Question
I would like to plant 10 thuja occidentalis smaragd trees along my driveway. I am a little concerned about the root growth because my gas pipes are about 3 feet from left side of my driveway. What is the extent of thuja root growth? Do you think it will cause a problem with my gas pipes?
Thank You for Your help

Answer
You will not have any problems with the roots of this plant. The width at maturity is about 3-4 feet meaning the branches will extend about 2 feet from the trunk. The roots are more fibrous are not prone to cause any problems with lifting or pipes. Gas pipes are sealed so the only problem would be lifting of the pipes--which is not a problem with the fibrous roots. The root will extent out about 1 1/2 times the width so about 4-6 feet at a max. Nothing to worry about. The only problem could be if the plant was planted close to the driveway so when it grows the branches extent near the drive hitting the cars. I would plant them at least 3 feet from the driveway and you should not have a problem. Of course they could always be pruned back if this becomes a problem.