For years, gardeners have turned to dyed red or black mulch to bring their colorful landscaping vision to life.
But do dyed mulches carry any risks or drawbacks? Are there any precautions you should take to handle mulch safely?
The answer is that colored mulches may harbor dangers, but perhaps not for the reasons you’d expect.
In this article, you’ll learn about the dyes and wood products used to produce colored mulch. We’ll also look at ways to choose safe colored mulch options and proper usage tips.
Most mulch producers use these compounds to add vibrant red or black color:
Red mulch: Iron oxide
Black mulch: Carbon-based colorants
It’s a common misconception that the dyes used to create colored mulch are to blame for any potential toxicity. In reality, there’s no evidence that the dyes commonly used for red or black mulch have any negative effects.
Here are the details.
Iron oxide is essentially rust. It’s derived from iron that has undergone the oxidation process from air exposure.
Iron is an essential nutrient that enables plants to produce chlorophyll and process oxygen. As red mulch decomposes, iron oxide enters your soil and may help encourage plant growth.
Carbon-based colorants are organic dyes made from carbon molecules or atoms.
Aside from their use in colored mulch, these dyes are also present in several common household items:
Here’s where the chance for danger comes in.
Many mulch manufacturers produce black and red mulch from recycled wood products. Old wood typically has a dry, porous surface that readily accepts dye.
These materials could include:
- Shipping pallets
- Discarded construction materials
- Sawmill by-products
The concept of recycling wood into mulch seems like a great idea. Unfortunately, some of these materials could harbor dangerous substances. The biggest concerns are chromated copper arsenate and chemical residues.
Chromated Copper Arsenate
Chromated copper arsenate (CCA) is a form of the poisonous element arsenic.
Manufacturers used CCA in the production of pressure-treated wood from the 1940s until the year 2003. Most of these CCA-contaminated wood products should be out circulation by now. Nevertheless, there is still a risk that colored mulch could contain old CCA wood.
Some dyed mulches contain pieces of retired shipping pallets. These pallets themselves may be free of CCA. However, they may have carried hazardous chemicals or been otherwise exposed to toxins in the past.
In much the same way that old wood absorbs dye, it can also easily absorb chemicals.
Staying Safe With Red Or Black Mulch
So do these potential dangers mean you need to avoid red or black mulch like the plague?
Keep in mind that not all dyed mulch contains contaminants. What’s more, the risks should continue to drop as fewer pieces of CCA-treated lumber are in existence.
Below are 5 tips to brighten your landscape in the safest way possible.
1. Spend Time in Research
Lumber from these sources carry the highest risk for CCA:
- Home renovations or demolitions
- Torn-down decks
- Other construction by-products
If possible, choose a brand that doesn’t use this type of recycled wood. You may need to contact the manufacturer with your questions.
Note: Even if the mulch supplier doesn’t use recycled construction materials, they may still use shipping pallets. It’s extremely unlikely that you’ll be able to find out the pallets’ history of chemical shipments.
2. Wear Gloves
Avoid touching red or black mulch with your bare hands when applying it.
Wear a pair of sturdy work gloves, and make sure to wash well when you’ve finished the job.
3. Don't Use Red or Black Mulch in Play Areas
4. Keep Pets Away
Whether it’s your cat chasing a mouse into the garden bed or your dog satisfying the urge to dig, your pets may disturb mulch more than you’d expect.
Due to their smaller size, your pet could be at higher risk for ill effects from chemical exposure.
Consider putting up protective fencing around areas that contain red or black mulch. Not only will your pet stay safer, but your mulch can stay in better condition, too.
5. Don't Use Dyed Mulch in Vegetable or Fruit Gardens
It’s safe to say that you probably don’t want harmful chemicals making their way into your food. As such, don’t use red or black mulch in any area where you grow edible plants.
Instead, consider using compost as mulch to grow healthy, safe fruits and vegetables.
For more tips on how to use mulch in your garden or landscape, visit our Mulch Mastery guide.
Red or black mulch protects plants, shrubs and trees while adding an instant pop of color to your landscape.
However, dyed mulch can harbor some dangerous elements. While there can be appropriate uses for red or black mulch, you’ll need to plan thoughtfully and use extra care.