Major leaf fall is an indication of poor irrigation--transplant shock--or perhaps plants not suited to your climate.
I am not a soil expert. However I think the soil is fine--perhaps the CEC is a bit low.
However, I think that the pH is a bit too high. Perhaps this is resulting in poor solubility of the iron in the soil solution. Manganese and other metal nutrients, also. If soil moisture, drainage and temperature are satisfactory...you might try to apply a chelated iron and micronutrients spray to some of the shrubbery. Follow the directions carefully. The new growth and some of the old growth should look better.
Alternatively, go to a major soil test lab and arrange a "tissue test". You send them the green part of the plant and they bake it to ash and analyze the mineral content in a spectrophotometer like in Abbey's lab on NCIS. Costs 5 times as much.
And finally--there is a potential for some kind of chemical herbicide in the soil itself. Plant some tomatoes in it--inside of course--and compare with a known good soil.