Photo: Sarah Wolfskehl

About Black Earth Compost

Our mission is to nourish the soil to grow healthy plants in Massachusetts, with an emphasis on food production by any and all!  Made in small batches, our compost is without grass clippings but instead utilizes the riches of a bounty of food scraps.

Compost is an excellent soil amendment to add to your yard for soil and plant health. Use it as a mulch for moisture retention, mix it into the soil before you plant, or topdress your lawn, trees and shrubs to provide added nutrients and organic matter.



Our compost is rich in humus, nurtures beneficial micro-organisms, is free of any viable weed seeds, and contains an abundance of immediate and slow release nutrients.

  • A Broad Range of Ingredients to support a bio-diverse compost
  • No Grass Clippings that contain herbicides, pesticides, and insecticides
  • Free of Weed Seeds
  • Lab tested for optimal composition (scroll down for details)*
  • Screened to 5/8ths inch 
  • Made in New England! Our compost sites serve as local sources of nutrients, making our state more resilient.
  • Our compost does come from community sources, which means it may contain some plastic and trash.  We do our best to keep this to a minimum.  This is the tradeoff to getting the rich nutrients contained in food scraps.


Lab Analysis - We have our compost tested at University of Maine each year for nutrients, pH, salts and C:N ratio. Additionally we test it for heavy metals (lead, nickel, cadmium, chromium, zinc, copper, and arsenic).

Plant Trials - We believe that plants don’t lie, and we know that analytical reports from laboratories won’t tell the whole story. That’s why we grow vegetables, fava beans and clover in our compost in a controlled plant. Clover and fava beans for the presence of persistent herbicides, using published bioassay protocols, and vegetables to show general vigor as they are heavy feeders.

BiologyWe test the compost for communities of bacteria, fungus, protoctist and nematodes. We tend to be a bacterial dominated compost, but over the long term fungal populations establish.  Our compost is great for making compost tea. 

Email or call 978-290-4610 ext. 3 if you have questions.

A note on pH: Compost normally shows pH 7 to 8 if it is rich in nutrients (especially for food scrap composts). This does not mean that it is going to dramatically send your soil’s pH sky high. The high pH of compost is attributed to the initial pool of 'ready to go' soluble nutrients. After that, the pH comes down to between pH 6 to 7. The compost will continue to release nutrients as the organic matter decomposes over the season.

Nutrient Lab Test Plant Vigor /
Herbicide Trials
Food Web Test Food Safety
Modernization Act
2024 Compost 2024 Herbicide Trial
2024 Plant Vigor
2024 Compost Coming Soon
2023 Compost
2023 Compost
2023 Compost 2023 FSMA Report for Farms
2022 Compost
2022 Compost
2022 Compost 2022 FSMA Report for Farms
2021 Compost
2021 Soil
2021 Soil - 1
2021 Compost - 1
2021 Compost - 2
2021 Compost - 3
2021 Compost 2021 FMSA Report for Farms
2020 Compost
2020 Soil
Not documented 2020 Compost
2020 FSMA Report for Farms

Heavy Metals: This graph shows metal content found in our compost and soil blend compared to state thresholds.  View 2023 Heavy Metal Analysis.

2024 Report of Annual PFAS Analysis: This report shows the content of fluorinated compounds found in our compost compared to state thresholds and other contaminated and non-contaminated soils. Note that our compost meets the criteria to be used in the state's strictest use case: compost can be used on a farm that sits over a drinking water supply and grows food where children are present. View our 2023, 2022 PFAS Lab Analysis. For more information on PFAS in our everyday lives and a podcast discussion with head composter Andrew Brousseau visit Moving the Needle.

*Some plastic such as fruit stickers and wrap may be found in the compost because we are sourcing the food scraps from the community.


    Building Local Resiliency With Food

    We proudly support community food initiatives and farms with raised beds, compost and soil to grow more food from food scraps.

    With the support of our customers, we offer compost at a reduced rate to local farms. 10 cents of each bag of compost sold goes to our FarmWorks program.

    Learn more about our raised bed gardens and find a FarmWorks Farm to buy produce from to complete the loop.

    Farm and Community Partnerships

    Our Compost Facilities

    Our compost is made at three facilities through out New England. These centers serve as local nutrient recyclers, sourcing material sustainably from the community, to be returned to the community. Reducing our need for imported synthetic fertilizers and making our state more resilient.

    Check 'em Out