Question
I live in central Florida.  I have Hydrageas in the front of my home in pots in good potting soil, but hey seem to be getting brown spots on the leaves and the leaves are sometimes turning yellow or brown.  Is this from too much water or sun ?
Jean

Answer
Hi Jean,  Hydrangeas are susceptible to several fungal leaf spot diseases, the most likely candidate is Cercospora.  It's quite common in late summer and fall, usually more prevalent on stressed plants and after heavy rains, but seldom kills.  It just looks ugly.
Container plants tend to be more susceptible if they are crowded (which prevents good air movement), rootbound (the container is just too small) or if they are stressed from inconsistent watering.  The yellowing and dropping of foliage may also be attributed to watering problems.
A monthly fungicide application, begining in late May through September, should prevent this if it becomes a recurring problem.
Because we flush so much water through containers, remember to fertilize them often with a good quality fertilizer.  Stay away from cheap water soluble products that will cause chlorine build-up in your soil.  Chlorinated salts accumulate in the tips and margins of leaves and cause browning or streaking. Use timed release fertilizers or slow release products like fish emulsion.
Have a great gardening day!  Jim Crowder