There’s nothing worse than noticing yellowing leaves, sticky residue, or tiny bugs crawling on your beloved houseplants. Whether you’re a novice planter or a seasoned plantaholic, pests and diseases can happen to anyone—it’s just part of plant care. Even with the best attention to watering, lighting, and humidity, fungi, bacteria, and insects can still find their way into your indoor jungle. If left untreated, these unwanted guests can spread quickly and damage your plants.
The good news? Most houseplant pests and diseases are treatable with the right approach. Below, we’ll cover the most common pests, fungi, and infections—plus proven ways to prevent and treat them, so your plants can stay healthy and thriving.
Common Houseplant Pests & How to Treat Them
Spider Mites 🕷️
Image: Patch Plants
Symptoms: Tiny yellow speckles on leaves, webbing under leaves or between stems.
Cause: Low humidity and dry conditions.
Treatment:
✔️ Rinse the plant with water to remove mites and webs.
✔️ Increase humidity with a humidifier or misting.
✔️ Apply neem oil or insecticidal soap every few days.
✔️ Isolate the plant to prevent spread.
Mealybugs 🪳
Image: The Spruce
Symptoms: White, cotton-like clumps in leaf joints and along stems.
Cause: Overwatering, excessive fertilizer, or infested new plants.
Treatment:
✔️ Remove with a cotton swab dipped in rubbing alcohol.
✔️ Spray with neem oil or insecticidal soap.
✔️ Keep infected plants away from healthy ones.
Aphids 🐜
Image: Gardeners' World
Symptoms: Small green, black, or brown bugs on stems and undersides of leaves; sticky residue (honeydew).
Cause: Over-fertilization, new plant introductions, or weak plant immunity.
Treatment:
✔️ Rinse the plant with lukewarm water to knock off aphids.
✔️ Spray with neem oil or insecticidal soap.
✔️ Introduce ladybugs (if you have an outdoor space).
Fungus Gnats 🦟
Image: Kiwi Nurseries Ltd
Symptoms: Tiny black flying bugs near the soil; yellowing, droopy leaves from root damage.
Cause: Overwatering and excess moisture in the soil.
Treatment:
✔️ Let the top 1-2 inches of soil dry out before watering.
✔️ Use sticky traps to catch adults, like the yellow sticky trap in the photo.
✔️ Sprinkle diatomaceous earth or mosquito bits on the soil to kill larvae.
Scale Insects 🛑
Image: Greenery Unlimited
Symptoms: Small brown or tan bumps on leaves and stems; sticky residue.
Cause: Weak plants, low humidity, and nearby infested plants.
Treatment:
✔️ Scrape off visible scale with a toothpick or cotton swab dipped in alcohol.
✔️ Apply horticultural oil or neem oil weekly.
✔️ If infestation is severe, prune affected areas.
Common Houseplant Diseases & How to Treat Them
Powdery Mildew 🌫️
Image: UK Houseplants
Symptoms: White or gray powder-like substance on leaves.
Cause: Poor airflow and excess moisture.
Treatment:
✔️ Improve air circulation around plants.
✔️ Spray leaves with a mix of baking soda and water (1 tsp per quart).
✔️ Reduce humidity and avoid wetting the leaves when watering.
Root Rot 💦
Image: Niche Plant Shop
Symptoms: Wilting, yellowing leaves, mushy roots, and a rotten smell.
Cause: Overwatering and poor drainage.
Treatment:
✔️ Remove the plant from its pot and trim away any black, mushy roots.
✔️ Repot in fresh, well-draining soil.
✔️ Allow the soil to dry out between waterings to prevent recurrence.
Leaf Spot (Bacterial or Fungal) 🍂
Image: Gardenia.net
Symptoms: Brown or black spots on leaves, often surrounded by a yellow halo.
Cause: Overwatering, lack of airflow, and high humidity.
Treatment:
✔️ Remove infected leaves and improve air circulation.
✔️ Avoid getting water on leaves when watering.
✔️ Apply a copper-based fungicide for fungal infections.
How to Prevent Houseplant Pests & Diseases
• Quarantine new plants for at least two weeks before introducing them to your collection.
• Inspect plants regularly for pests and remove any visible bugs immediately.
• Avoid overwatering and ensure you use well-draining soil to prevent root rot.
• Maintain consistent humidity levels without excessive moisture, as fungal infections thrive in damp conditions.
• Use grow lights like the Aspect™ Pendant Grow Light to ensure optimal lighting for your plants while minimizing excess heat and humidity buildup.
• Prune dead or yellowing leaves to improve airflow and reduce the risk of bacterial or fungal spread.
Final Thoughts: Keep Your Houseplants Happy & Pest-Free
Dealing with pests and diseases is a natural part of plant care, but quick action can make all the difference in keeping your plants healthy and thriving. By maintaining good watering habits, proper airflow, and regular plant checks, you can prevent most infestations before they start.
Need to give your plants an extra boost? Check out Soltech’s full-spectrum grow lights to provide healthy, natural-looking light that supports strong plant growth, helping them stay resilient against pests and disease year-round!
