The curry leaf tree is a mainstay or south indian cooking. Here in the US, it is a prized possession. In the bay area you can get them at the local indian grocery store and they are pretty darned expensive.
About 3 years back we spotted a small plant on sale in the Indian grocery store in San Diego and quickly grabbed it on ur way back. We were not in CA then and were renting. So the small plant went into a smallish pot and in our patio. It did not grow much but was in good shape overall.
A few months after we moved into our new home, we saw this. We were newbies and literally clueless about what we saw. But we went online, researched, and solicited help from our friendly garden center. Turns out these were scales
Guru carefully took out all the damaged leaves, and with a ear bud and rubbing alcohol took off all the scales from the branches. Gave it a nice application of Neem and a thorough watering every other day. In a couple of months we were excited to new growth coming up. We had heard the soothsayers say that they didnt see much hope in it recovering.....and weren't we glad
Fast forward another year and in winter I forgot to move the plant inside and let it deal with the first winter frost in the bay area. It looks weathered and bare, but there is new growth sprouting out. Hopefully it will do well and we can set it in the soil this summer. After that it gets a nice burlap coat every winter to keep it nice and toasty.