· John Heider's Answer
· Michael-The Golden Threadleaf Falsecypress (Chamaecyparis pisifera 'Filifera Aurea')
can grow to 20' tall and 15' wide in time. They are slow growing and will most likely take 15 or 20 years to reach 10 or 12 feet. They are a relatively low maintenance shrub that need very little pruning other than removing any dieback if any each year. When pruning is necessary to control its size it is recommended to only trim back the new growth of the current season.
There are smaller varieties of the Golden cypress such as the Golden Mop Falsecypress that will grow to 6 feet at matruity and the Golden Hinoke cypress that will reach 10 feet. If you can exchange the plants for a smaller variety you may want to look and see what is available at your local nursery. From what I have seen and read, growing naturally it will most likely take ten years to reach a height of 7 to 10 feet. With some pruning each year you should be able to keep it at a size you desire for quit a few years.
I have noted a Gardenality article regarding pruning conifers you may be interested in. Just click on the link below to go directly to the article.http://www.gardenality.com/Articles/447/How-To-Info/Pruning/How-To-Prune-Coniferous-Evergreens/default.html
Hope this has helped with your decision. - John)