Manual › Your garden
Rainwater and compost
Keep track of your rain barrel (with the rain added up) and your compost bin: when to turn it, when it is ready, what can go in.
How full is your rain barrel after yesterday’s shower? And when does the compost heap need turning again? In a garden or vegetable garden you keep track of it in the Rainwater and compost section. It is not there for indoor plants.
Adding a rain barrel
- Choose + Rain barrel in the Rainwater and compost section.
- Give it a name (e.g. Barrel by the shed) and its capacity in litres.
- Enter the area of the roof draining into it: length × width of the part of the roof that drains into that downpipe, measured from above. A garden shed is often 6 to 10 m², half a terraced house 30 to 40 m².
- Choose the roof type and how full the barrel is now, then Save.
It also works without a roof area, but then we do not add the rain.
How full is the barrel?
Next to the barrel you see how many litres (roughly) are in it. We take the last level you entered and add the rain that fell on your garden since then (the weather from Open-Meteo), until the barrel is full:
- 1 mm of rain on 1 m² of roof is 1 litre;
- not all of it reaches the barrel: about 90 % from a pitched roof, 70 % from a flat roof, 30 % from a green roof.
Used some water? After Now:, tap Empty, ¼, ½, ¾ or Full. That keeps the estimate right. We know the rain of the past month; if you entered the level longer ago, it says so.
You also see:
- how many watering cans (of 10 litres) it fills;
- whether the barrel will overflow with the rain expected this week. Use some water now, or lead the overflow to a border or a second barrel;
- whether little rain is on the way while the barrel is nearly empty;
- after how many mm of rain an empty barrel is full, and how many litres the roof collects in an average year (about 800 mm of rain in Flanders).
Tip
Does your barrel overflow with every shower? Then it is too small for your roof. A second barrel on the overflow, or a bigger one, collects more.
Adding a compost bin
- Choose + Compost bin.
- Choose the type: a compost heap or bay, a closed compost bin, a wormery or a bokashi bucket.
- Enter the day the batch started, and optionally when you last turned it. Choose Save.
Next to the bin you see how old the batch is, roughly when it will be ready, and a tip for that type:
| Type | Ready after | Care |
|---|---|---|
| Compost heap or bay | 6 to 12 months | turn every six weeks |
| Closed compost bin | 6 to 9 months | aerate every four weeks |
| Wormery | 3 to 6 months | feed in small portions |
| Bokashi bucket | 3 to 5 weeks | drain the liquid, then dig in |
Ripe compost is dark and crumbly and smells like forest soil.
Turning and harvesting
Turning a heap or aerating a bin shows up by itself in To do in your garden, in Today on the home page, in the reminders and in your calendar. Tap Turned (or Aerated), with a note and photos if you like: it goes in the log and the next time moves on.
Used the compost? Tap Harvested: it goes in the log and the bin starts a new batch.
What can go in?
Open What can go in the compost? below your bins. In short:
- Green (wet): fruit and vegetable peelings and scraps, coffee grounds, tea leaves, thin layers of grass clippings, spent flowers.
- Brown (dry): dry leaves, shredded prunings, straw, cardboard and egg boxes torn up.
- Keep out: meat, fish, dairy and cooked food (a bokashi bucket does take these), diseased plants, weeds with seeds or creeping roots, cat litter and coal ash.
Alternate green and brown, roughly equal amounts of each. Smelly or soggy: add more brown. Too dry and nothing happens: add more green or a splash of water.
Who can do what?
Anyone who sees the garden also sees the barrels and bins. Anyone who can work in the garden (including the participants of a community garden) enters the level and turns or harvests the compost. The owner and those who can edit add, change or delete barrels and bins.
Updated on 2026-10-05