Question
how deep do swamp cedars and emerald cedar roots grow approximately? And also how far out do the roots grow,approx.?

Answer
They both have fibrous root systems and are usually no deeper than about 2 feet. The spread (width) is about 1 1/2 times the width of the foliage Exp. the limbs reach out about 4 feet from the trunk  so the roots will be out about 6 feet. I hope this is what you were asking.