|I am looking to line my backyard to have a natual screen that is about 100 feet wide. I didn't know if I should go the direction of Junipers or plants like Fosythias. I wasn't sure what would be better in my area or zone. I would like the plant to be at least eight feet in height and not to deep in depth.|
|Your zip code places you in zone 6A or the colder part of zone 6. If the site is exposed and windy, it might actually be as cold as zone 5. So you will need to look at shrubs rated winter hardy into zone 5 to be on the conservative side.
Either junipers or forsythia might be a good choice. Both require full sun and well drained soil and are generally low maintenance plants once established. The junipers need to be spaced far enough apart that they will have good air circulation and sun on all sides when they reach their full mature size. They also grow fairly slowly, as do most quality evergreens. Another evergreen often used for hedging is the arborvitae. This will tolerate a somewhat moister soil than junipers and there are many nice columnar cultivars to choose from.
The forsythias are much faster growing (as are many deciduous shrubs), but can look unkempt in a formal setting. They also have a bold spring bloom color, then look fairly nondescript the rest of the year. These tend to grow at least as wide as they are tall, so the width may be a problem for you -- most would be eight feet across or more. Pruning to keep them narrow ruins the natural shape of the plant and can interfere with blooming; a sheared look is not suitable with this plant.
Your local county extension and/or professional nursery staff should have additional suggestions based on a more detailed understanding of the growing conditions (soil type, wind exposure, space available, etc) and your overall design goals. Good luck with your project!