philodendron dark lord

Cause

On philodendrons, brown or yellow leaves develop when the plant is under heat stress, the air is too dry, the soil swings too dry or too wet, or cold tap water is applied straight from the tap; pale, weak growth compounds the picture when light is too low or nitrogen-heavy feed is pushed during already-dim conditions.

Solutions

• Use tepid or room-temperature water that has been allowed to stand overnight so the roots never see a cold shock, and keep the soil in a steady moist-but-not-soggy band rather than letting it crash between bone-dry and waterlogged.
• Stabilize the environment by pulling the plant away from heat sources, raising humidity with weekly tepid misting, and giving it bright indirect light so the chlorosis tied to dim conditions and nitrogen overload can clear.

Cause

Philodendrons collapse when the root zone is starved of oxygen because the mix holds water or the pot has no drainage, and the chart in Jack Kramer's 1974 monograph on the genus lists collapse of plant as the symptom that pairs with root rot from poor drainage.

Solutions

• Repot into a chunky, free-draining aroid mix of regular potting soil, perlite and orchid bark so oxygen can reach the roots, and make sure the new container has drainage holes that actually let excess water escape.
• Allow the top inch of mix to dry before watering again, pour off any water that collects in the saucer or cachepot, and cut away any soft, blackened roots back to healthy white tissue before returning the plant to fresh dry mix.

Cause

White cottony clusters tucked into the stem and leaf axils of a philodendron, with undersized foliage and spindly new growth behind them, are the calling card of mealybugs feeding on the sap stream.

Solutions

• Dab individual mealybugs off the stems and axils with a cotton swab dipped in rubbing alcohol, then rinse the whole plant with tepid water to clear the residue and any wandering crawlers.
• For a heavier outbreak, spray the entire plant with a Malathion solution covering leaves, stems and undersides, or apply a granular systemic insecticide to the soil so the plant draws the chemistry up through its roots and poisons the feeding pests.

Cause

Microscopic red spider mites move in when the air around a philodendron is dry and dusty, fine webs appear at the leaf and stem axils and beneath the foliage, and the leaves start to mottle, then turn gray, brown and crumbly as the colony drains the cells.

Solutions

• Hit the plant with a vigorous tepid water spray from above and underneath to physically break the webs and dislodge the mites, then repeat the wash weekly so newly hatched mites never get a foothold.
• If the wash alone does not clear them, follow up with a miticide such as Dimite or Aramite sprayed on the whole plant including the undersides, and isolate the philodendron from neighbours while you treat it.