Question
I have a philodendron that was an off-shoot of a plant I won for my mother in a cake walk 35 years ago.  The plant usually does very well, but every six weeks or so, I find a disease has infected several leaves.

The leaves almost look chewed (leading me to suspect my cat at first).  Left alone, the "chewed" spots grow, eating the whole leaf up. This happens VERY fast. When I've caught it early, I've cut the infected part of the leaf off, and it survives fine (just shaped funny forever).

I'll think the problem is licked for a while, and I'll go in to water it and find three more leaves with the problem.  Sometimes there is too much rot, and I have to remove the leaf.

Fortunately, it has enough leaves (and now, scissored leaves) that it continues to grow.  But can I fix this?  And what is it?

Answer
Hi James  This is what I found for you as I am not an expert on  indoor plants.    Most Philodendrons are native to the jungles of tropical America, and as such, prefer the medium light intensity they would have on the jungle floor. They will tolerate low light, but if there is too little light, the new leaves will develop smaller, and farther apart on the stem. On the other hand, direct sunlight will burn the foliage, and stunt the growth of the plant.
Keep the soil evenly moist, but allow it to dry out between waterings. Keep them slightly drier during the winter months, when the growth slows. Over watering will cause the leaves to turn yellow. Under watering will cause the leaves to turn brown and fall off. Feed your Philodendron in the spring and again in mid summer with a liquid house plant fertilizer.
The ideal temperature range is between 75 and 85 degrees F. during the day and in the 60's at night. They will survive for a short time in temperatures as low as 36 degrees F.
Philodendrons will tolerate the level of humidity found in most homes, but high humidity promotes lush growth and shiny foliage, so it is a good idea to mist the plant regularly. Wash the leaves regularly to prevent the pores from becoming plugged with dust.