Treating Scale on Philodendron Selloum and Fixing Brown Leaf Edges

Treating Scale on Philodendron Selloum and Fixing Brown Leaf Edges

A reader’s Philodendron selloum (Lacy Tree) developed yellow leaf edges that turned brown and dry, plus small, round, black plaques on stems and leaves that could be picked off. The plant sits in bright indirect light between east and west windows. The issue appeared after bringing home an infested Ornithogalum dubium that introduced aphids and spider mites to nearby African violets.

Identification: Scale Insects

The black plaques are scale insects—dark, slightly raised bumps about the size of a match head. They scrape off easily, leaving a white residue. If no sticky honeydew is present, the scales are likely dead and only their empty shells remain.

Treatment for Live Scale

1. Mix a spray of 1 part rubbing alcohol, 5 parts water, and a squirt of liquid dish soap.
2. Thoroughly spray all leaf and stem surfaces until dripping (best done outdoors).
3. Wipe away visible scales with a paper towel or soft cloth.
4. Repeat weekly for 3–4 weeks to catch newly hatched crawlers.

Brown Leaf Edges: Unrelated to Scale

Brown edges are typically caused by inadequate light or improper watering.

• Move the plant within 5 feet of an uncovered sunny window.
• Water thoroughly only when the top 1–2 inches of soil are dry.
• Ensure the pot has drainage holes; empty the saucer after watering.
• If tap water is hard, use filtered or distilled water.
• Stop fertilizing until the plant recovers.

For detailed guides on pest control and Philodendron care, email wcreed@HorticulturalHelp.com.