I've had a very wet, cold, overcast summer in our coastal zone 6 southcentral Alaska. We've had a lot of rain over the last three weeks with 17" this last weekend topping it off. I'm getting a lot of yellow veining on lower leaves, a few with small brown spots ringed in yellow. Could this be excess water and cool temperatures, because they look like textbook virused dahlias. The plants seem healthy and are putting on gorgeous blooms, but their leaves are yellow along the veins (only lower leaves).

Thanks - Clay