Colette writes: “I cleaned up my New Zealand Flax yesterday and discovered lot of white powdery ‘stuff.’ Any ideas or suggestions on helping this guy heal?!”
Here we see a very a common occurrence in San Diego landscapes. Last time we talked about “powdery” mildew, but this is not powdery mildew.
How do I know this. Well, it is impossible to correctly diagnose a plant without actually seeing the plant, and of course, positively identifying the plant. Luckily Colette is pretty sharp, and she sent me a photo.
Furthermore, even without seeing the photo, I know that New Zealand Flax is one of those plants that simply does not get powdery mildew. There is one bug, however, that definitely loves New Zealand Flax: mealybugs!
Mealybugs are sucking insects (like aphids, scale, and whiteflies). They look like little white fuzzy bugs, and when they congregate in mass it looks like powdery, fuzzy, cottony stuff.
Mealybugs can be difficult to control for two reasons. First, their fuzz actually repels liquid spray a bit. Not thoroughly spraying/treating a plant won’t work. Second, mealybugs hide in the deepest folds of the leaves, on plants stakes/ties, on the plant tag, and on the edge of the pot.
The Solution = persistent and consistent.
There are many synthetic controls for mealybugs – caution: do not buy a bug control with fertilizer in it (like some systemic controls for roses). New Zealand Flax doesn’t like lots of fertilizing. If you find a control in which the active ingredient is Imidacloprid, I would encourage you first to google that word and create and informed decision about your purchase. Always read the entire instruction label before using, AND follow the instructions.
For an organic control, here again it’s Neem Oil to the rescue = an excellent control for mealy bugs. Remember that organic controls break down quickly (that’s a good thing; we don’t want the control to hang around for too long). So you will need to reapply the Neem Oil until they are all gone.
Be sure to spray the areas where you see the mealybugs congregate, especially in the folds of the leaves. For any control, the three questions you want the instruction label to answer are:
When to and not to apply?
How to apply?
How frequently to reapply?
Be informed and be safe, and thanks to Colette, for your question.