By Ron Alexander
Q: Why is there “Wood” in the Bloom Blends?
Fresh Bloom, DC Water’s Class A Exceptional Quality biosolids product, is a favorite of farmers, soil blenders and contractors alike, being a great source of both plant nutrients and organic matter. However, it is not the most convenient product for landscapers, turf managers and homeowners to utilize. For this reason, DC Water and BlueDrop developed their Woody Blend and Sandy Blend products.
The blended Bloom products contains less moisture, making them easier to handle, spread and blend in gardening, landscaping and turf applications. Aside from making Fresh Bloom easier to handle, the use of a woody type material in the Bloom Blends helps to capture the ammonia-nitrogen found in the Fresh Bloom. This allows the nitrogen to be converted into more plant beneficial forms and not be lost (through volatilization). Finally, the woody materials dilute the nutrient content of the Fresh Bloom, making the Woody Blend similar to compost products in usage and application rates.
It should be noted that the term Woody in the name Bloom Woody Blend is a misnomer. Neither Bloom Blend contain sawdust or woodchips (heartwood), they contain ground bark fines, which are typically aged for several months. Ground bark is a much more suitable input into soil amendments and growing media. The ground bark used on the Bloom Blends possesses a lower carbon to nitrogen (C:N) ratio, so it won’t rob nitrogen from the soil, and is higher in lignin content (lower in cellulose), making it more long-lasting in the soil.
Inner part of trees, sawdust and wood chip possess a C:N ratio of 200-400:1 and above (possibly over 1,000:1); whereas the bark find used in Bloom blends possesses a C:N ratio of approximately 60:1.
Ron Alexander is a horticulturist and the President of R. Alexander Associates, Inc., a consulting company specializing in product development for organic recycled products. He has over 35 years’ experience working with organic recycled products in the landscaping industry. He is a Landscape Architect CES registered trainer, has written and presented over 500 papers, and has authored several state and national specifications. Ron was also the co-manager of the US Composting Council’s Seal of Testing Assurance Program (national compost testing program).