"A Little Secret About Plant Bugs and Disease" or "Why Pesticides Make No Sense"

Here's sooty mold on camellia leaves.

This camellia has never had sooty mold before. Hmm.

Usually, I look under sooty leaves and see scale, that strange juice-sucking bug that attaches to the underside of leaves and stems and forms a seal over itself like a scale. (These pests are very literal.) Scale also excrete a sugary substance that sooty mold (a fungus) likes to grow in. So they often coexist on the same beleaguered plant in a sticky, sooty mess.

I'm not going to give you the name of a product that will magically make this problem disappear, like a household cleaner with a strangely sterile, muscle-y man on the label.

The little secret about plant bugs and diseases is that they wouldn't be there if the plant wasn't already stressed out.

Healthy plants have the right balance of minerals and sugars and water and chemical compounds and faery spirits running through their branches. Bugs and diseases are living things too, and they know when an environment is ideal for setting up camp. At some invisible level, bugs and diseases may actually be repelled by too many healthy vibes--a high level of certain sugars, for example, is an indicator of the presence of other minerals and compounds that may create a hostile environment for pests.

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Pests may not even "see" a plant until its healthy vibes have deteriorated to the point that--chemically or energetically--it is a beacon like a cheap hotel (depending on your definition of beacon).

So I'm not going to fret about the soot. Instead, I'm going to wonder what has changed in the past year, that would have stressed out and blackened this lovely specimen.

Possibility #1: Construction site run-off

For the past couple months, the deck has been under a major renovation, and there is a likelihood that various chemical compounds have found their way down the bank...into the root-zone of the camellia. One such compound is concrete slurry, which is very alkaline. Camellias prefer an acidic soil, so there is a possibility that the pH is off, and the plant can't absorb nutrients.

Possibility #2: Soil compaction

The original low-traffice maintenance pathway veers left, edged by stones. Last year, I re-routed the path around the camellia because heavy snows had collapsed the trunks over the pathway. I suspect that the shallow roots of a camellia don't like being walked on...whoops...so pink flagging tape is now blocking the detour. Allen the Pool Guy and I will just have to hobbit our way through.

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Soil compaction is bad. Without air, life is hard for soil organisms. I've just learned about a compost tea that will introduce aerating soil organisms to compacted soil, and fix it. So I'll try that, but before, I'll set the hose on the area to flush out any toxic residues from the construction.

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Extra Note: Sooty mold also tends to appear on Pieris japonica (Andromeda), Sarcococca (Himalayan sweetbox), and Trachelospermum (Star Jasmine). According to my observation, it tends to affect very old Pieris (they are waning already) and Sweetbox/Star Jasmine that are planted under eaves and suffer from lack of watering in the winter. So they are already stressed.