Why Is My Boston Fern Turning Yellow? (ANSWERED)

Disclosure: As Amazon Associates we earn from qualifying purchases. When you buy through links on our site, we may earn an affiliate commission at no additional cost to you.

Please note that while we always strive to provide 100% up to date and accurate information, there is always the small possibility of error. Therefore, we advise conducting further research and due diligence before consuming any plants or exposing pets to anything mentioned on this site. Kindly refer to the full disclaimer for more details here.

Sharing is caring!

Boston ferns can be temperamental and may require extra care to thrive. One common issue that many plant owners face is the yellowing of their Boston fern’s fronds. If you are experiencing this problem, you may be wondering why your plant is turning yellow and what you can do to fix it. In this blog post, we will explore the potential causes of yellowing in Boston ferns and provide you with tips to help you restore your plant to its vibrant green glory.

Causes of Yellowing Leaves

Boston ferns may experience yellowing leaves due to a variety of factors. This section will explore the various causes, including watering issues, lighting conditions, nutrient deficiencies, and pests and diseases.

Watering Issues

Improper watering practices, such as overwatering or underwatering, can cause Boston fern leaves to turn yellow. Overwatering can lead to root rot, which prevents the plant from absorbing water and nutrients from the soil, resulting in yellow leaves (Fiddle & Thorn). To avoid this issue, ensure the soil is moist but not soggy, and never let it dry out completely (Simplify Plants).

Lighting Conditions

While Boston ferns prefer indirect sunlight, they still require sufficient lighting to maintain their vibrant green foliage. Insufficient lighting can cause the leaves to turn yellow as the plant struggles to photosynthesize. Conversely, direct sunlight can scorch the leaves, leading to yellowing and browning. Ensure your fern receives filtered or indirect light for optimal growth.

Nutrient Deficiencies

A lack of proper nutrients can result in yellowing leaves. Boston ferns may suffer from nitrogen deficiencies, which can be resolved with balanced houseplant food, such as a 20-20-20 or 20-10-20 formula (Plantophiles). Additionally, ensure the soil composition is suitable for ferns and provides adequate nutrient availability.

Pests and Diseases

Pests and diseases can also lead to yellowing leaves in Boston ferns. Common pests, such as aphids and spider mites, can damage the foliage, causing it to yellow and eventually die. Fungal diseases, such as root rot or leaf spot, may also result in yellowing. Regularly inspect plants for signs of infestation and disease, and treat accordingly with appropriate solutions, such as insecticidal soaps or fungicides.

Prevention and Solutions

Proper Watering

Boston ferns thrive in soil that is moist but not soggy. To prevent yellowing, ensure the soil remains damp without being waterlogged. Monitor the plant’s watering needs by checking the soil’s moisture level and only water when it begins to dry out, but isn’t completely dried out(source).

Ideal Lighting

Provide your Boston fern with indirect, bright sunlight for the best results. Avoid placing the fern directly under strong sunlight, as too much direct light can cause leaf scorching and yellowing. Find a spot with filtered sunlight or diffuse the light with a sheer curtain if needed.


Feed your Boston fern with a balanced, water-soluble fertilizer every four to six weeks during the growing season. This will ensure that the plant has the necessary nutrients to grow healthy and prevent leaf yellowing. Avoid over-fertilizing, as excessive nutrient levels can cause harm to the plant.

Pest and Disease Control

Regularly inspect your Boston fern for signs of pests and diseases. Keep the plant clean and free of debris to minimize the risk of infestations. If you notice signs of pests, treat the affected area with an appropriate pesticide or insecticide. For fungal diseases, remove any infected leaves and improve the plant’s environment to prevent the spread of the disease.

Helpful Video