Wood Chips, Mulches, Compost: What’s the difference?
Wood chips, mulches, and compost can all be very different, as each possesses distinct characteristics in terms of their composition, function, and application. There is sometimes confusion about what situations are most appropriate for each. Here at Blacklotus, we utilize all three for different scenarios and phases in the design, installation, and maintenance process. Today, we’re hoping to cover the basis of what each one is, their differences, how to use them effectively, and the benefits they bring to your garden. Whether you're a seasoned gardener or just starting, understanding the role of wood chips, mulches, and compost is essential for nurturing healthy, abundant, and vibrant landscapes.
Table of Contents
About Wood Chips
Wood chips are a versatile material often derived from chipped or shredded tree branches, trunks, and other woody debris. They’re commonly used in landscaping and gardening for a variety of purposes. Wood chips come in different sizes, ranging from small flakes and sawdust to larger chunks, and can be sourced from a variety of tree species, including hardwoods (e.g., maple, alder, cherry, apple, walnut) and softwoods (e.g., cedar, fir, pine, spruce). Wood chips are often a byproduct of the logging industry and can also be commonly sourced from arborists who have just completed a job.
One of the primary functions of wood chips is to provide mulch and ground cover in gardens and landscaping beds. They mimic a forest drift mulch layer and help retain garden soil moisture by reducing water evaporation and suppressing weed growth, which can compete with plants for water and nutrients. Additionally, wood chips slowly decompose over time, adding organic matter to the soil and improving its structure over multiple years.
In addition to their role as a type of mulch, wood chips can also be used for pathways and walkways in garden areas. Their natural appearance and texture make them an attractive and functional option for creating defined pathways that blend seamlessly with the surrounding landscape.
Be sure to stay away from wood chips that have been dyed with inorganic materials to appear red or black. Source organically when possible, as this ensures the wood chips are free from harmful chemicals and additives that could potentially leach into the soil and affect plant health. Opting for organic sources also promotes sustainable forestry practices and reduces environmental impact.
We have had the best results with arborist wood chips that have leaves and needles ground up in the material. As they break down over time they have a great positive impact on soil health. We favor them over any other mulch in most landscape settings.
About Mulch
Mulch is a general term for a material applied to the surface of the soil to conserve moisture, suppress weeds, and improve soil health. You will note wood chips are a type of mulch for example. It can consist of a variety of organic or inorganic materials, including wood chips, yard trimmings, straw, tree leaves, grass clippings, gravel, and shredded bark. Additionally, mulch can be made from synthetic materials like rubber or plastic though we would not recommend the use of these types of materials as they are damaging to the soils and natural environment. The use of naturally occurring materials that can break down without causing negative impact to your landscape are key.
Organic mulches, like wood chips and shredded leaves, break down over time, enriching the soil with nutrients and improving its structure. In contrast, inorganic mulches, like gravel, provide partial weed control and moisture retention but do not contribute to soil fertility. Applying cover-crop seeds such as rye or clover to bare soil also acts as a living, organic mulch and can also fix nutrients into the soil, such as nitrogen.
Mulch is a protective barrier between the soil and the environment, keeping soil cool and reducing soil erosion caused by wind and water. It also creates a habitat for beneficial soil organisms to thrive, such as earthworms and microbes, which play a crucial role in maintaining soil health and fertility. Soil is teeming with life with a teaspoon of healthy soil containing up to a billion microorganisms.
About Compost
Compost is a nutrient-rich soil amendment produced through the decomposition of organic matter, such as kitchen scraps, yard waste, and plant materials. It is created through a process called composting, in which organic materials are broken down by microorganisms, bacteria, and fungi into a dark, crumbly substance known as humus. There is nothing quite as beautiful as making compost from your own food scraps, coffee grounds, and yard scraps.
Compost is often referred to as "black gold" for its ability to improve soil fertility and structure, as well as increase moisture retention. It contains a wide array of essential nutrients, such as nitrogen, phosphorus, and potassium, that are slowly released into the soil, providing a very natural source of plant nutrition. Compost can also be amended with biochar, which is a form of charcoal produced from organic materials, to increase the soil's ability to retain moisture and nutrients, as well as improve its overall structure and fertility.
In addition to its role in enriching soil, compost can help suppress plant diseases and pests, eliminate the need for chemical fertilizers and pesticides, and promote healthy root development. It can be used as a top dressing for lawns and home gardens, incorporated into potting mixes for container plants, or applied as a mulch around trees and shrubs.
A big consideration for compost is that the particles are so fine, that “weeds” will often grow their way quite easily in areas where compost is left bare. This is the same with bare soil and is nature’s way of protecting the soil life within and beneath the soil surface. If you are laying out compost, always be sure to top with some sort of mulch layer such as straw or wood chips, to keep weed competition low.
When & Where to Use Each
Here are the best practices broken down for when and where to use wood chips, mulches, and compost.
Wood Chips
Do:
Use wood chips as a mulch around trees and shrubs to retain moisture and suppress weeds.
Apply wood chips to pathways and walkways in garden areas for a natural and attractive ground cover.
Dont:
Don't use wood chips from chemically treated or painted wood, as they may contain harmful substances.
Apply wood chips that touch structures or buildings, as they can attract pests and promote rot.
Apply wood chips too closely around trees, as the chips against the trunk can cause rot to occur. Keel all wood chips slightly away from the base of the tree.
Mulch
Do:
Use mulch around garden beds, trees, and shrubs to conserve moisture and suppress weeds.
Apply mulch in the spring or fall to help regulate soil temperature and protect plants from extreme weather conditions.
Choose organic mulches, such as straw or leaves, for areas where soil improvement is desired.
Dont:
Use mulch directly against plant stems or trunks, as it can promote rot
Avoid using colored or dyed mulches, as they may contain chemicals harmful to plants and soil organisms.
Don't apply mulch too thickly or cover an actual plant, as it can suffocate plant roots and prevent water from reaching the soil.
Compost
Do:
Use compost as a soil amendment to improve soil fertility, structure, and moisture retention.
Make your own compost! Use a small compost bin inside your kitchen and transfer it to an outside compost pile to work its magic and break down.
Apply mature compost to flower beds, perennial beds, vegetable garden and planting holes before planting to provide a nutrient-rich environment for plants.
Choose compost made from a diverse mix of organic materials for maximum soil benefits and plant nutrition.
Incorporate with biochar to improve soil quality and moisture retention.
Dont:
Use compost that is not fully decomposed, as it may contain pathogens or weed seeds.
Avoid applying compost in layers thicker than 6”, as it can create an imbalance in soil nutrients and hinder plant growth.
Don't rely solely on compost for plant nutrition, as it may not provide all the essential nutrients needed for optimal growth.
To Sum It All Up…
Knowing the difference between wood chips, mulches, and compost can be powerful. Each of these materials plays a crucial role in nurturing healthy plants and ecosystems in a successful garden. Wood chips provide long-term benefits as a durable and low-maintenance finish layer mulch also providing immediate protection against weeds and moisture loss from the sun as with other mulches. Compost, with its rich nutrients and microbial activity, acts as a natural fertilizer, enriching the soil and enhancing its structure. By understanding when and where to use each of these materials, gardeners can create thriving landscapes and grow them abundantly into the future!
