5. Maintain. Using the long trailers, carefully wind the ivy around the topiary form. If needed, secure ivy to the form with cloth-covered wire. To maintain the topiary as the ivy grows, continue winding the trailers around the form. You may need to clip bushy growth to maintain the shape; however, the trimmed ivy will quickly root if you place it in water. (Use these starts to begin another topiary.)
6. To finish, lay live moss around the topiary base, concealing the soil, as well as the form's base. The moss provides a natural protective barrier for the plants, helping them retain moisture. Stick greening pins through the moss to help secure it; water. Continue to water the topiary frequently, and periodically feed the ivy with houseplant fertilizer to encourage growth. The ivy will fill the form within a month or two.