Q.Rainbow eucalyptus tree is sick
I have a rainbow eucalyptus. It’s been planted for about a year and grew quite a bit. Perhaps 10 feet already. Now, however, on one side the branches starting at the bottom going up around 5 feet have all died. No leaves, dry sticks breaking off, no interior green signs of life. The rest of the branches are still green and producing leaf shoots. Many leaves are drying (and not in a typical dry from fall kind of way) and crumbling despite the new shoots. What should I do?! I love my ‘Randal’ tree and want it to be happy, please help!

This tree needs a warm and humid environment to grow.
Zone 10 or warmer and the tree need regular watering, it must never dry out.
Most likely the die off is due to environmental issues.
Here is a link to refresh you on the care requirements.
https://www.gardeningknowhow.com/ornamental/trees/eucalyptus/rainbow-eucalyptus-tree.htm