Question
what causes light brown discoloration on plant leafs starting at
tips of leaves? it gradually spreads to most of leaf.
       thank you bob robinson  nanaboo222@verizon .net

Answer
Bob,

Phlox is not a houseplant and if you are keeping it in the house that is the problem, it is not getting enough light and not getting the temperature drops at night and the breezes that it needs. It should be outdoors in the ground or at least in a hanging basket.

If it is outdoors that would indicate either too much or too little water. There are 2 knds of phlox, an upright variety and a creeping variety. If you have more questions let me know which kind you have.  Good luck.

Darlene