The leaves on some of my potted milkweed have turned from a nice dark green to a hazy green. The monarchs are not laying eggs on these plants. I don't know if I am over watering some plants that may be causing this. I keep them in filtered sunlight. This is the first year this has happened. I live in Central Fl and our temps have been in the high 90's. I did not have this problem in the Spring.

Would appreciate any ideas on what may be causing this.

The weather has been pretty dry, so you might have some spider mites on the leaves. Check by running a leaf between your thumb and finger. If your fingers come away yellow or orange-y you have spider mites. Just spray the plants off thoroughly with the hose, being sure to get both tops and bottoms of the leaves. Do this every day for a few days, if it doesn't rain.

Spider mites do love hot, dry weather but are washed away if it rains or you spray your plants regularly. They make the leaves look hazy and light green by sucking out the plant juices from the leaf surface. Even if the damaged leaves die, the plants will recover, just like they do when the caterpillars eat them.