Question
WHY ARE THE LEAVES ON MY HOUSE PLANTS TURNING YELLOW AND BROWN.   I WATER THEM ONCE A WEEK.  WHAT AM I DOING WRONG?

Answer
probably watering improperly and/or not fertilizing on a regular basis. improper watering is uusually the #1 reason for leaf yellowing.  water by weight. put a saucer under the pot. water and let the plant sit in the excess water for 5-10 minutes.  after that time pour off any excess water in the saucer.  pick up the pot.  it should feel heavy.  don't water again until it feels considerably lighter in weight.  outdoors check the plant everyday. indoors check it every 3-10 days.  watering frequency depends on many factors(sun exposure, type of plant, wind, day temps, etc.).
after so many years yellowing leaves can be a sign that the plant has not been fertilized on a regular basis.  adding new soil will help alliviate this problem quickly.  indoors you need to add fertilize on a weekly to monthly basis during the growing season.

good luck.  
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