They were transplanted about 2 weeks ago. The starts looked very healthy, but a few days ago, some of them started developing brownish/reddish (rust, really) colored spots on their leaves and the tips of the leaves then began to look burned.

We experienced a bit of cool weather right after I planted them, with highs in the mid-50's to mid-60's and low 50's at night. It warmed up a few days ago, but the plants are not looking any better. I have been watering them every day or two, depending on the weather, while they are still fairly new transplants. They are in raised, framed garden beds, so the soil drains very good. I added a bit of composted chicken manure, ground bone meal, and ground oyster shells to the beds before planting.

Any clues on what's wrong? Did they get too much of something (like nitrogen)? Am I watering them too much or too little? Was it the cold temps?

Any help would be greatly appreciated. I'm new to gardening, and I have not been able to find anything in my many web searches! THANKS!