Brachychiton populneus x rupestris

This tree should be watered deeply and regularly (when the top couple of inches of soil has dried). Usually this will mean every week or two during dry weather. A few years after the tree has been planted, once it's established, you can likely cut back to deep infrequent waterings. Use drippers, emitters a slow stream of water so that it doesn't run off; allow the water to trickle all the way down through the deepest layers of soil. Often a tree will tap into groundwater and need less watering or none at all, once established. However, if you want to increase the speed of growth, water more frequently in the warm season.

A great trick for watering street trees is to drill a half-inch hole on the bottom edge of a 5-gallon bucket, then set the bucket with the hole aligned next to the tree and fill the bucket with water. Fill once for a 1-5 gallon plant, fill twice for a 7-15 gallon plant, three times for 25g or larger plants.