Lichens on Crape Myrtle: Identification and Non-Chemical Management

The gray-green, coral-like growth on your crape myrtle’s limbs is **lichens**—a harmless symbiosis of fungi and algae. They are epiphytes, not parasites, and indicate good air quality and a somewhat open canopy.

Why Copper/Baking Soda Isn't the Answer

• Copper fungicides (e.g., Kocide) may temporarily suppress lichens but are **not labeled for lichen control**.
• Baking soda (0.4 lb/gal) has anecdotal use but no scientific backing and can accumulate sodium in soil.
• Both require full canopy coverage (trunk + limbs) and reapplication—labor-intensive for cosmetic gain.

Effective Strategy: Improve Tree Vigor

1. **Fertilize:** 10-10-10 at 1 lb per inch of trunk diameter, scattered under canopy, watered in.
2. **Water deeply** during dry spells.
3. **Mulch** 2–3 inches (not against trunk) to conserve moisture.
4. **Prune** only for structure/health—denser canopy = more shade = less lichen photosynthesis.

Bottom Line

Lichens are a **symptom of thin canopy**, not a cause of decline. A vigorous, well-foliaged crape myrtle will naturally outcompete them. Enjoy the tree; skip the chemicals.