Crepe Myrtle Powdery Mildew After Hard Pruning

Your crepe myrtle's slow regrowth (5–6 inches) with white powder and white threads on trunk after hard fall pruning has two issues:

1. Powdery Mildew

• White powder on leaves = classic mildew.
• Hard pruning → dense, succulent regrowth = mildew magnet.
• Treat with myclobutanil, propiconazole, or sulfur. Repeat per label.

2. White Threads on Trunk

• Likely lichen or fungal mycelium on dead bark exposed by pruning.
• Not a disease—just colonizing dead tissue.
• Will disappear as new bark forms.

Recovery Plan

1. Treat mildew now.
2. Thin regrowth to 3–5 strong canes—reduces density, improves air flow.
3. Water deeply weekly; mulch.
4. Next year: prune after bloom (late spring), not fall. Fall pruning stimulates tender growth that winter-kills or gets mildew.

Crepe myrtles bloom on new wood—prune late winter/spring for best form and health.