Elephant Ear Leaves
We have elephant ears that we replant every year in full sun. We have about 4" of mulch around them but not right up against the plant. This year they were planted in late May because it had been so wet. We put just a little bit of miracle grow on them even though it probably wasn't needed. Last year was the first time I noticed some issues with the leaves. I don't see any bugs on them but when I get up the next morning there is some damage to 1-2 of the leaves. I am concerned what may be going on. Do you have any idea what it is from and what I can do?
The brown area on the third photo leaf looks like sunscald. This may be helpful: http://extension.umd.edu/hgic/plants/excess-light-sunburn-and-light-requirements-houseplants Sometimes a period of intense growth (also a long period of cloudy overcast weather) leads to a lot of tender growth. This tender growth can be less tolerant when suddenly the weather switches to full days of full and high temperatures.
The fading leaf tips is not a disease or insect. It, too, is an abiotic problem. It may be that the roots, though they like it moist, are getting too wet. Saturated soil can drown plants. Perhaps that spot doesn't drain well. We also had a period of relatively cool temperatures and lots of rain for the beginning of last summer. Be sure your plants aren't sitting in drenched soil all the time.
If you haven't been fertilizing, you may have a nutrient problem. Since they grow so fast, they are also heavy feeders. They can be fed each time you water and respond well to foliar high nitrogen fertilizers.