This northwest facing bank planting includes Cornus stolonifera ‘Isanti’ at the top, Perovskia atriplicifolia is the lighter grey middle band, with Cornus s. ‘Kelseyii’ below it followed by Helictotrichon sempervirens. This have differing water preferences. The bed is all on one irrigation station so will water equally. The Blue Oat Grass at the bottom of the bank will be the wettest due to surface runoff and ‘needs’ the least amount of water, in fact it is subject to rot with routine irrigation.