Warning: Potentially Hazardous Mulch

Mulch was mentioned on the Rosarian’s Corner and it reminded me that I should share this warning that was circulated by our area Master Gardeners. They are advising everyone to be careful when getting mulch this year, particularly when buying the inexpensive bagged mulch at the big box stores. Here is the exact text of the message I received:

If you use mulch around your house be very careful about buying mulch this year. After the hurricane in New Orleans many trees were blown over. These trees were then turned into mulch and the state is trying to get rid of tons and tons of this mulch to any state or company who will come and haul it away. So it will be showing up in Home Depot and Lowes at dirt cheap prices with one huge problem; Formosan Termites will be the bonus in many of those bags. New Orleans is one of the few areas in the country were the Formosan Termites has gotten a strong hold and most of the trees blown down were already badly infested with those termites. Now we may have the worst case of transporting a problem to all parts of the country that we have ever had. These termites can eat a house in no time at all and we have no good control against them, so tell your friends that own homes to avoid cheap mulch and know were it came from.

I think it’s a good warning and something I wouldn’t have thought of. I may skip freshening my mulch this year.


Actually, this is apparently a hoax. Please feel free to read about it if you like:

From the Mulch and Soil Council[/url]

From the Louisiana Department of Agriculture and Forestry[/url]

From the National Plant Board[/url]

From the Snopes.com Rumor Website[/url]

From Texas A&M Extension[/url]

From Louisiana State University[/url]

Another article from Louisiana State University[/url]


Thank you for the correction. I try very hard not to perpetuate these kinds of hoaxes, and I’m embarrassed that I unwittingly did. I’m surprised that the Master Gardeners are putting this out.

At any rate, thanks for nipping it in the bud here and my apologies.


Don’t be embarrassed, Alicia, it’s not really a hoax, but rather more of an exaggeration. It’s true there could be a potential problem but the reality is it’s probably (not definitely) under control. A ban on an item doesn’t necessarily prevent it from entering the ‘food chain.’ Personally, I would take the information seriously but also not be too concerned about it. I highly doubt that places like Home Depot will be buying their mulch from sleezy dealers, but cheap mulch from unknown sources might be a cause of concern. Just my $.02.

The hoax is rather in the gross overblowing of the problem and in the implication that inexpensive mulch at box stores is more dangerous than any other. Everyone should examine their commercial mulch for anomalies, but then, we should always be doing that anyway. I agree with Judith, there’s nothing to be embarrassed about!

Dangerous mulch has happened before to be sure, though. For example, a county in Washington used some chemical on their lawns for a brief period in time. Well, the recycled… Oops. Dead plants in the local area. Geez, I wish I remembered the particulars. My old hort. teacher told us this story from when he was an extension agent.

As I recall, Milorganite had a cadmium problem for a while in the '70’s. If memory serves me right, it was made out of polluted sewer sludge from Milwaukee. Lots of people used it on their veggie gardens. And cadmium doesn’t leach. Bad news.

I purchased topsoil specified for vegetable garden about 10 yrs ago. It almost certianly contained some kind of herbicide because everything was stunted. I grow everything organically so it was not a fun experience. Just because something is labeled one way doesn’t always make it so unless certified by a reputable source. I’m glad to be reminded to be careful. Robyn


I don’t think Milorganite was never intended to be used on a consummable crop. Decorative and turf plantings are approved, but edible crops are not.


In 1879, the City of Milwaukee was directed to “clean up its act”, that is to provide adequate sewage treatment and disposal. At that time, all of the sewage produced was dumped into one of Milwaukee’s three rivers; the Milwaukee, Menomonee, and Kinnickinnic Rivers, eventually flowing directly to Lake Michigan. Then, as now, all of Milwaukee’s drinking water came from Lake Michigan which still serves as a popular recreation resource.

In 1913, the Legislature of Wisconsin passed an act authorizing the City of Milwaukee to create a sewerage commission charged with the responsibility of cleaning up the waterways. That same year, a chemist in Birmingham, England, was experimenting with the biosolids in sewage sludge. Air was allowed to bubble through wastewater for a period of time. When the air was turned off, and the mixture settled, the water was purified. This was the beginning of the activated sludge process.

The Milwaukee Sewerage Commission’s laboratory studied the new process, and formally adopted it for use on December 31, 1919. Plans were developed and in 1921 interceptor sewers were installed to connect to municipal sewers which enabled all wastewater treatment to be completed at a central location. Jones Island, on the shore of Lake Michigan, was chosen for that site and in 1923 construction began on the world’s first large scale activated sludge plant at a cost of about $15 million. In 1974, The Jones Island Wastewater Treatment Plant was named a National Historic Engineering Site by the American Society of Civil Engineers because the design and functionality of the plant were revolutionary.


The main purpose of the Jones Island Wastewater Treatment Plant was to produce clean water, and that remains the most important environmental mission of the Milwaukee Metropolitan Sewerage District (MMSD) today. Yet, the staff at MMSD knew that besides clean water, they also were faced with a significant disposal problem of the biosolids left from the activated sludge process. They had the vision, even as early as the 1920’s, that not only could the solids not be put back into the waterways, but at some point in time, landfill space would be scarce and not an environmentally favorable option. The MMSD established a fellowship at the University of Wisconsin College of Agriculture, under the direction of Professor Emil Truog, to investigate uses of activated sludge as a fertilizer. O.J. (Oyvind Juul) Noer was named as the fellow to carry out the work.

Noer determined that the average nutrient analysis of the material was 6.2 percent total nitrogen, with 5.17 percent being water insoluble nitrogen (83% WIN); 2.63 percent available phosphate (P205) and 0.4% soluble potash (K20). In his literature review, Noer found that as far as available nitrogen was concerned, this material closely resembled in its general characteristics the so-called high grade organic nitrogenous fertilizers and gave superior growth results compared to manures and chemical fertilizers of the time.

After experimenting with field crops and vegetables such as corn, potatoes, sorghum, cabbage, cauliflower, tobacco, tomatoes and muskmelon, O.J. Noer turned his attention to use of the organic fertilizer product on lawns and found it superior and one-third the cost of other fertilizers commonly used at the time. Additionally, it provided two distinct advantages; first, there was no danger of burning the turf even with misapplication and second, it produced a dark-green, dense turf without causing excessive top growth.

Noer then turned his attention to golf courses. Initial test plots were developed at Blackhawk Country Club and Maple Bluff Country Club in Madison, Wisconsin. Other plots were established at Bluemound Country Club, Ozaukee Country Club and Milwaukee Country Club in the Milwaukee area, all displaying excellent results. Plots were subsequently established in Chicago, Detroit, St. Louis, Cleveland, and St. Paul. As the word among golf course superintendents spread across the country about this new organic fertilizer, and more research plots were established, O.J. Noer knew he had a commercially viable product. In 1925, the Sewerage Commission concluded that the disposal problem they faced could be solved by producing and marketing the fertilizer, and hired Noer as the fertilizer salesman.


Of course, any commercial product needed a name. In 1925, a contest to name the new organic fertilizer was advertised in the National Fertilizer Magazine. The contest ended September 1, 1925 with 233 names submitted. First prize, and a check for $250, was awarded to McIver and Son of Charleston, South Carolina, for their entry “Milorganite”, derived from MILwaukee ORGAnic NITrogEn. Now with a name and an identity, the Sewerage Commission began taking orders for Milorganite in late 1925. Commercial production of Milorganite began about August 1, 1926. By the end of the year, about 5,500 tons of fertilizer were in inventory with orders for 2,500 tons.

To help stimulate sales, 5,000 booklets and 10,000 flyers were printed describing Milorganite. Also, an exhibit was arranged at the International Golf Show held in Chicago in late March, 1927. These efforts, along with the good fortune of introducing Milorganite as a turfgrass fertilizer just as the game of golf was experiencing a boom in popularity, propelled Milorganite into the position it holds today, the nation’s premier organic fertilizer. In 1927, 23,555 tons of Milorganite were sold. By the mid-1930’s, production was about 50,000 tons, selling for up to $20 per ton, and production could not keep up with demand. At that time, most Milorganite was sold to fertilizer companies for blending with other Nitrogen-Phosphorus-Potasium (N-P-K) sources, and very little was sold into the specialty fertilizer market.

Research continued and in the mid-1930’s, O.J. Noer established a soils lab to aid his studies. This lab was the first soils lab established exclusively for turfgrass. Through his work in the lab, Noer pioneered much of the methodology used in modern labs, including sampling depths and techniques, as well as laboratory procedures. Additionally, Noer determined through clipping analysis that the basic nutrient ratio in plant tissue was 3:1:2 (Nitrogen: Phosphorus: Potassium) instead of the 1:4:2 originally thought. From these studies came basic Milorganite fertility recommendations still used today. These recommendations have stood the test of time and still fit well even in the low nitrogen fertility programs commonly used in modern turf management regimes.

As Milorganite grew in popularity, the demand for skilled agronomists and turf specialists became greater. Charlie Wilson was added to the Milorganite staff in June of 1955 (he retired in 1978), Jim Latham joined in 1960, retiring in 1984 to rejoin the USGA Greens Section Staff as the Great Lakes Regional Director. Bob Welch came aboard in 1962, retiring in 1986. The staff today still emphasizes technical expertise, employing scientists in the production, analytical and sales & marketing areas.

Over the years, Milorganite has tried to adapt to market changes. While in 1926, most of the Milorganite was sold in bulk, by the mid-1930’s it was also packaged in 25, 50 and 100 lb. bags. In 1955, packaging changed to offering 40 and 80 lb. bags, in the 1970’s in 20 kg bags as the movement to metric in the U.S. was at its peak, and today it is sold in a distinctive 40 lb. bag exclusively for the retail market, 50 lb. bags for the professional market, and reusable bulk bags for large area applications, such as golf course fairways and roughs, parks and sports fields. The bulk fertilizer blending market continues to be important to Milorganite across the country and Canada as other fertilizer companies find the nutrient analysis to be a valuable addition to their products.

Prices have also changed over the years. In 1926, Milorganite cost $14.00 per ton. In the mid-1930’s it had increased to $20 per ton, and by 1968, it had grown to $52.50 per ton. Increases in labor costs, handling, packaging, etc., have dictated further increases since then . However, the price of Milorganite has generally stayed behind the rate of inflation since its beginning in 1926.

Sound, practical agronomic research continues to be a top priority for the Milorganite staff today, just as it was for Noer, Wilson, Latham, and Welch. Milorganite has been included in and has helped fund many important research projects at universities across the country, especially in environmentally sensitive areas such as nutrient leaching and run-off, disease suppression characteristics of organic fertilizer products, and the affect of different fertility regimes and sources on irrigation requirements.


Thanks for the info, Meg. I did use Milorganite on a veggie garden back in the 70’s and the bag at that time didn’t say it wasn’t for use in vegetable gardens. I had many discussions with the company over that, with the end result being I either had to replace my soil completely, or keep the pH at neutral which would keep the cadmium from being absorbed by the plant.

I do use Milorganite now but on my roses only.