Rhododendron racemosum Fine Webbing - Causes & Fixes

Jump to cause: Spider Mites (Tetranychidae) Thrips Infestation High Humidity/Microbial Colonies

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Spider Mites (Tetranychidae)

Spider mites thrive in hot, dry conditions and feed on the undersides of Rhododendron leaves, secreting silk that forms fine webbing. This piercing-sucking habit leads to stippling (tiny white/yellow dots) and eventual leaf drop.

Very Common

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How to confirm: Tap a leaf over a white piece of paper; if tiny crawling specks fall off, you have mites.

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shopping_cart Recommended Products

1 Apply an organic insecticide/miticide spray to the plant, ensuring you thoroughly coat the undersides of the leaves where mites reside.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

2 Increase local humidity and avoid hot, dry air by misting the foliage regularly to create an environment less favorable to spider mites.

Flora Premium Plant Mister

Spray Bottles

$12

In Stock

3 Monitor soil moisture levels to ensure the plant is not under drought stress, which can exacerbate mite infestations.

GROWIT Soil Moisture Meter - Blue

Water Meters

$12

In Stock

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Thrips Infestation

While less known for heavy webbing than mites, certain thrips species can create silk-like structures or cause silvering of the leaf surface that mimics web damage. They feed on the epidermal cells of the Rhododendron foliage.

Common

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How to confirm: Look closely at the leaf surface for tiny, slender, elongated insects moving rapidly.

build How to fix it

shopping_cart Recommended Products

1 Apply an organic insecticide spray to the foliage to eliminate active thrips and disrupt their life cycle.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

2 Inspect the undersides of leaves for silvering or tiny insects, and use yellow sticky traps to monitor and capture adult thrips.

Super Ninja Fungus Gnat Traps - 30 Pack

30 pcs

$7

In Stock

3 Prune and dispose of heavily infested or damaged leaves to prevent the spread of the infestation to healthy parts of the plant.

Fiskars 5/8" Bypass Pruning Shears

Cutting Tools

$13

In Stock

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High Humidity/Microbial Colonies

In extremely humid environments with poor airflow around the Tree Rhododendron, certain fungal or bacterial colonies can produce fine, thread-like mycelium that may appear as webbing.

Rare

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How to confirm: Check if the 'webbing' is actually fuzzy growth directly attached to decaying leaf tissue.

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shopping_cart Recommended Products

1 Improve airflow around the plant by pruning dense foliage and spacing it away from other plants to reduce stagnant, humid air.

2 Apply an organic fungicide to treat the fungal colonies and prevent further mycelium spread.