Brown-edged leaves on a plant often indicate that salts have built up in the plant's soil and given it "saltburn." It is essential to flush the excess salts out of the soil before they kill your plant. This process is often referred to as flushing or leeching. This can be done with plain water, but adding vinegar to the process is more effective because vinegar helps neutralize the salts
Move the plant outside or place it into a sink. If the plant is too large to be moved, you will need a turkey baster and a bucket to remove the excess water from the plant's saucer.
Check the top layer of the plant's soil. If you notice a white crust of salt, remove the top layer of soil before you begin. Do not remove more than 1/4 inch of soil.
Estimate how much water the plant's pot holds. To flush the soil, you will need to run about twice that amount through the soil. For example, if the pot holds 2 quarts of water, you should run 4 quarts of water through it.
Pour the water onto the plant and allow it to run through it. Repeat a second time.
Repeat Step 4, but add 1/2 tsp. of vinegar per quart of water.
Every other week, use the vinegar and water solution (1/2 tsp. of vinegar per quart of water) to water your plants.