Hello, is it possible to manage root growth by keeping ficus tree short? Currently several ficus next to each other at around 25 feet tall have become a problem as roots are going into sewer and pool approximately 40 ft away each. If trees are trimmed to a hedge, will that stop the roots from growing? Don't want to remove completely because trees were planted on sloop and don't want to disturb soil (to avoid erosion). Thanks for your response.