Philodendron plants are popular for their lush foliage and relatively easy care. Even resilient plants can encounter issues, so recognizing problems early is key to maintaining their health. Observing visual cues helps diagnose what might be affecting your philodendron, allowing prompt action.
Identifying Common Philodendron Pests
Spider mites are tiny arachnids, barely visible, appearing as small, moving dots on leaf undersides. A key sign is fine webbing between leaves and stems. Infested leaves show tiny yellow or white stipples, and severe cases cause leaves to turn bronze or yellow before dropping.
To treat, spray water to dislodge them. Apply insecticidal soap or neem oil to all leaf surfaces every 5-7 days for several weeks. Higher humidity discourages them.
Mealybugs are soft, white, cottony masses found in leaf axils or along stems. They excrete sticky honeydew, leading to sooty mold. Infested plants show stunted growth, yellowing leaves, and distorted new growth.
For light infestations, dab pests with a rubbing alcohol-dipped cotton swab. For widespread issues, apply insecticidal soap or horticultural oil, repeating weekly to eliminate nymphs.
Aphids are small, soft-bodied insects (green, black, or brown) that cluster on new growth, leaf undersides, and stems, forming visible colonies. Signs include curled, distorted, or yellowing leaves, and sticky honeydew.
Dislodge them with a strong water stream. Apply insecticidal soap or neem oil, treating every few days for a couple of weeks to break their life cycle.
Scale insects appear as small, immobile brown, black, or tan bumps with a waxy coating on stems and leaves. They produce honeydew, causing sticky residue and sooty mold.
For small numbers, scrape them off or dab with rubbing alcohol. For larger infestations, apply neem oil or insecticidal soap; multiple treatments are often needed.
Fungus gnats are small, dark, flying insects hovering around soil. Adults are a nuisance, but larvae in the soil feed on decaying matter and sometimes roots.
Control involves drying the topsoil between waterings to disrupt breeding. Sticky traps catch adults. For severe cases, Bti (Bacillus thuringiensis israelensis) dunks or granules target larvae in the soil.
Diagnosing Philodendron Leaf Issues
Yellowing Leaves
Yellowing leaves suggest various issues. Uniform yellowing of older, lower leaves often indicates underwatering or natural aging. Widespread yellowing, especially on younger leaves or with mushy stems, points to overwatering and potential root rot.
Yellowing between veins (interveinal chlorosis) with green veins suggests a nutrient deficiency. Adjust watering: increase for underwatering, allow thorough drying for overwatering, ensuring good drainage. Too little or excessive direct light can also cause yellowing.
Browning Leaf Tips or Edges
Browning leaf tips or edges often signal low humidity or watering issues. Dry air causes crisp, brown margins, common in heated indoor spaces. Insufficient watering also leads to browning edges.
Over-fertilization can cause salt buildup, burning leaf tips. Remedy low humidity with misting or a humidifier. For underwatering, ensure consistent watering, letting topsoil dry. If fertilizer burn is suspected, flush soil with plain water.
Drooping or Wilting Leaves
Drooping or wilting leaves indicate distress, often from too much or too little water. Limp leaves with dry soil mean underwatering; thorough watering usually revives them. Drooping leaves with consistently wet soil indicate overwatering and root rot, as roots suffocate.
Other causes include sudden temperature changes or transplant shock. For overwatering, reduce frequency and ensure drainage; repotting with fresh, well-draining soil may be needed if root rot is suspected.
Spots and Lesions on Leaves
Spots and lesions vary from small specks to discolored patches. Brown or black spots with yellow halos suggest fungal or bacterial leaf spot diseases, common in humid or poorly ventilated conditions. Sunburn appears as bleached or crispy brown spots on leaves exposed to direct sun.
Water spots, from mineral deposits, are white or grayish marks. Manage disease with good air circulation; avoid wetting leaves. Move sunburned plants to indirect light. Use filtered water for misting to prevent water spots.
Stunted or Small Leaves
Stunted or small new leaves, or stalled growth, indicate issues. Insufficient light is common, as plants need light for leaf development; low light causes leggy growth with small foliage.
Nutrient deficiencies also restrict leaf size if fertilizer is inadequate. A root-bound plant, with tightly circling roots, also shows stunted growth. Repot into a slightly larger container with fresh potting mix for root-bound conditions. Adjust light and provide regular, diluted fertilizer during spring and summer to encourage larger leaves.
Understanding Philodendron Stem and Root Problems
Mushy Stems or Roots
Mushy stems or roots clearly indicate root rot, caused by overwatering and poor drainage. Saturated soil deprives roots of oxygen, causing them to decay, becoming soft, brown, or black, often with a foul odor. This decay can spread to the stem.
To address, remove the plant, prune rotted sections with clean shears. Repot into a clean pot with fresh, well-draining potting mix and ample drainage. Allow the top few inches of soil to dry completely before watering.
Leggy Growth
Leggy growth features long, stretched stems with sparse leaves and elongated internodes, indicating the plant is seeking more light. Philodendrons thrive in bright, indirect light; low light causes them to grow taller.
To correct, move the plant to a brighter, indirect light location. Pruning leggy stems encourages bushier growth by stimulating new shoots. Avoid direct, harsh sunlight to prevent scorching.
Lack of New Growth
A lack of new growth, or stalled activity, during the active growing season indicates stress. Insufficient light is a frequent cause, limiting photosynthesis and energy for new growth.
Nutrient deficiencies also hinder growth if the potting mix is depleted. A severely root-bound plant may struggle due to a restricted root system. Ensure adequate bright, indirect light, regular balanced fertilizer during the growing season, and consider repotting if root-bound.
Preventative Care and General Troubleshooting
Consistent environmental checks are foundational for philodendron care. Provide bright, indirect light, avoiding deep shade or harsh direct sun. Maintain stable temperatures (65-80°F / 18-27°C) and protect from cold drafts. Philodendrons appreciate higher humidity, achievable through misting or humidifiers.
Proper watering is crucial: check soil moisture, allowing the top inch or two to dry between waterings. Ensure pots have drainage holes to prevent water accumulation and root rot.
Good air circulation prevents fungal issues; avoid crowding plants. Regularly inspect for early signs of pests or disease for quicker intervention.
For complex or persistent problems, consult local nurseries or online communities. Continuous observation and proactive care maintain a healthy philodendron.