TAGRO Nutrients Measured Annually
A&L Great Lakes Laboratories, Inc., tests biosolids produced at Tacoma's Central Wastewater Treatment Plant every year to determine the level of plant nutrients. The chart below lists 2019 averages, which are not guaranteed as with commercially produced fertilizers because TAGRO Mix, Potting Soil, and Aged Black Bark are organic products.
|
Total Nitrogen
|
1.39%
|
1.32%
|
.25%
|
|
Phosphorous
|
.69%
|
.64%
|
.0065%
|
|
Potassium
|
.09%
|
.15%
|
.088%
|
|
pH
|
8.2
|
6.7
|
5.0 to 8.0
|
Learn more about how we make and monitor the safety of TAGRO.
Technical Report
2004 Washington State University Cooperative Extension study: Suitability of Recycled Organic Materials as Growing Media, Micronutrient, and Phosphorous Sources for Container Nursery Stock Production
This report details the use of yard debris, biosolids and animal manure composts as growing media, paying careful attention to each product's use of water and nutrients. Recycled yard debris, dairy manure compost, TAGRO, Douglas fir bark and GroCo were used to grow rhododendron and lilacs according to standard nursery practices. TAGRO was deemed a sufficient growing media.