I have strange winter weather, We get rain, hurricane type rain. Within 24 hrs we can go down to 0 - 20 below 0.
Even planting on a once gravel walk the not enough drainage the block of ice they were sitting in was certain death. If that did not kill them we are warming back up and so they are then sitting in ice cold water. The coir is immediate drainage. You know how you cannot keep those hanging basket moist. It turns out they are perfect for the Hercs.
They are not pond plants