Humanure compost may go on a food garden only when its heat record shows 55°C or more for at least 3 consecutive days and it has aged at least one full year; even then, apply it first to fruit trees and perennial crops where it never touches the edible part, and work it into soil at least 3 months before planting root vegetables or leafy greens. If the heat record or the age is missing, treat the compost as contaminated and use it only on non-food plants.
Part of Composting Toilet Systems
Safe application is the set of rules that decide which crops may receive finished humanure compost, when, and how. The compost is a soil amendment made from human waste, so what is eaten and how it touches the soil matters as much as how long the compost aged.
Two Questions Decide What The Compost May Touch
- Is there a heat record? A log showing 55°C or more for 3 consecutive days at the core and the coolest point (Monitoring Temperature & Progress).
- How old is it? Counted from the day the bin or chamber was closed to new waste.
| Heat record | Age | Use |
|---|---|---|
| Yes | One full year or more | Fruit trees and perennial crops first; then root vegetables and leafy greens, applied at least 3 months before planting (parent page) |
| No, or not at the coolest point | Any age | Contaminated: non-food plants only, such as ornamentals, hedges and timber |
| Yes | Under one year | Not yet: keep sealed and wait |
Where The Wiki Disagrees, Use The Stricter Figure
The parent page allows one year of ageing and a 3-month gap before planting. Composting Toilet gives 6-12 months of confirmed heat for fruit trees and ornamentals, 12-24 months for root and above-ground vegetables, and 24 months or more for leafy greens and any garden use, and asks for 24 months minimum if heat was not confirmed. These are not the same rule. For crops eaten raw, or that touch the soil, use the longer interval and the heat record. Roundworm eggs are invisible, and an error in this table goes straight into someone’s meal.
Applying It
- Spread as a soil amendment, not a surface mulch. Work it into the top 15-30 cm of soil and cover with clean soil or mulch.
- Not before rain. Runoff carries it.
- Not on slopes that drain to a well, spring or stream, and keep it out of ditches. Source Protection puts compost and manure heaps within 30 m of a source as a high risk.
- Fruit trees first. The compost is spread under the canopy; harvest fruit from the tree, not from the ground, and wash everything.
- Never put it directly on a growing leafy crop or leave it on the surface among crops.
- Wash all produce, whatever fertiliser was used, as the parent page says. Peeling and cooking cut the risk further for roots and leaves.
Worked Example: A Planting Timeline
- A bin is closed on 1 January of year 0, with a recorded heat count of 3 days.
- On 1 January of year 1 it has aged a full year. Spread it under fruit trees that month.
- To plant carrots on that bed, compost goes in at least 3 months before sowing, so no earlier than a 1 April sowing. Under the first-month page’s longer rule, root vegetables wait until 12-24 months after closing, so I would not plant carrots in this bed before year 2.
- A bin with no heat record, closed on the same date, is treated as contaminated for any age: it goes to ornamentals and timber plantings only.
Common Mistakes
- Applying “it looks like soil” compost to the vegetable bed. Looks prove nothing.
- Mixing a new batch into an old one and treating the mix as old.
- Using the same fork and wheelbarrow for compost and for harvest.
- Applying to a bed that drains into the water supply.
Safety
Untreated or unverified humanure compost can transmit cholera, typhoid, hepatitis A and roundworm
Apply it only under the rules above. Wear gloves, wash hands with soap or ash and water afterwards, keep children away from beds being amended, and keep the tools separate. If you cannot show both the heat record and the age, do not put it near food.
What’s Next
- Learn next: Maintenance Schedules — keep the dates that this page depends on
- Combine with: Compost Maturity — finishing and checking ordinary compost