What Happens to the Soil After Human Composting?

The end product of human composting is soil, and that raises practical and emotional questions: What exactly is in it? How much is there? Can we plant a garden with it? This guide summarizes what published sources say. Rules vary by state, so we name the state each statement comes from.

Dated October 7, 2026. If human composting isn’t legal where you live, see where it’s legal.

What is in the soil?

Reports on the first facilities describe the following:

• Mostly composted plant material and remains. The body is composted with materials such as wood chips, alfalfa, and straw, so the result is a soil-like material. After the initial process, workers remove metals and plastics that were in the body, according to NBC News
• Bone. In a 2018 Washington State University pilot, each body produced 1.5 to 2 cubic yards of soil-like material that still contained bones, and the lead scientist said commercial processes would likely process the bones more thoroughly
• Not identifiable as a person. The pilot’s sponsor, Recompose, says the final material was unrecognizable as human remains visually, chemically, and microbiologically; a provider guide says non-organic items such as surgical implants are removed before the soil is returned

How is it tested?

In Washington, according to the Seattle Times, state rules require the soil to be held at 131°F for 72 hours to destroy pathogens, and require the provider and a third party to test the soil for pathogens and heavy metals including arsenic, lead, and mercury. Wikipedia and a provider guide add that remains exceeding the limits may not be released into the environment or to the family. The state also reportedly bars the process for people with certain diseases such as tuberculosis and prion diseases.

We didn’t read other states’ testing rules, so ask the facility what testing it performs and what the results were.

How much soil is there?

Sources say about one cubic yard per person in commercial operations. The family may receive some or all of it.

What can families do with it?

Sources describe these options:

• Keep some, often in a container or planter, as one might keep cremated remains
• Plant a tree or garden for memorial purposes, such as a memorial planting
• Scatter it. A news report says placement is treated similarly to scattering cremated remains in many places: landowner permission is required, and local ordinances apply. See what to do if scattering isn’t permitted
• Leave it with the provider. Some providers place unclaimed soil on conservation land. For example, a provider’s executive said that in Washington it owns land where it uses uncollected soil to plant trees
• Donate it to conservation or reforestation projects, according to a provider guide

What does the law restrict?

This is where state laws differ, so read each carefully.

Colorado. Colorado’s 2021 law (SB 21-6), as reported by several sources, does not allow businesses to sell the soil, to combine the soil of multiple people without consent, or to use the soil to grow food for human consumption. A bill tracker’s summary says the same. Colorado is the state most often cited for these limits.

California. California’s law, signed in 2022 and taking effect in 2027, bans combining multiple people’s remains unless they are family. According to a 2022 report, unlike Colorado, California did not explicitly ban sale of the soil or its use to grow food for human consumption.

Washington. Washington requires testing and bars release of soil that exceeds limits, as described above. A provider guide says Washington’s soil must be lab-tested by a third party for metals and bacteria.

Maryland. A provider guide says Maryland’s 2024 law (HB 1168 / SB 1028) includes the no-sale and food-use limits and extends the food restriction to livestock. We did not verify this against the statute.

Other states. We did not research the remaining states. That same provider guide says two limits show up consistently in states that have legalized the method: the soil can’t be sold, and it can’t be used to grow food for people. Treat that as a general pattern, not a guarantee, and check your state.

Can I use it in a vegetable garden?

Where a state bars food use, as Colorado does, no. Even where the law doesn’t say so, the question isn’t only legal: consider whether you and your family would be comfortable, and ask the provider. A scientist quoted by a farm publication says compost improves water infiltration and root conditions, but that is a general statement about compost, not a recommendation about growing food.

What if the soil comes back to a state where the method isn’t legal?

We don’t know. If you’re bringing soil back to Texas, for example, after arranging composting in another state, we found no source on whether Texas places any limit on what you do with it. Ask the facility and a licensed funeral director before you plan.

Add this to your Final Day Plan: whether you want some of the soil returned or placed on conservation land, who will receive it, and what you’d like done with it.

This is general information, dated October 7, 2026, and not legal advice. State laws on the handling of soil from human composting vary and change; confirm with the facility and your state funeral board.