As gardeners, we are always looking for ways to keep our growing as natural as possible, and part of that is finding ways to improve the soil without using chemical fertilizers. Wood is about as natural a product as you can get, so gardeners with access to wood, wood chips, and sawdust may see this as a benefit for improving their soil cheaply and naturally.
Wood chips can build and develop soil, but there are some essential facets for doing it right.
Wood chips can be used as a medium to develop and build your soil through composting the wood chips, mulch, or tilling directly into the soil. Using wood chips can have some drawbacks, but these drawbacks can be managed for the successful use of this resource.
Most gardeners know that wood decomposes and produces excellent compost and nutrient-rich organic matter that helps to enrich the soil and improve soil quality. Most gardeners don’t know that simply adding wood chips to your garden can have a detrimental effect before it starts to benefit the soil.
Can You Use Wood Chips To Build And Develop Soil?
Wood chips are a natural product that many gardeners can access relatively cheaply and sometimes for free. This ease of access to organic material may tempt gardeners to use this medium liberally in their garden to improve and develop their soil.
Other gardeners have heard stories that wood in all its forms, be it pieces of wood, wood chips, or sawdust, can damage the soil and hinder your soil development and plant growth. These rumors discourage these gardeners from using wood chips and other forms of wood to enrich the soil.
The reality is that wood chips and other wood forms can be used to build and develop your garden soil to produce a rich growing medium. However, getting to this point is not as simple as tilling wood chips into the soil.
What Are The Dangers Of Using Wood Chips To Develop Soil?
There are several aspects to using wood chips in your garden that you need to be aware of to use the wood chips correctly and use the right kind of wood.
There are three main causes of concern about using wood chips to build your soil.
- Nitrogen depletion.
- The right type of wood
- Toxins in the wood.
Nitrogen Depletion By Wood Chips
As the wood decomposes in the soil, it absorbs nitrogen from the surrounding soil during the decomposition process. This does not mean that the nitrogen is lost to the soil, but it is temporarily locked up in the wood as it decomposes.
This means that fresh wood in the soil will cause a temporary lack of nitrogen, which can hinder plant growth unless nitrogen is added to the soil to compensate for the low levels.
Once the wood has decomposed, the nitrogen will be released back into the soil and will be readily available for use by your plants, along with the other nutrients released by the decomposed wood chips.
The effect that temporary nitrogen depletion will have on your soil will depend on how you use the wood chips and apply them to your soil.
Use The Right Wood Chips
The type of wood that the wood chips are made from has a bearing on their suitability in building and developing your garden soil.
Hardwoods take a long time to decompose and add any benefit to the soil. Wood chips from softwood, in contrast, break down much faster and will release their nutrients into the soil quicker. If you can get your hands on wood chips made from softwood trees, it would be preferable to wood chips from hardwood trees.
If the wood chips are from a mixture of hard and softwood trees, this provides an ideal mix and acts as a long-term slow release of nutrients and soil improvement. The softwood will decompose first, and the hardwood will take longer, providing a slow, constant release of nutrients into the soil.
There are some thoughts that certain woods such as black walnut, maple, and eucalyptus wood, among others, release chemicals into the soil that will hinder seed germination and kill young seedlings.
While it is true that these woods release growth inhibiting chemicals, these chemicals only affect a certain type of plants and are unlikely to pose a problem in your garden, particularly if you use the wood chips correctly.
Toxins From Wood Chips
An aspect of wood chips that is more likely to be an issue than the wood releasing growth-inhibiting chemicals is manmade chemicals in the wood.
It is essential to know where the wood chips came from and what wood was used to make the chips. Wood used in pallet construction or any type of shipping packaging should be treated with suspicion. Many of these woods are treated with toxic chemicals to prevent harmful insects from being transported to regions where they don’t belong and improve the wood’s longevity.
Wood used as decking is often treated with preservatives should also not be chipped and used on the garden. Likewise, wood treated with chemicals such as creosote on fenceposts should not be used as wood chips in your garden.
Plywood and other forms of laminate board use adhesive to hold the layers of wood together. If this wood is chipped, the glue is included in the chips you incorporate into your soil.
These reasons make it important to know what wood the wood chips are made from before deciding to use them in your soil. Any chemicals used to treat the wood will end up in your soil and may be detrimental to the plants’ health and growth and is of particular importance if you consume the plants.
Do Wood Chips Make Good Soil?
Now that we have discussed all these negative aspects of using wood chips to build and develop soil, you may be concerned whether wood chips will improve the soil at all!
Wood chips make good soil and improve the quality of the soil and the nutrient levels in the soil, provided the wood chips are used in the right way.
You can employ several methods to use wood chips in your garden to build and develop the soil without adversely affecting your plants that are already growing and affecting seed germination and seedling growth.
How To Build And Develop Soil With Wood Chips?
Soil can be improved by using wood chips, but whichever way you use the wood chips will take some time to benefit the soil. Wood chips are chunky and dense and will take longer to decompose and release nutrients into the soil than many other types of organic matter.
There are 3 main ways to effectively use wood chips to build and develop your soil, and each comes with its own methods and length of time before you will see results.
Composting Wood Chips
Wood chips can be composted like any other organic matter. Composting is a relatively quick and effective way of using woodchips than any of the other methods.
Wood chips can be composted in one of two ways. You can pile the wood chips up in the corner of your garden and wait about a year, or you can create an active compost pile with a mixture of green and brown organic material to speed up the composting process.
Wood chips piled up in your garden will eventually decompose into compost, but it will take a long time. This is the simplest way to compost wood chips since you only have to moisten the pile periodically with water and turn it every couple of months.
The faster way to compost wood chips and get them contributing to building and developing your soil is to create an active compost pile.
To create an active compost pile, you will need a mixture of green and brown organic material. Green material is plant material that still has a moisture content, such as fresh lawn clippings, organic kitchen waste, green leaves, and similar materials. The brown material consists of dead, dry organic material such as dry twigs and branches, wood chips, fall leaves, and similar dry materials.
These materials are layered alternately to produce a pile of the organic matter about 3 to 5-feet high. Add water to the pile to increase the moisture content. If you live in a warm climate, the compost pile can be left open, but in cooler climates, you can cover with compost with canvas or black plastic sheeting to keep the heat in the pile. To increase the nutrient level of the compost and increase the nitrogen available to compost the wood chips, you can sprinkle a couple of handfuls of NPK fertilizer into the compost layers.
The added heat and moisture will accelerate the composting process and break all the organic materials down faster, including the wood chips. You should leave the compost pile for a week to two weeks and then turn it every 7 to 10-days, covering it up again each time after turning.
This process will provide you with a rich organic material within 3 to 4-months that will increase the nutrient content of your soil and the organic matter content. The additional organic matter will enhance the water retention and drainage characteristics of the soil.
Mulching With Wood Chips
Mulching with wood chips is another method of building your soil with wood chips, but there is a method to doing it correctly.
Mulching with wood chips offers the following benefits.
- Slow-release of nutrients from above. As the wood chips on the ground’s surface start to decompose, they release nutrients at the top of the soil. This will make more nutrients available to plants with shallow root systems.
- Weed suppression. Wood chips used as a mulch suppress the growth of weeds in between the plants you are cultivating. This prevents weeds from taking up nutrients that could otherwise be used by your plants and also reduces the work involved for the gardener in pulling out weeds.
- Soil moisture retention. Wood chip mulch helps reduce the evaporation of moisture from the soil’s surface. This promotes the growth of micro-organisms and worms in the soil’s upper layers, which assist plant growth.
- Soil temperature control. Wood chip mulch helps keep the surface temperature of the soil cooler and reduces temperature fluctuations. The constant temperature combined with better moisture retention translates to a healthier, richer, more nutritious soil.
The main problem with using wood chips as mulch is that it takes a long time to break down and enrich the soil. However, during this time, you benefit from the wood chips in the role of mulch.
Some people are concerned with the wood chips tying up the nitrogen in the upper levels of the soil when they are used as mulch. This problem can be mitigated by placing a layer of compost on the soil’s surface before laying down the wood chip mulch.
The compost will act as a barrier between the mulch and the soil’s surface, and the wood chips will gain nitrogen from the compost rather than the upper layers of soil.
As the lower layers of the wood chip mulch break down, they will release the nitrogen and other nutrients, which will filter down into the soil, further developing the quality of the soil.
Tilling Wood Chips Into Soil
Tilling or digging wood chips directly into the soil is not a method that is recommended by most gardeners. However, this method can be used to build and develop your soil.
The main argument against using this method is the nitrogen the wood chips absorb from the soil and tie up during their decomposition can adversely affect plant growth.
There are ways to get around this problem and still gain the benefits that wood chips bring to your soil. If you are letting a portion of your ground lie fallow to build up the soil, you can certainly dig wood chips into the ground as part of your soil development program.
Dig the wood chips thoroughly into the topsoil and sprinkle some NPK fertilizer or some blood and bone fertilizer into the mix as you are digging it in. Leaving the piece of ground to lie fallow for 6-months to a year will give the wood chips time to begin breaking down and composting in the soil and improving drainage and water retention.
You can also dig wood chips into beds with existing plants, but you would need to add additional nitrogen to compensate for the nitrogen that the wood chips will absorb from the surrounding soil. Wood chips dug into the soil this way will cause a slight increase in the soil’s acidity, so ensure you only use this method with plants that prefer acidic soils.
You could adjust the pH of the soil to bring it back to within 6.0pH and 7pH by adding some lime to the soil as you dig in the wood chips. If you dig wood chips into an existing bed with plants, it would be best to only do so in the gaps between plants to avoid digging up any of the plant’s root systems and causing damage.
Wood chips can be a great, cost-effective way to build and develop your soil to the point that they can support healthy and productive plant growth.
Using wood chips as an ingredient to improve your soil can be done, but it should be done in conjunction with other methods such as composting to speed up the process of the wood chip decay.
Our first choice as the best way to include wood chips in your soil development is to compost the wood chips with other organic material.
The second-best alternative is to compost your beds and use wood chips as an organic mulch to give a slow release of nutrients and humus into the top layer of the soil.
The wood chip option that is least likely to produce fast results in the development of your soil is tilling the wood chips into the soil. This is the slowest and riskiest of the options and should only be done if your soil will be lying fallow for a season.