Common Anthurium Plant Problems and How to Fix Them

Anthurium plants, known for their glossy, heart-shaped leaves and vibrant spathes, bring a tropical feel to any home. While straightforward to care for, they have specific needs and will show distinct signs when those needs are not met. This guide will help you diagnose and fix the most frequent issues to keep your plant healthy and blooming.

Anthurium Leaf Problems

Yellow Leaves (Chlorosis)

Yellowing leaves (chlorosis) often indicate an underlying issue. The most frequent cause is overwatering, which leads to waterlogged soil and prevents roots from accessing oxygen. Check for this by feeling the soil; if the top inch is still moist, delay watering.

Nutrient deficiency is another cause. A lack of nitrogen can cause older, lower leaves to turn yellow first, while a magnesium deficiency might appear as yellowing in a V-shape at the leaf margins. A balanced, water-soluble fertilizer can address this. It is also natural for the oldest, lowest leaves to yellow and eventually drop as the plant matures and directs its energy toward new growth.

Brown, Crispy Leaf Tips/Edges

Brown, crispy leaf edges or tips point to an environmental imbalance. Low humidity is a frequent cause, as these tropical plants thrive in moist air. Increase humidity with a humidifier, by placing the plant on a pebble tray with water, or by grouping it with other plants.

Underwatering can also cause desiccated leaf tips because the plant cannot transport enough water to its extremities. Ensure you are watering thoroughly when the top layer of soil feels dry. Fertilizer burn, from excess salt buildup, can also damage roots and cause brown tips. Prevent this by using a diluted fertilizer and flushing the soil with plain water every few months.

Brown or Black Spots

Isolated brown or black spots on leaves can have several causes. Sunburn from excessive direct light is a primary cause. Placing an anthurium in a south-facing window without a sheer curtain can scorch the leaves, creating dry, brown patches. Relocating the plant to a spot with filtered light will prevent further damage.

Physical damage from bumping or scraping can also result in localized spots as the leaf tissue dies. These spots are cosmetic and not a sign of a larger health problem.

Why Anthuriums Fail to Bloom

The most common reason an anthurium fails to bloom is insufficient light. While they need protection from direct sun, these plants require plenty of bright, indirect light to flower. A plant in a dim corner may produce lush leaves but will likely not bloom. Moving it to a brighter location, such as near an east-facing window, can stimulate flower production.

Improper fertilization is another factor. A fertilizer high in nitrogen promotes foliage growth at the expense of flowers. To encourage blooming, use a balanced fertilizer or one slightly higher in phosphorus. Apply a diluted solution every four to six weeks during the spring and summer growing season.

The plant’s age and environment also play a role. A young anthurium may not be mature enough to flower. Consistent warm temperatures are also a trigger for blooming, as anthuriums thrive in conditions between 70 and 90 degrees Fahrenheit. Avoiding temperature fluctuations helps signal to the plant that it is in a stable environment suitable for flowering.

Common Anthurium Pests

Anthuriums are susceptible to several common houseplant pests that feed on sap and stunt growth. Early detection is important for control. Treatment can involve wiping pests off with a cotton swab dipped in rubbing alcohol or spraying the plant with insecticidal soap or neem oil, covering all surfaces.

• Spider mites are identified by fine, silky webbing on the undersides of leaves and a stippled, faded appearance on the leaf surface. These tiny arachnids thrive in dry conditions, so increasing humidity can help deter them.
• Mealybugs appear as white, cotton-like masses, often hiding in the leaf axils and other protected areas. They secrete a sticky substance called honeydew, which can lead to sooty mold.
• Aphids are another sap-sucking pest that tends to cluster on new, tender growth, causing distortion and yellowing.
• Scale insects present as small, hard bumps on the stems and leaves, effectively camouflaging themselves as part of the plant.

Anthurium Diseases

Pathogen-based diseases in anthuriums are often linked to excess moisture and poor air circulation. Root rot is one of the most serious conditions and is almost always the result of overwatering and soil that does not drain properly. Fungal pathogens in the soil attack the roots, causing them to turn brown and mushy. Above ground, the plant may wilt and its leaves will turn yellow, mimicking the signs of underwatering.

To treat root rot, remove the plant from its pot and inspect the root system. Trim away all blackened, soft roots with sterile scissors and repot the plant into fresh, well-draining soil, such as a mix containing orchid bark and perlite. Reducing watering frequency is necessary to prevent recurrence.

Fungal and bacterial leaf spot diseases can also affect anthuriums. These spots often appear water-soaked or have a distinct yellow halo, distinguishing them from sunburn or fertilizer burn. To manage these diseases, improve air circulation, avoid getting water on the leaves, and promptly remove any affected foliage. A fungicide can be used as a further measure if the infection is severe.