All Leaves Died Off My Phormium After Treating With Horticulture Oil For Mealy Bug

Question

I discovered my 8 young phormium (black adder, special order, hard to find and replace) had mealy bug so I sprayed each and every leaf fold with horticulture spray (called All Seasons) 6 are doing ok but 2 of them had leaves that dried up almost completely. I found that the leaves fell off easily if I plucked or even just moved them. The leaves felt dry except at the very base where they were still green. (About 1/4 inch at most) From these 2, one of them still has a few normal looking leaves, the other lost all leaves and I’m wondering if it will rebound considering the base shows some signs of life (green)

Answer 1

With any oil based sprays, it is very important to follow all packaging instructions very carefully. Oil sprays are not meant to be used in hot weather, or in bright light. These conditions will cause the oils to burn the leaves. It is also very important to, only, test on a very small portion of the plant to make sure that it does not have a reaction to the oil.

I would try and force growth from the top, first. As long as the stems are not brittle they will likely leaf back out. If the top will not leaf back out, then you can allow any growth from the bottom to take back over.

Here are some articles that will help:

https://www.gardeningknowhow.com/plant-problems/pests/insects/mealybugs-control.htm

https://www.gardeningknowhow.com/special/organic/what-are-organic-pesticides.htm

https:/c/www.gardeningknowhow.com/special/organic/natural-home-pesticides-organic-garden-pest-control.htm