It's chlorosis, probably caused by alkaline soil, which makes many micronutrients unavailable for plant uptake. It's not uncommon to see it around concrete or brickwork, but it can occur anywhere. Domestic water supplies tend to run around pH 8.5, which means that areas which don't receive much rainfall—such as foundation plantings under wide eaves—will tend to have this problem moreso than other areas of your property.
A soil test is the most correct way to proceed, but if it were me, I'd find an iron and micro-nutrient supplement and give it a shot. These sorts of products usually contain something to help bring the pH of the soil down as well, which will make the micro-nutrients more capable of being absorbed by plant roots.
E.B. Stone Sul Po Mag is a good one
http://www.ebstone.org/product...
I've seen fast response from GreenAll F.S.T.
http://www.ebstone.org/product...
