Plant Pest and Disease Guide — Identification and Treatment

Spider mites, scale, aphids, fungus gnats — learn to identify the 6 most common plant pests and diseases and eliminate them before they spread.

No matter how carefully you care for your plants, pests are an occasional reality. The key is early detection: most infestations are easy to treat when caught quickly, but can devastate a collection if ignored.

1. Spider Mites

Look for fine webbing on the undersides of leaves and tiny white or yellow speckles on the leaf surface. Spider mites thrive in dry conditions. Increase humidity, spray leaves with water regularly, or treat with diluted dish soap solution.

2. Scale Insects

Scale appears as brown bumps or white cottony blobs on stems and leaves. Scrape them off manually and wipe the area with a cotton swab dipped in rubbing alcohol. Follow up with neem oil spray.

3. Aphids

Clusters of small green, black, or white insects on new growth and flower buds. Blast them off with a strong stream of water or spray with a diluted neem oil solution. Repeat every 3–4 days for two weeks.

4. Fungus Gnats

Tiny flies hovering around the soil surface. Their larvae feed on roots in wet soil. Let the soil dry out more between waterings, and use yellow sticky traps to catch adults. Hydrogen peroxide watering solution kills larvae.

5. Powdery Mildew

White powdery coating on leaves — a fungal infection caused by poor air circulation. Remove badly infected leaves. Spray with a mix of 1 teaspoon baking soda per 1 litre of water, or use a diluted neem oil treatment.

6. Thrips

Silver streaks or black specks on leaf surfaces indicate thrips. These tiny insects rasp the leaf surface and suck out the contents. Treat with neem oil or insecticidal soap spray, repeated weekly for 3–4 weeks.

Use GreenPic's AI Health Diagnosis — take a photo of the affected leaves and get an instant assessment of what's wrong.