I like the look of the poplar tree but as it's roots are invasive can anyone come up with a different species that has similar appearances. It will be planted in a medium sized garden.
Hey Michelle, try a Chilean Willow - Salix chinesis Fastigiata - they have a similar shape and size but are not fully deciduous in warm climates, unlike poplars.
They grow very fast and need plenty of regular access to moisture.