Tree Preservation Orders (TPOs) Find a TPO, TPO criteria and development, submit a request to protect a tree, tree works on TPOs. Tree works How to report a problem, including dangerous trees, trees in public parks and green spaces, trees on private land, tree pests and diseases. Trees in conservation areas Tree management in conservation areas. Hedges Planting, managing and removing hedges and hedgerows, high hedges and overhanging branches.