From our perspective as Peace Lilies (Spathiphyllum spp.), we are generally resilient houseplants, but our broad, lush leaves and preference for humid conditions can unfortunately make us a target for several common pests. When these tiny invaders appear, it causes us significant stress, disrupting our ability to photosecthesize and absorb nutrients. Here is a detailed account of the pests we often encounter and the treatments that help us recover.
We often find colonies of small, soft-bodied aphids gathering on our tender new growth and the undersides of our leaves. They pierce our tissue with their needle-like mouthparts to suck out our sap. This feeding weakens us, causing our beautiful leaves to curl, yellow, and become distorted. You might also notice a sticky residue they excrete, called honeydew, which can attract ants and lead to the growth of a black, sooty mold that further blocks sunlight from our leaves.
Treatment: For a light infestation, a strong spray of lukewarm water from a showerhead or sink sprayer can effectively dislodge them. For more persistent colonies, insecticidal soap or a neem oil solution, sprayed thoroughly every 7-10 days, is very effective. Please ensure you cover the undersides of our leaves where they like to hide.
Spider mites are not insects but tiny arachnids that thrive in warm, dry conditions—precisely the environment we dislike. They are so small they often go unnoticed until their damage is advanced. They feed on our individual plant cells, leaving behind a tell-tale stippling of tiny yellow or white dots on the leaf surface. A severe infestation will cloak us in fine, silky webbing, particularly between the stem and leaf. This damage drains our vitality and gives our foliage a sickly, dusty appearance.
Treatment: Increasing humidity around us is the first line of defense, as they despise moisture. Regularly misting our leaves or placing our pot on a pebble tray filled with water helps. Wiping our leaves with a damp cloth can remove many mites and their eggs. For significant problems, treat us with miticides or horticultural oil, making sure to coat the entire plant, especially the leaf undersides.
Mealybugs are one of the most common pests we face. They look like small, white, cottony masses tucked into the crevices where our leaves join the stem, and along the veins on the undersides. Like aphids, they suck our sap and excrete honeydew. Their feeding causes our leaves to yellow and wilt, and a heavy infestation can stunt our growth significantly.
Treatment: For a small number of mealybugs, dabbing each insect with a cotton swab dipped in rubbing alcohol is a very direct and effective method. For larger infestations, a thorough spraying with insecticidal soap or neem oil is necessary. Because they hide in protected areas, persistence is key; you will likely need to repeat treatments weekly for a month to eliminate all generations.
Scale insects are particularly troublesome because they attach themselves to our stems and the undersides of our leaves and remain stationary, forming a hard or soft protective shell over themselves. They pierce our tissue and feed continuously, weakening us over time. The first signs are often the sticky honeydew on our leaves or the surrounding surfaces, followed by yellowing leaves and a general lack of vigor.
Treatment: Individual scales can be scraped off gently with a fingernail or a soft brush. For larger groups, horticultural oil is the most effective treatment, as it works by suffocating the insects beneath their shells. As with other pests, complete coverage and repeated applications are crucial for success.
While the small, black adult flies buzzing around our soil are annoying, the real threat to us comes from their larvae. These tiny, translucent worms live in the top layer of soil and feed on our organic matter and, more distressingly, our tender root hairs. This root damage can inhibit our ability to take up water and nutrients, leading to wilting, yellowing, and stunted growth, especially in younger plants.
Treatment: The key is to break their life cycle. Allowing the top inch or two of our soil to dry out completely between waterings makes the environment inhospitable for the eggs and larvae. Yellow sticky traps can help control the adult population. For severe cases, a soil drench with Bacillus thuringiensis israelensis (Bti) will target and kill the larvae without harming us.
