Trees are important in any outside space. Whether you have a sizable oak tree in the corner of your plot or a small Japanese maple in a pot on the patio, trees help to add structure, shade and privacy to gardens. Some trees, however, are considered invasive plants, spreading rapidly and outcompeting native species. These invasive trees, therefore, must be avoided at all costs.
As a former gardener, I have planted, grown and cared for many trees in gardens across the UK and Italy. I have seen firsthand the damage invasive trees can do to gardens big and small, such as the black locust tree, Robinia pseudoacacia. This tree can be a real nuisance, sending out suckers more than 50 feet away from the main trunk, and finding its way under structures and beneath the garden fence.
