Managing Leaf Miners in Tomato Seedlings

A gardener has battled leaf miners in tomato seedlings for three years across three different seed-starting mixes. Trails appear as soon as first true leaves emerge.

Understanding Leaf Miners

Leaf miners don't originate from soil or seed-starting mixes—they're larvae of flying insects that lay eggs on foliage. The larvae tunnel between leaf surfaces, making them immune to most spray treatments. Systemic pesticides can't be used on edibles.

Control Strategies

• Maintain plant health with proper watering, fertilizer, and control of more damaging pests
• Remove and destroy mined leaves (but keep first seedling leaves even if mined—they still photosynthesize)
• Scrape off egg clusters as they appear
• Apply neem oil—safe on edibles up to day before harvest, also controls other insects

Leaf miners rarely cause serious harm, but keeping populations low is prudent.

Additional Resources

Further questions welcome via follow-up.