Originally Posted by kittysecrets4u

OVER FERTILIZATION - Causes leaf tips to appear yellow or burnt. To correct soil should be flushed with three gallons of water per one gallon of soil.

PHOSPHORUS (P) - Slow or stunted growth, red stems. Smaller leaves that are dark green. Lower leaves yellow and die. Add chemical fertilizer containing P. Affected leaves will not show recovery but new growth will appear normal.

Hope that helps.