It can be confusing when searching for information on how to build a wicking bed. The following approach has been thoroughly tested and found to be very successful.

NOTE: Put only soil in wicking beds; do not use rocks or a plastic liner above the 90mm pipe to ‘stop soil being washed into the pipe’. That does not happen as the water moves out from the pipe, not into it.  Excess rain seeps in, it does not flow in. Stones waste space that should be filled by soil and soil biology. Soil biology is what makes plants, and thus us, healthy.