It could be iron chlorosis. Try treating it with chelated iron.
Some good looking garden beds, guys. For mulch and weed control we use black landscape fabric to cover the garden except in the narrow planting rows. The fabric is then covered with wood chips which further holds moisture and keeps the fabric a little cooler. Much less weed control work. The fabric lasts about 3 years.
I used to rototill every spring but lately using the fabric I till when the fabric deteriorates. The wood chips get tilled into the soil. The decomposition of the wood chips pulls nitrogen from the soil so you should add a little more nitrogen to compensate.