Eastern Red Cedars are an amazing tree and in it's natural habitat can live upwards of 500 years or more. As the tree grows taller, the lower branches may begin to die because of lack of sun. You can cut them off, trim them, but know that Cedar trees will not sprout new branches like deciduous trees will. Once the branch of a cedar tree is cut off it's gone for good, so prune wisely. As cedars grow taller and branches die out at the bottom of the tree, the cedar creates a canopy overhead that feels magical to stand below. A grouping of cedars create an even larger canopy, but it takes a long time. The female cedar produces the bluish-gray berries and the males make very tiny pinecones.

Congrats to all, who made it through in a contented manner, to this day after Christmas. Hope all found some, if even the smallest bit, of Joy and contentment through this holiday season. Interesting to read the understandable, frustrations so many have suffered with the 3 inch long hooked thorns found on so many of the thorn producing, hawthorn varieties and cultivars. The nursery owner I asked to find my friend's desired thornless variety hawthorn, told me that none of His suppliers distributed either the thornless, inermis 'Cruszam' cultivar or my desired 'Frans Fontaine' hornbeam trees. Fortuately the Femrite tree growers located in Oregon posted both those trees on their availablility list, which they had updated on December 19. My local nurseryman has indicated, that if all goes as planed, those trees should be arriving, in bareroot condition, this upcoming February. Reports, I have recently read, indicate that bareroot hawthorns are a little difficult to bud, so I am wondering if it's best, at the time of delivery, to let the nursery pot-up this bareroot hawthorn, and care for it untill its buds swell; before my friend and I try to plant the tree. Still, I wonder how long my friend will want to keep the tree, if its spring, week long, bloom display stinks as some reports I've seen indicate.

The terms aren't interchangeable. Hedges are often, but by no means exclusively, composed of shrubs rather than trees. But yes, lining them up, having one touch and grow into the next and keeping them trimmed at a consistent height makes them a hedge. You can also have an informal hedge which might just be a dense shrub border which is rarely trimmed. Disclaimer... My concept of a hedge is very much governed by my own country's usage.

If the same behavior is still in effect when they size up then your maple and oak are going to get whacked back also. If you do not want these to be spoiled you had better re-plant them (when dormant) well away from the edge of the property. And if they are as close to it as they look in your picture in time the root crown of the oak in particular will actually get big enough to start deforming the fence. Also I would try to use evergreen plants as much as possible to make an unwanted, constantly present view disappear. As mentioned trying to build a wall of plants as close as you can to the neighboring building is not the efficient way to do this. And the individual shapes of your arborvitae hedge plants actually results in them pointing at the building, instead of it being made less noticeable. In other words the hedge reads visually as "Look at this ^^^^".