I take care of a commercial property that I started maintaining when the landscape was first installed a year ago. 92 of the plants looked bad when first installed and progressively went down hill. When they died the store had me replace them. The new ones are still alive but have started to yellow in alot of areas. The same thing happened to a different group of plants in different bed and they were replaced. A few weeks later they are beginning to yellow. Another group of plants are doing the same thing and gradually losing all of there leaves until death(stem is brittle with no moisture but plenty of irrigation). This was the first time I had a soil sample done for any property. I brought the sample to a chemical dealer. She suggested this copper/magnesium spray to green them up quickly. Two months later that did nothing.... The soil sample suggested a generic fertilizer mix of 8-8-8 or 13-13-13. I applied the 8-8-8 and noticed some greening in the healthy plants but nothing in the yellowed plants. I am in desperate need of a quick fix. I do not have time to try something only to find it didnt work. The only chemical dealer around here cant really give me a straight answer on what to do. The levels are these values: PH 6.97, Phosphorus 27.17, Potassium 111.33,Calcium 1,360, magnesium 166.56, sodium 111.33, sulfer 28.23, copper 1.85, zinc 2.93. Irrigation has been set at 3 times per week for 15 minutes for the past few months . Prior to that it was 5 days a week at 10 minutes but noticed some areas holding to much water after light digging. Any suggestion is highly appreciated!