Question
I have 20 emerald green trees which are 10 years old. I live in Baltimore, MD.  I have been watering them once every 1-2 weeks when it does not rain. They look good on the outside but the inside of the trees is brown and dead-looking. All of the green growth is on the outside tips of the branches. Two of them have the brown and dead spots showing from the outside. There are a lot of dead bunches of needles bundled up throughout the insides. What can I do to make them healthier? I usually fertilize them in spring and fall but I missed this spring. Is there something I can do now?
One other question, I am looking to plant some sort of shrubs or bushes around the outskirts of my property for more privacy (instead of a fence) but want something that does not require a lot of trimming and something that grows around 4-5 feet tall. Any suggestions?  

Answer
Carolyn,
Arborvitae, like all evergreens, usually will kill off their inner growth when they establish their newer growth. This is the normal growth pattern. The thing that concerns me is the description that there are dead bunches of needles. If the bunches look like bags- then you may have an infestation of Bagworm. These caterpillars live in the bags and feed on the foliage at night. If it is not bagworm, then they may just need more water through these hot times. Make sure that the soil stays moist to a depth of 5 inches each week.
As for border hedges, Cornus alba 'Ivory Halo' or Ivory Halo Dogwood, grows 5-6 feet tall and has varigated green with cream colored edges. Weigela is also a noce choice that would grow around 4-5 feet. Spirea nipponica grows frm 3-5 feet and has nice white flowers in the spring.
As for evergreens, Taxus media 'densiformis', 'everlow' or 'greenwave'. These yews grow between 3 and 5 feet tall and require biannual pruning. Buxus microphylla japonica, or Green Beauty Boxwood, will grow to between 4 and 5 feet. I hope I gave you enough choices
I would recommend using several different plants in groups around the border. This will break up the monotony of using just one type and add interest to the landscape.