I have one of your coffee plants (Coffee Arabica), i just wondered if you could tell me why it was going brown around the edges of the leaves, even on the new ones, I have been giving it water, may be it needs some plant food or a bigger pot.
Where have you got your coffee plant, inside or out? If it is outside the cold / frost could be affecting it. Move to a warmer position. Ideal as a house plant.
Do not over water especially through winter, let the soil dry out and then water. Do not feed until spring as the plant is not growing at this time of the year.
If the plant has outgrown its pot, pot up in early spring ready for its spring growth.