Hey, when you're working with a 50-foot space, the first thing to think about is the general spacing. The arborvitae plant is pretty full and dense, so if it's about 3 to 4 feet tall, you can expect it to fill up that 50-foot area nicely. So, you can do the math: 50 feet / 4 feet / arborvitae = 12.5 arborvitae. That means you'll need about 13 arborvitae to make your 50-foot yard look great!