Question
I have had an outdoor/indoor Boston fern for two years.  It usually loses a lot of the bottom fronds in the winter, but just within the last week, almost half of the plant, nearest the window, have become dark brown, oily and they have an odor.  Could this be a disease or is it something else entirely, like over watering or a draft?

Answer
Marge:

Thanks for your question. If the fronds nearest the window lok wet and have a sour odor then these may have developed a soft rot.  If the fronds were actually touching the window they may have been injured by poor air circulation in combination with heat from the sun and moisture that may have lent itself to the rot. If possible, avoid the leaves pressed up against the window and keep air circulating amongst the leaves.  These fronds may turn brown and crispy.  you can give it a haircut to remove these.  Just try to encourage dry leaves to avoid the problem.

Be sure to remember not to overwater your plant!  They use much less water inside than out.

Steve