Plant Doctor Archive

Choisya not so choice

Question PARTS of my Mexican orange blossom shrubs seem to be dying off. The leaves on some branches are going quite yellow and drooping, while other shoots seem perfectly fine. Any ideas?

Answer  IT’S probably caused by lemon tree borer, which can attack a wide range of trees and shrubs. It’s a native insect that got its common name because of the extensive damage it can cause to most varieties of citrus. Luckily, Mexican orange blossoms (Choisya ternata) often recover from attacks by lemon tree borer.

The best thing to do is prune out dying shoots as close to the ground as possible and destroy the prunings, either by burning, shredding in a mulcher or disposal at the organic refuse station. New growth should soon appear, which will eventually fill the gaps. If necessary, you can prune the whole plant back hard to within 10–15cm off the ground. It will grow away again in spring.

Weekend Gardener, Issue 152, 2004, Page 27