Succulent jade plants (Crassula ovata) can store water in their fleshy leaves and stems, and they need less water that many houseplants. While they will tolerate long periods with no water, they thrive if watered regularly, especially during the warmer months. While an under-watered jade plant may grow very slowly and lose its leaves, an over-watered one is vulnerable to rot, which can quickly kill the plant.
Water jade plants only when the top 1/2 inch of their soil is completely dry. Provide enough water to uniformly soak the soil, and allow all excess water to drain out of the container's drainage hole. Never let the whole of the soil dry out completely, as this can cause dwarfing, foliage spotting, leaf drop and death, according to Clemson University.
Water jade plants more frequently during their active growing months of the summer. If a jade plant is moved outdoors into the sun during the summer, its water requirements will increase. Reduce watering during the winter, aiming to keep the soil barely moist. Avoid getting water on the leaves, especially during the winter, when cold and damp can trigger rot and mould.
Water the jade plant more frequently if its leaves are wrinkled and its lower leaves are shrivelling and dropping. A healthy jade plant has plump, glossy leaves. Large plants often fill their pots with roots and require more frequent wateing than small, less established plants. Reduce watering if any of the plant's branches become soft or if its top leaves start to turn yellow or drop off. Never leave a jade plant standing in a dish of water. as this rapidly causes rot.
Repot jade plants into moist potting compost, and allow the soil to dry out before watering. Keep the soil of newly potted jade plants barely moist until new growth appears.