It started months ago, when my 3 yr old AquaSoil became exhausted. Last week I removed everything and replanted the healthiest looking wisteria stems in new Eco-Complete. Have also maintained my dosing routine. At present P=1.0-1.5, N=5-6, and I add K and Flourish as well. However, the wisteria is still having the same problem: older leaves turn dark and wilted, and even new growth is very slow. When the AquaSoil was new, it seemed to grow 1/2" a day. What am I missing? Thanks.