Wide wicking beds at a school

There are various examples of wicking beds, and we have found the following approach to be the most successful method! 

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.