Wicking beds
A raised bed with a reservoir underneath. Watering drops to a fill every week or two.
What it is
A sealed raised bed with a gravel or pipe reservoir in the bottom, a fill tube, and an overflow at the top of the reservoir. Water wicks upward through the soil column; the plants drink from below.
The numbers
- In dry country, watering frequency drops from daily to roughly every 7–14 days.
- Reservoir depth of about 8–12 inches under 12–18 inches of soil is the common working range — much deeper soil and the wick doesn't reach the top.
- Overflow is mandatory. A sealed bed with no overflow is a bucket, and the roots drown.
Why it's here
It removes the daily failure mode. On a deck, in a drought, or for anybody who travels, the question stops being *did somebody water* and becomes *is the reservoir full*, which is a question you can answer once a week or let a float valve answer forever.
The automation angle
A float valve from a tank makes it genuinely zero-touch. A level sensor in the reservoir gives you the draw rate — a surprisingly good read on how hard the plants are working, and an early warning of a leak in the liner.
The catch
Salts accumulate. A bed that only ever receives water from below has no way to flush, and in arid country with hard water you'll see the crust within a season or two. Flush it from the top once or twice a year — a good long soaking rain does it for free if you get them.