3. Best small and shapely ornamental tree 'Japanese maple trees (Acer palmatum) are both visually appealing and manageable for a courtyard garden,' says Alex Betz. 'With their compact size and ...

Thuja trees require minimal pruning and moderate watering, thus thriving in small gardens and courtyards. Ddamulira notes, “Thuja is ideal for those who want privacy without a bulky tree.