Place your silver cypress bonsai into an 8- to 10-inch unglazed planting pot that has a large drainage hole. Fill the pot with coarse, fast-draining soil and pack it evenly around the tree.
Check the tree's moisture level daily and water it until the top of the soil is dry. During the fall and winter months, the plant will require less frequent watering. Create a bonsai tree fertilizer by diluting regular houseplant fertilizer with water so that it's half the strength. Fertilize the tree regularly during the spring and summer months, which are times of rapid growth; you don't need to fertilize the tree at all during the winter.
Place your bonsai tree in an area of your yard that receives full sun. Prune the bonsai tree by either pinching the foliage off with your fingers or using a concave plant cutter. Prune the tree's foliage at the same time that you prune its roots to ensure an equal balance throughout the plant.
Re-pot the bonsai tree every two to three years to encourage growth.