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Get ready to dig into the details, use cases, pros, and cons of hardwood mulch, wood chips, and three types of mulch made from bark - bark nuggets, bark dust, and bark mulch.
All are popular types of organic mulch, and all but one (bark dust) are easy to get your hands on and easy to work with.
TL;DR? no worries! Scan the FAQs below and get the info you need in a hurry.
Just FYI, there are other mulch options and tips to know regarding what kinds of mulch are best for different climates and soil types, how to apply mulch to best effect, and more.
After taking in the info here, maybe hop over to our comprehensive guide, "What Does Mulch Do? Basics, Benefits & Best Practices", and get even more mulch-related intel to make the best decision for your project and outdoor space.
Bark, Wood Chips & Hardwood Mulch: Making the Right Choice for Your Garden's Health
Just to level-set, all three of the mulches investigated here are organic mulches.
Organic mulch is a top dressing that you layer over the soil in your garden beds, paths, flower beds, vegetable gardens - wherever you want to:
- eliminate weed growth and insert weed control;
- stop soil erosion;
- build soil quality;
- stop water loss through evaporation and bolster soil moisture;
- regulate soil temperature to protect plant roots;
- add texture and color to your landscape design.
Organic mulch is great in gardens because it supplies nutrients to the soil as it decomposes. It's the best mulch to apply if your priority is to promote plant growth and soil health.
(Learn much more about organic - and inorganic - mulch in our "What Does Mulch Do?" post.)
Using Bark As Mulch
According to the Mulch and Soil Council, bark is "The corky exterior covering of trees, including the cambium, with a maximum wood content (interior xylem) of 15%." (Source)
Mulches that are made from or include bark are bark nuggets, bark mulch, and bark dust.
Bark Nuggets
Bark nuggets that we typically buy at box stores and garden centers are made from the bark of trees such as fir, pine, redwood, and spruce woods. The bark is removed during the lumber milling process. (Source)
You can get nuggets in large and small chunks. Pine bark nuggets are a common option though there are other Western bark nuggets from conifer (cone-bearing) trees found in North America's western region.
Bark Nugget Pros
- Tend to last years, especially the variety that comes in bigger chunks.
- Maintain their natural color and don't turn grey like other organic wood mulches.
- Some bark nuggets, such as pine bark nuggets, are great for plants that thrive in acidic soil.
- Maintain their shape and don't compact.
- Are widely available.
Bark Nugget Cons
- Better for areas where you won't need to move them like around a tree trunk and under shrubs.
- Float in water so it's a good idea to use them on level ground where they won't be submerged in water or washed away in heavy rains.
- Wood loving pests like termites can set up house in bark nuggets.
Bark Mulch
Bark mulch is made from the aged bark of hardwood trees such as oak, hickory, ash, and hemlock, and softwood trees such as fir, pine, cedar and spruce.
Bark mulch may contain nuggets or chunks but it's shredded, sometimes double-shredded, and so also has a stringy, more broken down quality.
Bark Mulch Pros
- It's widely available.
- The different woods used offer different colors and hues naturally, not through dye, so you can choose from different colors to suit your garden design.
- Since it's shredded it will break down faster than bark nuggets.
Bark Mulch Cons
- The bark mulch of hardwood trees can add alkilinity to your soil which your acid-loving plants won't like.
Bark Dust
New to me (but not to Pacific Northwest gardeners and landscapers) is bark dust.
Bark dust is commonly made from the bark and wood of cedar, fir, pine, spruce, and hemlock trees that have been ground into small particles to fine granules. (Source)
You can spread the stuff yourself but you may want to grab a mask. Due to its fine profile, many companies use blowers to put bark dust where it's needed.
Bark Dust Pros
- The different woods used offer different colors and hues naturally, not dyed. Choose from different colors to suit your garden design.
- It can provide a soft, splinter-free landing in children play areas.
Bark Dust Cons
- DIY-able but perhaps not super DIY friendly.
- Widely available in the Pacific Northwest; not as common in other parts of North America.
Using Wood Chips As Mulch
Wood chips are an organic material made from hardwoods and softwoods.
Wood chip mulch is usually lower in cost than shredded wood or bark options.
FYI, it's possible to get your hands on wood chips at no cost if you know where to look and who to ask.
If you are successful in obtaining a free pile of wood chips, note that it might contain parts of the whole trees - chipped trunk, bark, branches, leaves, needles, pine cones....
This is because free wood chips are a by-product of tree trimming and removal work. The chipping makes whatever was chopped down easier to transport and dump.
Wood Chip Pros
- Affordable - can be obtained inexpensively or free.
- You help local small landscaping and tree trimming companies save on gas and landfill fees when you take wood chips off of their hands.
Wood Chip Cons
- If it's the free stuff, you have no control over what you get or when you get it.
Using Hardwood Mulch
Typical hardwood mulches - the kind you find at Home Depot and other stores and garden centers for about $3 to $4 per bag often dyed red, black, or brown - are organic mulches that are a by-product of lumber production.
You may have heard rumours that there could be wood pallets and old furniture in your bag of mulch.
Well, hardwood mulch can include shredded recycled wood such as wood pallets, furniture, and decking. This is a cause for concern in that you can't know what that wood was coated or treated with. For example, if wood pallets were used in chemical transport, chemicals may have leaked onto them and could be in your bag of mulch.
If you're buying mulch made from recycled wood make sure it's safe. Look for the Mulch & Soil Council's seal on the bag to verify that your mulch doesn't contain contaminants.
Hardwood Mulch Pros
- Mulch made from recycled wood is eco-friendly.
- Affordable.
- Widely available.
- Choose from different colors to suit your garden design.
Hardwood Mulch Cons
- Can include woods that were chemically treated.
Frequently Asked Questions (FAQs)
What are the main differences between bark mulch, hardwood mulch, and wood chips?
Bark mulch is made from the outer bark of trees, often from hardwoods like oak or softwoods like pine. It decomposes slowly, providing long-term soil coverage and moisture retention. Hardwood mulch is derived from the inner wood of hardwood trees; it decomposes faster than bark mulch, enriching the soil with nutrients more quickly. Wood chips are comprised of chipped branches and trunks, offering a natural, rustic appearance. They decompose slowly, making them suitable for pathways and areas where long-lasting coverage is desired and are also beneficial in the garden.
Which type of mulch - bark mulch, hardwood mulch, or wood chips - is best for suppressing weeds?
Bark mulch, hardwood mulch, and wood chips are all effective at suppressing weeds by blocking sunlight and creating a physical barrier. However, finer-textured mulches like hardwood mulch may provide more uniform coverage, potentially offering better weed suppression.
How do bark mulch, hardwood mulch, and wood chips affect soil nutrients?
All three types of mulch break down, enriching soil with nutrients and improving soil structure. Bark mulch and wood chips decompose more slowly, gradually adding organic matter to the soil. Hardwood mulch breaks down more quickly, supplying nutrients to the soil ecosystem faster.
How long do bark mulch, hardwood mulch, and wood chips last before needing replacement?
Bark mulch has a slow decomposition rate and can last several years before needing replenishment. Hardwood mulch typically requires replenishment every 1-2 years as it decomposes faster. Depending on the size of the chips and environmental conditions, wood chips can last up to five years.
Which mulch is more cost-effective: bark mulch, hardwood mulch, or wood chips?
Wood chips are typically more affordable and can often be obtained for free. Hardwood and bark mulches vary in price but are generally more expensive than wood chips.
How do bark mulch, hardwood mulch, and wood chips impact soil pH?
Certain types of bark mulch, like pine bark, can increase soil acidity, benefiting acid-loving plants. As it decomposes, hardwood mulch can make the soil more alkaline, which may not be suitable for acid-loving plants. In general, wood chips have a neutral effect on soil pH, but this can vary depending on the wood source.
Can I use bark mulch, hardwood mulch, and wood chips around all types of plants?
While it's generally safe to use bark mulch, hardwood mulch, and wood chips in and around your garden, it's good practice to consider the specific needs of your plants. For example, acid-loving plants will likely do better with pine bark mulch, while hardwood mulch might not be ideal in this scenario due to its potential to increase soil alkalinity.
How should I apply bark mulch, hardwood mulch, and wood chips for best results?
When spreading bark mulch, hardwood mulch, and wood chips, aim for a 2-4 inch layer of mulch around your plants. Be sure to keep the mulch away from plant stems and tree trunks to prevent moisture buildup and potential rot. Check out many more tips on choosing and applying mulch in our comprehensive mulch guide.
So, Now You Know
Hopefully the info here has helped you sort through these common mulch options and you're now off to secure the perfect mulch for your application.
If you're still pondering your options, check out our comprehensive mulch guide which includes best practices for application, mistakes to avoid, and much more.
Also to note: there's a fast and easy way to contain all of that mulch you'll soon be spreading around. Check out 2xEDGE Staples and transform common lumber into easy to install landscape edging and garden borders - no digging or drilling.
Related Links You Might Like
What Does Mulch Do? Basics, Benefits & Best Practices
Cedar vs Cypress Mulch: Which is Better For Your Garden (& the Planet)?
Bagged vs Bulk Mulch vs FREE: Which is Best and Why? (Updated 4/3/2024)
How To Make a Mulch Bed in Your Garden (Easy DIY Guide)
