FAQs
Compost
- How is WM EarthCare™ Homegrown Compost made?
- Does WM EarthCare™ Homegrown Compost adhere to the requirements of the US Composting Council (USCC) Seal of Testing Assurance Program (STA)?
- Is WM EarthCare™ Homegrown Compost certified for organic use?
- What does the California Department of Food and Agriculture (CDFA) label connote?
- What is the average processing time from receipt of raw materials to compost sale?
- How do you control for foreign materials, like plastic bags and glass?
- How do I know it is safe to use in my yard?
- What is the best way to add compost to my planting beds?
- How often should I add compost to my soil?
- Can I start seeds or transplants in containers filled with compost?
- What are the benefits of food waste collection and composting?
- What is the difference between mulch and compost?
- If this compost is from green waste debris, will weeds begin to grow after I mix it in the ground?
- How much compost do I mix in the ground to grow my tomatoes?
- Can I use this compost as a compost starter for composting in my backyard?
- I have an area that is 20’x20’ and I need to rototill compost in the ground. How much do I need?
Mulch
- How is WM EarthCare™ mulch made?
- How do you control for metals and other contaminants?
- Can I earn LEED, Green Build, or Bay-Friendly points using WM EarthCare™ mulch?
- What is used to color the mulch and is it safe?
- Is there a mulch color that is better for my plants?
- How much mulch should I use in my planting beds?
- If I use more mulch, will it improve the soil’s water retention?
- How quickly does mulch deteriorate? Do I need to replace it often?
- Is mulch good for all plants, shrubs and trees?
- What’s the best time of year to apply mulch?
- Do you have information that tells me how Muir Woods Brown mulch is made?
- How long will the color last?
- What are the recommended applications for mulch fines?
- What is the minimum quantity for a custom color or screen size?
Compost
Q. How is WM EarthCare™ Homegrown Compost made?
A. The making of Homegrown Compost starts with you! Trimmings from your yard and food scraps from your kitchen are collected and then processed at our WM EarthCare™ Redwood Composting Facility in Novato, CA. Our facility is fully permitted and regulated by the County of Marin Local Enforcement Agencies (LEA).
Collected yard and food materials, known as feedstocks, are precisely ground and shredded to facilitate rapid decomposition by microorganisms. The feedstock is carefully blended to achieve the proper balance of carbon (C), also known as “browns”, with nitrogen (N), also known as “greens”, needed to feed hungry microbes that do the work of decomposition.
Compost feedstock is ground and placed in one of thirty-four covered aerated static piles (CASP) located on a 7-acre asphalt pad. Each CASP bay is equipped with a valve and flowmeter that allows the amount of air to be monitored by computer and optimized for each CASP. The goal is to provide enough air through the perforated pipes under the CASP to keep the decomposition aerobic but not so much air that the pile can’t heat to a temperature of above 131 degrees F. The microbes in a compost pile generate heat naturally as a by-product of their metabolism. We manage the heat generated to kill pathogens and weed seeds and degrade chemical compounds such as herbicides. After the compost has maintained a temperature of above 131 degrees F for at least 3 consecutive days (though normally it spend 3-4 weeks on aeration at these temperatures), it can be removed from aeration and cured. Curing, like aging a fine wine, gives the compost time to stabilize, mature, and cool. Curing is an important step in the production of our high quality Homegrown Compost. Our compost isn’t approved for sale until it’s been cured. At WM EarthCare™ our motto is, “We sell no compost, before it’s time.”
Q. Does WM EarthCare™ Homegrown Compost adhere to the requirements of the US Composting Council (USCC) Seal of Testing Assurance Program (STA)?
A. Yes! Our Homegrown Compost is recognized by the US Composting Council’s Seal of Testing Assurance Program (STA). The USCC, STA is a compost testing, labeling, and information disclosure program designed to provide consumers with the product information they need to get the maximum benefit from the use of compost.
The program was created in 2000 and is recognized by the leading compost research scientists in the United States.
Information about the science behind the development of the STA program and the various tests that are used can be found by visiting: http://compostingcouncil.org/?page_id=32
You can review and download the USCC STA Compost Technical Data Sheet for our Homegrown Compost by clicking here: (Download PDF)
Q. Is WM EarthCare Homegrown Compost certified for organic use?
A. WM EarthCare™ Homegrown Compost has earned the Organic Materials Review Institute (OMRI) listing for use in certified organic operations.
OMRI provides organic certifiers, growers, manufacturers, and suppliers with an independent review of products intended for use in certified organic production, handling, and processing. When a company applies for listing, OMRI reviews their products against the National Organic Standards. Acceptable products are OMRI Listed® and appear on the OMRI Products List. OMRI also provides subscribers and certifiers guidance on the acceptability of various material inputs in general under the National Organic Program.
Q. What does the California Department of Food and Agriculture (CDFA) label connote?
A. To receive the CDFA label on their compost, manufacturers must supply the CDFA with the types of feedstocks, lab analysis of feedstocks, and the names of feedstock suppliers. They must also agree to random CDFA inspections of their facilities and testing of their product by CDFA to verify nutrient claims.
Q. What is the average processing time from receipt of raw materials to compost sale?
A. Our science-based process can be managed to produce safe, stable, high quality compost in a matter of weeks or up to six months based on market demand. In practice, the actual composting time is not particularly important. Essential is that the composting period be sufficient to kill pathogens, parasites and weeds, degrade chemical compounds, and conserve nitrogen.
At WM EarthCare™ our motto is, “We sell no compost before it’s time.”
Q. How do you control for foreign materials, like plastic bags and glass?
A. Feedstock materials are inspected for compost suitability upon arrival at our Redwood facility in Novato, CA. We remove glass, metal, plastic and related inorganic materials through a mechanical separation process.
Our finished compost is mechanically screened to contain particles no larger than 3/8” in size.
Inert materials make up less than 1 percent of our finished Homegrown Compost.
Q. How do I know it is safe to use in my yard?
A. You can be confident that our WM EarthCare™ Homegrown Compost is safe for use in your yard, and around children and pets because it’s independently tested in accordance with nationally recognized guidelines.
Homegrown Compost is recognized by the US Composting Council’s Seal of Testing Assurance Program (STA). The USCC, STA is a compost testing, labeling, and information disclosure program designed to provide consumers with the product information they need to get the maximum benefit from the use of compost. The program was created in 2000, and is recognized by the leading compost research scientists in the United States.
Information about the science behind the development of the STA program and the various tests that are used can be found by visiting: http://compostingcouncil.org/?page_id=32.
You can review and download the USCC STA Compost Technical Data Sheet for our Homegrown Compost by clicking here: (Download PDF)
Q. What is the best way to add compost to my planting beds?
A. Compost can be added directly to vegetable and flower beds by incorporating 3–4″ of fresh compost into the beds to a depth of 6–8″ in the fall or spring using a pitchfork or spade. This method ensures that the nutrient-rich humus will be available in the root zone of your plants where they are most needed. Additional applications of compost mixed with aged manure can be utilized throughout the growing season in place of chemical fertilizers.
For larger landscape areas including lawns and play fields, compost should be applied at a rate of not less than 2 cubic yards per acre (1 ton) or more than 10 cubic yards per acre (5 tons) incorporated to a depth of 6–8″. An in situ textural analysis of the soil should be performed before arriving at a final application rate.
Q. How often should I add compost to my soil?
A. It’s best to perform large applications of compost—incorporated as a soil amendment—in either the fall or spring. A single major application will be sufficient in most cases. The annual application can be supplemented with monthly ground cover applications of compost as mulch during the growing season.
Q. Can I start seeds or transplants in containers filled with compost?
A. Starting seeds or transplants in pots using 100% compost is not recommended.
Compost in this case is the end result of a well-developed recipe. The percent of compost in a seed or transplant medium can vary widely. Blending compost with peat, coconut coir, or other components is routinely carried out to obtain the desired pH and soluble salt content of the mix.
The volume of compost will typically range from 10% to 50%, although it can be higher. For higher rates, the compost would need to be very mature and stable. Unless you are an experienced horticulturalist, you should not use more than 50% compost in any seed starter or transplant mix.
Q. What are the benefits of food waste collection and composting?
A. Adding food scraps to green waste increases the richness of the finished soil product. In addition, environmental models show that sending 45,000 tons of organic waste to be composted instead of buried in a landfill reduces greenhouse gas emissions by an estimated 44,000 metric tons per year CO2E (carbon dioxide equivalent): That’s comparable to keeping 8,000 cars off the road each year.
Compost also restores soil health, conserves water, reduces the use of chemicals, reduces air and water pollution, decreases reliance on oil reserves, and improves plant health. Finally, by removing the “wet” organic portion of the waste stream, the remaining waste is “cleaner.” This provides more potential opportunity for greater overall recycling.
Q. What is the difference between Mulch and Compost?
A. Mulch refers to any material (organic or inorganic) that is used as a ground cover. Mulch should not be incorporated into the soil. Compost, which is a type of organic mulch when used as ground cover, is distinct in that it is the result of the process of decomposition – typically aerobic (with oxygen) decomposition. Compost can be incorporated into the soil. When used in this way, compost is called a soil amendment.
Q. If this compost is from green waste debris, will weeds begin to grow after I mix it in the ground?
A. No. Our finished compost is free of pathogens, parasites, and weeds. During the composting process temperatures in our windrows become sufficiently high (above 130°F) to kill potential pests including weeds. To ensure the our compost consistently meets this standard, we participate in the U.S. Composting Council Seal of Testing Assurance Program.
Q. How much compost do I mix in the ground to grow my tomatoes?
A. Tomatoes and other vegetable crops should receive a compost application of 3–4″ incorporated to a depth of 6–8″. During the growing season, surface application of compost mixed with aged manure can be utilized in place of a chemical fertilizer.
Q. Can I use this compost as a compost starter for composting in my backyard?
A. Yes. WM EarthCare™ Homegrown compost can be used as inoculum in your backyard compost bin. Homegrown contains a diverse community of microorganisms that will jumpstart your home composting. Just add carbon (browns) and nitrogen (greens) at a ratio of 3:1 mixed with Homegrown compost and decomposition will begin. Remember to monitor air and moisture levels throughout the process.
Q. I have an area that is 20’x20’ and I need to rototill compost in the ground. How much do I need?
A. It’s easy! Use the handy coverage calculator built into our website.
Mulch
Q. How is WM EarthCare™ mulch made?
A. All of our WM EarthCare™ wood mulches are made from clean, 100% recycled, locally generated wood known as construction and demolition (C&D) debris. The C&D wood material is untreated and unpainted.
Incoming material is separated, sorted, and processed to remove metals, plastic, rubber and any treated wood (painted, pressure treated, engineered lumber—plywood, OSB, MDF). Clean wood is then sent to our mulch production facility in Fremont, CA.
The C&D wood is processed in a tub grinder to produce raw wood mulch. The raw wood mulch is then processed through a mechanical screen that produces finished mulch with an average size of 2″ or less known as “2-inch minus.”
Wood fines, 3/8 inch and smaller, separated in screening process are stockpiled for use as a mulch or soil conditioner.
Wood mulch and fines are available in a variety of colors. (See our mulch color chooser.) We also produce redwood mulch and redwood fines from recycled redwood fencing.
Q. How do you control for metals and other contaminants?
A. Metal, plastic, glass, rubber, and other non-wood materials are separated and sorted at our Materials Recovery Facility in Alameda County.
Non-wood materials are redirected for recycling separately.
Q. Can I earn LEED, Green Build, or Bay-Friendly points using WM EarthCare™ mulch?
A. Yes! Your use of WM EarthCare™ landscape materials can earn LEED, Green Build, and Bay-Friendly points for your project. Consult with your local LEED, Green Build, or Bay-Friendly landscape partner for details.
Q. What is used to color the mulch and is it safe?
A. WM EarthCare™ wood mulches are colored with safe and environmentally-friendly Amerimulch-Heartland Colorants.
The colorants are colorfast and safe for use around animals and children. The colorants used to produce our colored mulches are made from natural yellow iron oxide, red iron oxide, and charcoal (carbon) suspended in a water-based aqueous solution.
Additional information about our mulch colorants, including MSDS, can be found by visiting: http://amerimulch.com/mulch-colorant.php.
Q. Is there a mulch color that is better for my plants?
A. Research has shown that the microclimate around a crop plant can be influenced by mulch color. Black mulch has been shown to increase soil temperatures by 5°F in spring compared to soils without black mulch. Black mulch has also been shown to reduce weed growth. Red, yellow, blue, gray, and orange mulch have each been shown to have distinct spectral reflectivity characteristics that can influence plant growth. Yellow and gold mulch is attractive to pollinating insects, while blue mulch repels some insects. Red mulch stimulates tomato and bell pepper growth.
To learn more about the influence of mulches on vegetable growth see the University of California, Division of Agriculture and Natural Resources publication 8129 entitled: Mulches in California Vegetable Crop Production.
To see how one of WM EarthCare’s mulch colors might look in a typical application, check out our mulch color chooser.
Q. How much mulch should I use in my planting beds?
A. Apply 2–4″ of mulch over the entire planting area taking care to taper mulch away from the base of each plant. Avoid creating a mulch volcano around your plants!
Q. If I use more mulch, will it improve the soil’s water retention?
A. Applying mulch following the recommendation rate will improve moisture retention by 20%. In some cases, moisture retention is improved by 4 to 5 times. This is especially true when compost is used. Mulch should not be applied in excess of the recommended rate. Excess mulch can become a haven for rodents and other pests.
Q. How quickly does mulch deteriorate? Do I need to replace it often?
A. The smaller the mulch, the quicker it will decompose. Small, compact size, mulch materials can decompose within 6-12 months depending on moisture and temperature. Larger sized mulches tend to persist in the landscape for a longer period of 3-5 years. To keep your mulch looking fresh, it’s best to annually lightly top-dress (1″) your existing mulch.
Q. Is mulch good for all plants, shrubs and trees?
A. Yes! Applying mulch in your landscape is the single best practice that you can to do improve the quality of your soil TODAY!
Q. What’s the best time of year to apply mulch?
A. The best time to apply mulch is in the fall, at the conclusion of the growing season, and in spring after the soil begins to warm.
Q. Do you have information that tells me how Muir Woods Brown mulch is made?
A. Each WM EarthCare™ mulch follows the same process from clean construction and demolition wood recovery and sorting to grinding and screening. Based on customer preference, we color the mulch with a natural, water-based dye provided by Amerimulch (http://amerimulch.com/mulch-colorant.php). The colorant is safe for use around animals and children. It will is color fast and will retain its color for at least one year.
Q. How long will the color last?
A. The colorants we use will remain colorfast without fading for at least one year. Colorant is provided by Amerimulch (http://amerimulch.com/mulch-colorant.php).
To see how one of WM EarthCare’s mulch colors might look in a typical application, check out our mulch color chooser.
Q. What are the recommended applications for Mulch Fines?
A. Our WM EarthCare™ Treasure Island Fines have a number of uses. They can be applied directly in the landscape as mulch (ground cover) at a depth of 1–2″. The particle size of the Treasure Island Fines will hasten their decomposition. Treasure Island Fines also make an excellent soil conditioner— especially in fine, clay-textured soils prone to compaction, poor aeration and drainage. Treasure Island Fines can also be used at wet sites where heavy equipment use may result in rutting and erosion. Our fines prevent compaction while also working like a sponge, absorbing excess moisture.
Q. What is the minimum quantity for a custom color or screen size?
A. 50 cubic yards. To learn more, please contact a WM EarthCare Specialist at (510) 692-0613 or EMAIL US for more information.
