Brown leaf tips on palms may be caused by one or more of the following:
Dryness. If the palm is not getting enough water, or if the humidity is too low, the leaf tips will turn brown. Water more frequently and on a regular basis.
Salt. Salts from water accumulate in the soil over time. The salts may come from fertilizer dissolved in the water or from minerals in the water itself. Excess salts are taken up by the plant and deposited in the tips of the leaves, causing burning and browning. Prevent the salt buildup by leaching (flushing) the soil with distilled water periodically.
Chemicals. Some chemicals such as chloride and borate can accumulate in leaf tips and cause browning. If your water source has chloride or borate, use distilled or rainwater instead to water plants. You can trim the brown leaf tips to keep the plant more attractive. Avoid removing the entire frond before it turns completely brown. As long as the leaf has some green tissue, it's photosynthesizing and contributing to plant growth.