Moisture can be a concern in a potted plant. The roots of the plant need water for nourishment so the soil in the pot should retain moisture the way it would if the plant were in the ground. Since well-draining soils are a must in pots, this gets tricky. You don't want to rot the roots with too much water sitting at the bottom but you want to ensure the plant is getting enough water at the same time. A mulch made of bark can help to retain moisture and nourish the plant when placed in a pot as well as look attractive. Bark mulch also helps conserve water, which is great for your pocketbook as well as the environment.
Fill the pot half way with a mix of compost and soil. The mix should be about half and half.
Place the plant in the pot and surround it with soil. Make sure the soil comes to the top of the plant's root system.
Lay a thin layer of bark on top of the soil, completely surrounding the plant. Bark breaks down slower than most mulches but will still eventually compost into the soil so be sure it is a good-quality bark.
Water as needed. Check the bark regularly. If it feels moist, do not water since the bark is still retaining moisture for the plant to use. Over-watering will kill the plant.