I was planning to prune the emerald green hedges on my driveway. I don’t know what they are exactly but looking on the internet, I think these are Emerald green (thuja). Although on the outside they look green, on the inside it has dead leaves. The green leaves are on the tip of the branches and are about 2-3 inches. What are some of the things I should do to take care of these? Can I prune them now about an inch? Should I clear all the dry leaves?
I have Emeralds myself, but these look a little too rounded on top to be Emeralds, unless someone topped them awhile ago. As to your questions:
You should be able to remove the dead leaves (and usually more than a few spiders) simply by roughly running your hands through the interior. The dead stuff usually just falls out.
It is okay to prune now. I'd cut the dead exterior leaves back to where you see living tissue. This is what nursery workers do to Thuja every May in Wisconsin.
The only care Thujas need is watering when in a drought (they like at least 1" of water a week if you're not getting any rain) and elimination/prevention of competition. Any other plants so close to the Thuja that they touch it will kill the areas that they're touching, so make sure that doesn't happen. It doesn't look like you're in deer country because your Thujas don't look like lollipops - Thujas don't live long once deer start feeding on them.
Some people protect their arbor vitae from snow-load and winter sun scald ("burning") by wrapping them in burlap, but I don't. If you live in a cold-weather area, you can avoid burning by ensuring that your Thuja are well-watered going into winter and by watering them if there's a warm snap that melts the ice in the ground. More evergreens die from burning coming out of winter than from the winter, due to lack of moisture in the ground for them. I avoid snow-load by pruning the shrubs to a single leader.
Oh yeah - don't use ANY sidewalk or driveway salt anywhere near them. Thuja are definitely NOT salt tolerant.
One warning - I was once pruning sixteen 8-9 foot high Thuja that were in a block of four 20 gallon pots by four 20 gallon pots. The Thuja were blooming and as I worked inside that block of shrubs I kept disturbing the pollen, to the point where it was painting me tan. I then started having breathing difficulties, most likely because I'm allergic to Thuja and didn't know it. I had to leave the area ASAP and stay out of it in order to keep breathing. Additionally, some people are bothered by prolonged exposure to the leaves on their skin.
