There is a lot of information out there about using colored mulch and the same question inevitably comes up... "Is dyed mulch safe?"
To answer this important question, we need to examine the ingredients of dyed mulch.
If you're buying bagged mulch, it's easy to read the label to find out this information. Purchasing mulch in bulk from your local garden center will require you to ask the imporant questions... "Where do you get your mulch?" and "What's in it?"
One of the most important factors in determining if dyed mulch is safe to use in your gardens is to understand what kind of wood makes up the mulch. Here's what you should know:
Ingredients Of Colored Mulch
The safety of mulch is not so much determined by the dye that's in it, but rather, the type of wood used in the product.
In order to make it as cheaply as possible and, therefore, reduce the sale price, some companies use scrap wood, including wood pallets, construction debris, and other wood scraps. This type of wood has often times been treated with preservatives such as creosote, but in addtion, chromium, copper and arsenic, which is known as CCA.
Obviously, these chemicals will leach into the soil, possibly harming plants and most likely be harmful to the environment. They should not be found in garden products.
In addition, when using scrap wood, because the quality of the final mulch product is not consistent in color and texture, dye is added to make it look more uniform and natural.
Needless to say, this type of wood should not be used in mulch and we woud advise you to stay away from it.
However, like everything in life, you only get what you pay for. People looking to save money might not care, or might not think to look at the ingredients list on the bag. We all know to look at the ingredients list on food labels but not mulch, right? Now you do and now you should.
It's a myth that all died mulch uses sub-par wood scraps that are "covered-up" and made to look better by adding dye. This is just not the case.
The mulch we use quite a bit, Earth Gro from Scotts, includes a statment right on the bag that says: "Free Of Construction Debris."
Look for statements like this or read the ingredients to find out more about what's in the mulch you use in your gardens.
What Is In Mulch Dye - The Answers You Want To Know
When trying to get answers to the question "is dyed mulch safe for use" you must not only look at the types of wood used, but the dyes as well.
Here's what we know...
There are 2 types of mulch dyes, each made from different compounds. both of them natural mineral.
Mulch dye is either carbon-based or iron oxide based - which is the most common one used. Without getting too scientific, iron oxide is a compound made up of iron and oxygen (think rust). As the compound oxidizes, iron is released into the ground, which is not considered toxic.
Have you ever been to the florist and seen beautiful neon colors of flowers? Iron oxide dyes are often used to dye these flowers and are used extensively for this purpose. What you may not know is the flower stems are dipped in the dyes and they are taken up by the stems until they reach the flowers. Fascinating, right?
On the other hand, there are some carbon-based (think charcoal) dyes used on mulch as well. These are similar to those used in ink and cosmetic products - so they are widely accepted for use.
The next question arrises, "Does the dye leach into the soil?" The answer is sometimes it could. Colorants that are not absorbed by the the wood would come off and leach into the soil. This happens to an even greater extent when the mulch has gotten wet but it also depends on the wood, how well it absorbed and the actual dye used as well.
You must keep in mind an important point. There are many dyes used in society today. From hair dye to tatoo ink and lots more. Dye used in mulch is just one more colorant that is used by society to help with certain problems that we think need fixing; that is, the look of the mulch.
Dyed mulch has come into vogue for that reason - society wants it.
As of this writing, there is no evidence that the dyes used to color wood chip mulch are toxic.
This might contrast to information you've seen elsewhere and here's what we have to say about that.
As you know, the internet can be full of information, some true, some not so true, even if written by well meaning individuals. In addition, different studies have been done with somewhat different results.
Only you can decide if you want to use dyed mulch.
Is Dyed Mulch Safe For Dogs?
We've heard people ask this question, although none of our clients have asked us about it.
We will state here that we are not qualified to give an answer to this question and wouldn't even begin to give you advise here.
Without question, the first thing you should do if you have a dog or dogs is to be sure the wood is not scrap construction materials and pallets that could be treated with harmful chemicals. This is plain common sense and now that you know it, be sure to read the label or know where your mulch comes from.
The best option if you're still unsure is to use an all natural mulch product.
One thing I can tell you for certain. We have used dyed mulch in our client's gardens for decades and many of them have dogs - some of them even digging in their gardens regularly and creating a mess. There has never been a problem with the health of our client's dogs because of the mulch we have used.
However, this is not to be considered as advice. You should check with your veternarion to advise you on this topic.
Is Dyed Mulch Safe? Look For The Seal Of Approval
Reputable mulch products are certified. You can look for a seal on the bag from the Mulch and Soil Council (MSC).
Founded in 1972, the MSC is a national non-profit trade association that has developed product certification programs for potting soils and mulch. See mulchandsoilcouncil.org/ for more information.
Mulches that display the MSC seal have been tested and found free of CCA. Big box stores and local garden centers stock MSC approved mulches so be sure to check for that.
As we mentioned there is no evidence that mulch dyes are harmful. In fact, since they are made from natural minerals, we think they are safe to use.
However, as you know with everything in life, there is nothing certain forever. We can only go by the current facts that come from testing these things.
We will continue to use dyed mulch until it is deemed unsafe. Until that time we answer the question of... "Is dyed mulch safe" with a yes. You'll need to make your own choice based on available information at the time.
For more information, here's a great resource:
https://ag.umass.edu/landscape/fact-sheets/colored-bark-mulch
To learn about the different types of mulch available, read this article.
To find out more about preparing your planting beds, we have more information here.
Happy gardening.
