Any Experience Shaping Emerald Green Cedar Hedge?

Question:We have a hedge of pyramidal Emerald Green Cedars (about 35 trees) which we planted 6 years ago and are now well rooted and thriving. While they have reached the minimum height I want them to be (there is no maximum), I would like them to fill in a bit faster between each other (at current rate I figure it will be another 3-5 years!). Before I go out and chop a few inches off the top with the hopes of accomplishing this, I thought I'd ask if anyone with experience has any warnings for me. I don't want to do anything that could kill them off!

Answers:
What a great question and one that shows your wish to help these beautiful plantings. Please look at the Library for a copy of Wyman's Garden Encly. or on the Internet for data on your shrubs under Wymans Garden Encly.
The first thing you should know is that this is a hybrid and I hope you planted them at least four foot (base to base) apart.
This is really an Arbovitae and is slow growing. The habit is to be a cone or pyramidal shape. Topping them will not make them spread any quicker.
You will find that the max in height is ten foot after about twenty years. These Arbovitae grow 1 foot horizontal the 1 foot in height. Consequently they are considered Pyramid in growth.
Topping the shub will do nothing to spur higher growth. In fact it will make the horizontal stronger in growth pattern.
While an Arbovitae in origin it shares the Cypress family in not wanting or accepting pruning. Remove the dead, the browned/wilted, but leave the plant alone with the shears.
In late fall (between Halloween and Thanksgiving) you can "shape" the plant with shears. Fertilize with a Granular basic Acidic Fert three weeks before you do this. Make sure the plant a covering of Sphagnum Moss (1") and Hardwood Mulch (2") after the pruning. Your shrubs are the type used to make shapes found in many parks!
Protect your investments with a Dormant/Superior Oil spray in both early Spring and August. I suggest an application of Sevin in June (Father's Day or 6 weeks after the Dormant) to protect from bagworm, tent catterpillars, and other diseases. Spray the entire plant from top to bottom with the Oil. Spray the entire plant and the ground under from the base to six foot away with the Sevin. The Dormant Oil will suffocate the existing disease and insects and is non-toxic. The Sevin, mild toxic, remains the leading remover of the bagworm and tent cats that infect your plants. Follow the Manuf Recs.
Hope it helps. At best you will have a healthy but full hedgerow in the furture. The height will probably not be more than 10' I am at gjgjobs@yahoo.com