Our rear property line is 75' long and backs up to the backyard of another home. I am working on building an area at the rear of the yard with a firepit, picnic table, etc...and would like some privacy. There are a number of mature trees on the property line, but for the most part it's wide open, so I'd like to plant a "privacy hedge" along the line to close our backyard in. Would forsythia be a good choice? I've read that some varieties will grow up to 8-10 feet tall and 8-10 feet in diameter, so I was hoping that if I planted to them about 7' apart along the line (set back about 4' to allow them room to grow) that they would grow into a nice dense hedge.
I want a natural looking privacy and sound barrier on my lot. I plan on planting a mix of some or all of these evergreens: English Laurel, Dwarf Waxmyrtle, Sarcococca, and Loropetalum. Forsythia can help with summer privacy. I may plant a few, but as accent pieces, not for privacy. I've heard you can break off a branch and throw it in the ground to start a new bush.