Are Spruce Wood Chips Good for Gardens? 7 Reasons to Mulch Using Spruce Chips

Gardening experts are constantly searching for ways to enhance their plant’s growth, maintain a sustainable ecosystem within their gardens, and improve soil quality. One of the ways to do this is by using wood chips. Moreover, wood chips have long been recognized as a cost-effective and eco-friendly mulching material, but what wood mulch should you use? Are spruce wood chips good for gardens? One of the readers asked.

Yes, spruce wood chips are beneficial for gardens, the chips have desirable decomposition rates, which contributes to their long-lasting effects of nutrients provision in garden beds. The chips have fine texture, pleasant aroma, and rich brown color.

As the chips decomposes, they gradually release essential nutrients, such as nitrogen, phosphorus, and potassium, into the soil. This natural fertilization process promotes robust plant growth and vitality, reducing the need for synthetic fertilizers.

Furthermore, the decomposition of spruce wood chips enhances soil structure by improving its moisture-holding capacity and promoting beneficial microbial activity.

However, spruce wood chips may not be universally suitable for all gardening scenarios. For instance, factors such as specific plant species, local climate conditions, and garden aesthetics should be considered when determining the optimal use of wood chips.

In this post, I’ll discuss more regarding spruce wood chips for gardens. So, keep reading for more insight into the subject.

What Are The Pros And Cons Of Spruce Wood Mulch?

  • Aesthetic Appeal

Spruce wood has a natural, earthy appearance that can enhance the visual appeal of your garden or landscape. Furthermore, it provides a neat and finished look to flower beds, pathways, and other areas.

  • Moisture Retention

Mulch helps to retain soil moisture by reducing evaporation. Also, it acts as a protective layer, shielding the soil from direct sun exposure and wind. Even better, spruce wood mulch can help keep the soil moist, which is particularly beneficial during hot and dry periods.

  • Organic Matter And Soil Improvement 

Over time, spruce wood decomposes and adds organic matter to the soil. This improves soil structure, enhances nutrient availability, and promotes beneficial microbial activity.

  • Weed Suppression 

Mulch acts as a barrier preventing sunlight from reaching weed seeds and suppressing their growth. Furthermore, spruce wood mulch can reduce the number of weeds in your garden, making maintenance tasks better.

  • Temperature Moderation

Mulch acts as insulation for the soil, providing a buffer against extreme temperature fluctuations. Moreover, spruce wood mulch can help keep the soil cooler in hot weather and protect plant roots from freezing during winter.

  • Erosion Control

Spruce wood mulch helps prevent soil erosion by reducing the impact of rainwater and wind on the soil surface. Additionally, it acts as a protective layer that slows down water runoff and holds the soil in place, preventing erosion as well as the loss of valuable topsoil.

  • Sustainable And Renewable 

Spruce wood mulch is made from a renewable resource (sprue trees). Even better, when sourced responsibly, it can be an environmental choice for mulching, as it utilizes a byproduct of the forestry industry and reduces waste.

Cons of Spruce Wood Mulching

  • Natural Depletion

Spruce wood mulch, like other wood-based mulches, can temporarily deplete nitrogen from the soil during the decomposition process. Further, the microbes that break down the mulch utilize nitrogen from the soil, which can temporarily create a nutrient balance.

In addition, this can affect nitrogen-sensitive plants unless additional nitrogen is provided through fertilization.

  • Availability And Cost

Depending on your location, spruce wood mulch may not be readily available or maybe more expensive compared to other types of mulch. Additionally, availability and cost can vary based on regional factors as well as local suppliers.

  • Termite Attraction

Wood mulches, including spruce wood mulch, can attract termites, especially if the mulch is in close proximity to wooden structures or foundations. Additionally, in areas prone to termite infestations, using wood mulch near buildings may increase the risk of termite damage.

  • Potential For Mold And Fungus

Wood based mulches, including spruce wood mulch, can create a favorable environment for the growth of mold and fungus, particularly in wet or consistently moist conditions…

Furthermore, this can lead to the development of plant diseases and aesthetic issues in the garden.

  • Acidification Of Soil

Spruce wood mulch tends to have slightly acidic ph. Over time, as the mulch decomposes, it can gradually lower the soil’s ph.

While this may be beneficial for acid-loving plants, it may not be suitable for plants that prefer neutral or alkaline soil conditions. Regular monitoring of soil pH is recommended if spruce wood mulch is used extensively.

  • Mulch Depth And Maintenance

Spruce wood mulch, like any mulch, requires proper maintenance. It should be applied at any appropriate depth (like 2-4 inches) and replenished as needed to maintain its effectiveness. Mulch can also become compacted, hindering water and air movement, so occasional raking or loosening may be necessary.

Spruce Vs Cedar Vs Pine Chips for Gardens

There are various factors to consider when it comes to using spruce, cedar, or pine chips for gardens. Here is a comparison of the three:

Availability And Cost 
  • Cedar Chips 

Cedar chips are popular for their aromatic fragrance and insect-repellent properties. They are commonly used as mulch for gardens, flower beds, and pathways.

Additionally, cedar chips tend to be more expensive compared to spruce and pine chips due to their desirable properties as well as limited availability in certain regions. Its availability can vary depending on the proximity to cedar mills or forests.

  • Spruce Chips

Spruce chips are lightweight and offer good moisture retention properties. Further, spruce chips are generally readily available in many regions, particularly in areas where spruce trees are abundant. In addition, the cost of spruce is moderate, falling somewhere between cedar and pine chips.

  • Pine Chips

They are widely available and relatively inexpensive compared to cedar chips. Also, they are commonly from various pine tree species. Moreover, they can be found in many regions where pine trees are grown or harvested for commercial purposes.

However, it is important to note that the availability and cost of these wood chips can vary depending on factors such as local supply, demand, transportation costs, and seasonal variations. They can also vary based on the supplier and retailers.


Spruce chips have a light color, ranging from pale yellow to a light golden shade. Moreover, they have a uniform appearance with a fine texture. Also, the chips tend to be smaller in size and have a consistent shape.

On the other hand, depending on the pine species, pine chips come in different colors. They can range from light brown to reddish-brown or even darker shades. Also, pine chips often have a coarser texture compared to spruce chips, and may contain more visible wood fibers.

Additionally, the size of pine chips can vary, with some larger pieces mixed in. Conversely, cedar chips have a distinctive reddish-brown color, which is a characteristic feature of cedar wood. They have a coarser texture compared to spruce and pine chips, with individual pieces thicker.

Cedar chips often have a natural aromatic scent that is released when they are used.

Acidic Properties

Pine chips have a higher acidity level compared to spruce and cedar chips. Therefore, if you have plants that prefer acidic soil, such as azaleas or blueberries, pine chips can be beneficial. However, for plants that require neutral or alkaline soil, spruce or cedar chips would be a better choice.


Cedar chips are known for their durability and resistance to decay as well as insect infestation. They contain natural oils that act as a deterrent to pests and help preserve the wood. Contrarily, spruce chips are less durable than cedar but still have some resistance to decay.

Pine chips on the other hand are the least durable and can break down relatively.

Moisture Retention 

Cedar chips have good moisture retention properties, helping to conserve water in the soil and reduce evaporation. On the other hand, spruce, and pine chips also provide some moisture retention but to a lesser extent.

Decomposition Rate 

Spruce, pine, and cedar are all considered to have a relatively slow decomposition rate. However, the exact rate can vary depending on various factors like moisture, temperature, and microbial activity in the environment.

Furthermore, spruce, pine, and cedar chips have different chemical compositions, which can affect their decomposition. Pine and cedar contain natural compounds, such as oils and resins, which can slow down the decomposition process due to their resistance to microbial breakdown.

As a result, spruce chips may decompose somewhat faster than pine and cedar due to lower resin content.

What Is the Best Wood Chip to Use In a Garden?

The choice of wood chips for a garden depends on various factors, including your specific gardening needs and preferences. They include:

  • Hardwood Chips

Hardwood chips, such as those obtained from trees like oak, Beech, or maple, are a popular choice for garden mulch. They decompose relatively slowly, provide good weed suppression, retain moisture in the soil, and add organic matter as they break down.

Moreover, hardwood chips can enhance soil structure and improve nutrient availability.

  • Pine Chips

Pine chips, from pine trees, have a pleasant aroma and are widely available. They decompose more quickly than hardwood chips but are still beneficial for weed control and moisture retention. Further, pine chips can slightly acidify the soil, making them suitable for acid-loving plants like azaleas and blueberries.

  • Cedar Chips

Cedar chips are known for their durability and resistance to decay. They can last longer compared to other wood chips, making them suitable for pathways or areas where mulch replacement is less frequent. Cedar chips have a natural insect-repellent property due to their aromatic oils.

  • Cypress Chips 

Cypress chips are another option for garden mulch. They are long-lasting, resist decay, and have natural pest-repellent properties. However, it’s essential to consider the sustainability of cypress wood and ensure it comes from responsibly managed sources.

  • Fruit Chips 

Wood chips derived from fruit trees, such as apples or cherries, can be an excellent choice for gardens. They provide organic matter, suppress weeds, and contribute to soil fertility. Additionally, fruit tree chips can release pleasant aromas as they decompose.

How Thick Should Spruce Chips Be For Garden

When using spruce chips or any other types of wood chips as mulch in your garden, the ideal thickness depends on a few factors. Here are some general guidelines to consider:

  • Organic Matter Breakdown 

Over time, wood chips break down and contribute organic matter to the soil. Further, if you want a slower decomposition rate, which is beneficial for perennial plants, a thicker layer of 3- to 4 inches (7 to 10 centimeters) is sufficient.

For annual plants or vegetable gardens, a thinner layer of 2 to 3 inches (5 to 7 centimeters) may be more appropriate as it allows faster nutrient release.

  • Moisture Retention

The primary purpose of mulch is to help retain moisture in the soil by reducing evaporation. To achieve this, a layer of wood chips about 2-4 inches (5 to 10 centimeters) thick is recommended. This thickness provides adequate coverage to slow down moisture loss while allowing air and water penetration.

  • Weed Suppression

Mulch also helps suppress the growth of weeds by blocking sunlight and preventing weed seeds from germinating. A thicker layer of wood chips around 4 to 6 inches (10 to 15 centimeters), can provide better weed control.

However, avoid piling mulch too close to the base of plants to prevent moisture buildup and potential rot.

How Long Will It Take Spruce Chips to Decompose? 

Like other types of wood chips, spruce chips can take some time to decompose. The rate of decomposition can be influenced by various factors such as:

Chip Size: The size of the spruce chips can affect the decomposition rate. Smaller chips or shredded mulch will decompose faster than larger chips because they have a greater surface area, allowing microorganisms to break them down more efficiently.

Moisture and Temperature: Adequate moisture and warmer temperatures can accelerate the decomposition process. Moreover, moisture helps create a favorable environment for microbial activity, while warmer temperatures increase the metabolic rate of microorganisms, leading to faster decomposition.

However, excessive moisture can also promote fungal growth, so it’s important to maintain a balance.

Microbial Activity: Microorganisms including bacteria and fungi play a crucial role in breaking down organic matter. The presence of a diverse and active microbial community in the soil will enhance decomposition. Adding compost or well-rotted organic matter to the soil can introduce beneficial microorganisms and accelerate decomposition.

Soil Conditions: The composition and health of the soil can impact decomposition rates. Well-aerated, well-drained soil with a good balance of organic matter, nutrients, and microbial life will support faster decomposition. Conversely, compacted or poorly drained soils slow down decomposition.

Environmental Factors: Environmental conditions such as rainfall, sunlight exposure, and air circulation can influence decomposition rates. Higher rainfall can leach nutrients from the chips and accelerate decomposition, while prolonged exposure to direct sunlight can cause the chips to dry out and decompose more slowly.

In general, spruce wood will break down more slowly compared to softer woods like pine or cedar due to their denser nature. It can take anywhere from several months to a few years for spruce chips to decompose fully. For instance, thicker chips will take longer to break down than smaller, shredded chips.

As the spruce chips decompose, they contribute organic matter to the soil, improving its structure and fertility. However, during the decomposition process, nitrogen is temporarily tied up by the microorganisms breaking down the wood, which can lead to a slight nitrogen deficiency in the soil.

To counteract this, you can add nitrogen-rich fertilizers or use a balanced compost or organic fertilizer when incorporating spruce chips into the soil.

It’s important to note that, as spruce chips are decomposing, they can still provide some benefits as a mulch layer, such as weed suppression and moisture retention.

Therefore, many gardeners choose to top up the mulch layer with fresh chips to maintain these benefits while allowing the older chips to break down gradually over time.

Frequently Asked Questions

  • Do Spruce Wood Chips Retain Moisture Well?

Yes, wood chips, including spruce wood chips, have good water-retention properties. When applied as a mulch layer, they can help reduce evaporation from the soil surface and slow down moisture loss, thus keeping the soil consistently moist for plant roots.

  • How Should Spruce Chips Be Applied To A Garden?

Spruce wood chips should be applied as a mulch layer around plants, leaving a gap around the base of the plants to prevent excessive moisture buildup. It’s, therefore, crucial to avoid pilling the wood chips directly against the stems or trunks of plants, as this can create a moist environment that may encourage disease or rot.

  • Can Spruce Wood Chips Help Regulate Soil Temperature?

Yes, wood chips act as an insulating layer, helping to regulate soil temperature. They can keep the soil cooler during hot summer months by reducing heat absorption from direct sunlight. Additionally, they provide some insulation during colder weather, protecting the soil from extreme temperature fluctuations

  • Are There Any Precautions When Using Spruce Chips Near Young Or Newly Planted Trees?

When using spruce wood chips near young or newly planted trees, it is important to create a mulch-free space around the base of the tree.

This helps to prevent excessive moisture retention and potential rot or disease issues near the trunk. Also, leave a gap of a few inches around the base of the tree without any wood chips.

  • How Often Should Spruce Wood Chips Be Replenished in the Garden?

The longevity of spruce wood chips as mulch can vary based on factors such as climate, rainfall, and the size of the wood chips. Generally, it is recommended to replenish wood chip mulch every 1-3 years as they break down and decompose.

Hoover if the mulch layer becomes thin or begins to degrade, you can add a fresh layer to maintain its benefits.

  • Can Spruce Wood Chips Attract Pests Or Insects

Spruce wood chips are generally not attractive to pests or insects. However, like any organic mulch, they can provide shelter for some pests, such as slugs or snails. Therefore, regular inspection and control measures, if necessary, can help prevent any potential pest issues.


In conclusion, mulching is a fundamental practice in gardening that offers numerous benefits for plant health and soil management. Also, there are different types of organic mulches including bark and wood chips.

However, when selecting a mulching material, gardeners must consider factors such as plant requirements, soil type, climate, availability, and aesthetics. So…

Are Spruce Wood Chips Good for Garden

As discussed earlier, spruce wood chips can be a beneficial addition to your garden under certain circumstances. Even better, they offer several advantages such as weed suppression, moisture retention, and temperature moderation.

Further, the acidic nature of spruce wood chips makes them particularly suitable for acid-loving plants like blueberries, rhododendrons, and azaleas. However, it is important to consider some potential drawbacks as well. For example, spruce wood can lower soil pH, which may not be suitable for all types of plants.

Additionally, the decomposition process of wood chips can temporarily deplete soil nitrogen levels, so supplemental nitrogen fertilization might be necessary.

Therefore, if you consider using spruce wood chips in your garden, it’s crucial to evaluate your specific gardening needs and the plant species you intend to cultivate. Also, conduct a soil test to determine the current pH level and nutrient content of your soil.

So, if your garden already has acidic soil or grows acid-loving plants, spruce wood chips can be a valuable organic mulch option. However, if your soil is alkaline or you are cultivating plants that prefer neutral or alkaline conditions, it’s advisable to explore alternative mulching materials.

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