Since the blueberries sulk on hard tap water, rainwater stopped being a nice idea and became a necessity. This summer I finally set it up properly.
The setup
The shed roof is about eight square metres. A simple diverter on the downpipe feeds a 200-litre butt, and an overflow hose links it to a second one of the same size. Both stand on concrete blocks so a watering can fits under the tap.
How much it collects
The rule of thumb works surprisingly well: one millimetre of rain on one square metre of roof gives about one litre. A 25 mm summer storm on eight square metres means roughly 200 litres — one full butt in an afternoon.
The dry spell
In the first half of August we had eighteen days without rain. The blueberries, the pots and the new plants under the pines used about 30 litres a day, so the 400 litres lasted almost two weeks. Close, but not enough.
Next steps
- A third butt on the house downpipe.
- Lids on everything — mosquitoes found the second butt within a week.
- Mulch, mulch, mulch. Needles on the blueberry bed cut watering noticeably.