Answer: Since elms do have quite shallow roots, I wouldn't want to take a chance on disturbing them by planting underneath. If you brought in soil for your new bed, the elm roots would suffer from the soil compaction and reduced oxygen supply caused by the new plantings on top. If your tree became stressed, it would also then be more susceptible to insects and disease. I've tried to plant under shallow-rooted trees and have given up because neither the tree nor the plants underneath were happy with the situation. <br><br>If you want to dress up the area under the tree, you could spread some cocoa hull mulch (which also smells wonderful).
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