A few options are too much water, not enough water, and a deficiency. So check the soil moisture by poking you finger into the soil, and maybe get some fertilizer. Do you do any fertilizer applications like manure in the fall? What's you weather been like? Cold? Hot? Wet? Dry?
Before I planted my garden. Put my homemade compost w/ chicken manure that I get from my chickens that's in my compost. I live in northern California. We've been having high 90's. But it's suppose to drop into low 70's change of rain. I have a water prob that every few days I check on it & it seems like every 2-3 days I'm watering it.
I have a water prob that I use it seems like it's every 2-3 days is my schedule of watering. When I planted my fall/winter garden I put my homemade compost w/ chicken manure after i clean out my chickens coop. We've been having high 90's but we are having couple of days of mid 70's. Then before I planted my summer garden I treated it again with more of my compost. I've also checked the ph & it's reading perfect.