Combine a complete soluble houseplant fertilizer, such as a 10-10-10 or 12-12-12 blend, with water. Use the amount of fertilizer and water recommended on the label for interior foliage plants, as the fertilizer amount differs between manufacturers.
Water the jade plant with the fertilizer solution in April, when the plant starts new spring growth. Apply the fertilizer every three months through October, for a total of three yearly applications.
Water with plain water, once weekly, between the fertilizer applications. Water from the top of the pot so the moisture drains from the bottom, as this allows the water to flush out any excess fertilizer salts in the soil. Empty the tray beneath the pot after watering.
Stop all fertilizer applications after October. Avoid fertilization during the winter semi-dormancy period of the plant, but continue to water the jade with plain water.