used in pathways
  • Can be added to compost heaps
  • Can be used to fill beds
  • Can be used to make biochar
  • Needs to be moist to decompose properly
  • Dryness prevents decomposition
  • Large pieces of wood take a long time to break down
  • Can suck nitrogen out of the rooting zone if dug into the ground
  • May lead to slug population if large pieces of wood and bark are present
  • Early growth may be weak and yellow if used in large quantities in beds

Read more: 10 Best Electric Smoker Wood Chips for Delicious BBQ

Johnson Sioux Bioreactor: A Year-Long Decomposition Process

The Johnson Sioux bioreactor, a unique composting method, involves creating a contained heap of wood chips. This method is designed to optimize decomposition by managing moisture and aeration. The process takes approximately a year, during which various stages of fungal and bacterial activity occur.

View of the dry edges and moist interior of the bioreactor after one year.
View of the dry edges and moist interior of the bioreactor after one year.

A key observation is the importance of moisture for effective decomposition. The outer edges of the heap tend to dry out, emphasizing the need for consistent watering throughout the year. Monitoring the internal temperature can indicate the level of decomposition activity.

Adam showing the decomposed woodchip from the center of the bioreactor.
Adam showing the decomposed woodchip from the center of the bioreactor.

The decomposed material from the bioreactor displays rich, dark color and fine texture. This finished compost is ideal for enriching soil, providing long-lasting fertility benefits.

Comparing Fresh and Aged Wood Chip Heaps

A comparison of two wood chip heaps – one two weeks old and the other five months old – highlights the decomposition process. The newer heap shows a higher internal temperature, indicative of active decomposition. This temperature is influenced by the moisture content.

Side-by-side comparison of a fresh and an older wood chip heap.
Side-by-side comparison of a fresh and an older wood chip heap.

The older heap, though drier, reveals signs of decomposition with dark color and some visible breakdown. The presence of green material in the heap is beneficial, accelerating decomposition.

Thermometer inserted into the newer wood chip heap, showing the internal temperature.
Thermometer inserted into the newer wood chip heap, showing the internal temperature.

The size of wood pieces plays a significant role in decomposition rate. Smaller pieces break down faster, offering quicker fertility benefits for plants. Larger pieces are slower to decompose but are harmless on the soil surface.

Close up of a wood chip heap that includes green material.
Close up of a wood chip heap that includes green material.

Aerated Composting with Pallets

This method utilizes pallets to create air passages within the wood chip heap, promoting aerobic decomposition. Holes are drilled into the pallets to allow air circulation. This ensures that the compost remains oxygenated throughout the process.

A wood chip compost heap built with a pallet base and air pipes.
A wood chip compost heap built with a pallet base and air pipes.

The addition of green material, such as weeds or grass clippings, accelerates decomposition by providing nitrogen. Similarly, incorporating chicken manure adds additional nitrogen, balancing the carbon-rich wood chips.

Thermometer measuring the internal temperature of the aerated compost heap.
Thermometer measuring the internal temperature of the aerated compost heap.

This method aims to avoid the need for turning the compost heap, offering a low-maintenance approach to wood chip composting. Monitoring the internal temperature helps to assess the decomposition progress.

Using Wood Chips in the Garden: Four Creative Applications

Wood chips have versatile applications in gardening beyond composting. One use is as pathways, offering a natural and aesthetically pleasing surface. It's essential to ensure the wood chips are small enough to prevent slug infestation.

Using a lawnmower to shred wood chips into smaller pieces.
Using a lawnmower to shred wood chips into smaller pieces.

Adding sieved wood chips to compost heaps is another method. The smaller pieces facilitate rapid decomposition. The resulting compost enhances soil fertility.

A garden path made from decomposed wood chips.
A garden path made from decomposed wood chips.

Filling garden beds with wood chips can also enhance soil structure and improve drainage. However, using larger pieces can lead to a temporary nutrient depletion. Smaller pieces or sieved wood chips minimize this effect.

Garden bed experiment comparing growth with wood chips and compost.
Garden bed experiment comparing growth with wood chips and compost.

Microscopic Examination and Conclusion

Microscopic examination of the wood chip samples reveals the diverse fungal and bacterial life involved in decomposition. Different decomposition methods, like the Johnson Sioux bioreactor and open-air heaps, result in different microbial communities and compost characteristics.

Microscope image of the wood chip compost.
Microscope image of the wood chip compost.

The choice of composting method depends on factors such as available resources, time constraints, and desired outcome. The Johnson Sioux bioreactor requires more initial setup, while open-air heaps are simpler but may require more attention to moisture.

Overall, wood chips are a valuable, sustainable resource for gardening, offering multiple uses for improving soil, pathways, and compost. Experimentation with different methods can reveal the best approach for individual needs.