Answer: The off color foliage and the webbing are clues to follow up on. I suspect spider mites. These tiny little pests (about the size of a grain of pepper) feed on the fluids within the leaves and cause stippling (off color). The also leave little web like material on the undersides of the leaves and stems. They like hot, dry conditions such as those found towards the interiors of the plants. You can discourage them by routinely hosing off your plants to dislodge the pests. You can use homemade soap sprays or use a miticide (available in garden centers) to rid your plants of spider mites.
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