Hi Lori,
You say an open porch' - they are not too near the ceiling, are they?, because sometimes there is virtually 'no air circulation', if this is the case. It could also be due to over watering, or both. Water in the mornings if you can, don't give them more water again in the evening, if they are wilting at this time just give them a spray, preferably with rain water.

Also make sure that you don't have any dying or dead leaves laying on the soil, because this can cause botrytis (fungus).

If you just had 'yellowing leaves' with out the brown spots on then it could be lack of magnesium, if this occurs give them a dose of horticultural epsom salts.

Kath:)