Question
Will the Thuza Green Giant have any long term problems from growing together being planted that close of 4-5 feet since it says they grow 10-12 feet wide ?
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The text above is a follow-up to ...

-----Question-----
I am planting 100 5 gallon 4' tall green giants for a privacy hedge on cleared land in full sun for a total length of about 600 to 1000'.  What would be the best spacing between plants for the long term growth but to have a completely filled in hedge for privacy ?
Thanks !!!
-----Answer-----
For a hedge or a screen the plants should be spaced 4-5' stem to stem. Make sure you dig the planting hole twice the size of the rootball and fill with a good top soil and mulch around the trees.

Answer
If you want a hedge the 4-5 feet is great. Over time you will have a continue green Hedge instead of individual trees. If you want the appearance of them looking like individual trees then you should plant them about 8-10 feet apart. The planting 4-5 feet apart will have no effect on the overall health of the trees--they will grow together nicely and make a hedge. This is the best way to block off a place --or you could stagger the trees in two rows about 8-10 feet apart and get the same hedge appearance but it will take almost. The hedge will be twice the width as a single row. If you have the room this maybe what you want to do.