Pest identification
What's eating my pennyroyal?
Aphids
Signs: Clustered soft insects on shoot tips; yellowing, distorted leaves; honeydew and sooty mold below colonies.
Control: Strong water jet; insecticidal soap or neem oil; encourage beneficial insects.
Mint flea beetle
Signs: Numerous small round holes in leaves giving a shot-hole appearance; plants look tattered.
Control: Pyrethrin spray; remove leaf litter in autumn; row cover over young plants in spring.
Slugs & snails
Signs: Irregular holes and missing sections of stems, especially on lower, shaded growth.
Control: Iron phosphate pellets; hand-pick at night; improve drainage around planting area.
Spider mites
Signs: Fine bronzed stippling on leaves; tiny mites and webbing on undersides in hot, dry weather.
Control: Increase humidity; neem oil or insecticidal soap spray; remove worst-affected stems.
Keep pennyroyal pest-free
Healthy plants resist pests best. Get the basics right:
Pennyroyal pests — FAQ
What is eating my pennyroyal?
Pennyroyal's powerful pulegone scent deters many insects but aphids still colonize soft new growth reliably, and slugs will eat low-growing stems in moist spots. Spider mites appear during summer heat. Flea beetles make characteristic shot-holes in the leaves. The plant's spreading habit means pests can move quickly across a patch.
How do I get rid of aphids on pennyroyal?
Clustered soft insects on shoot tips; yellowing, distorted leaves; honeydew and sooty mold below colonies. Strong water jet; insecticidal soap or neem oil; encourage beneficial insects.
How do I get rid of mint flea beetle on pennyroyal?
Numerous small round holes in leaves giving a shot-hole appearance; plants look tattered. Pyrethrin spray; remove leaf litter in autumn; row cover over young plants in spring.
How do I get rid of slugs & snails on pennyroyal?
Irregular holes and missing sections of stems, especially on lower, shaded growth. Iron phosphate pellets; hand-pick at night; improve drainage around planting area.
How do I get rid of spider mites on pennyroyal?
Fine bronzed stippling on leaves; tiny mites and webbing on undersides in hot, dry weather. Increase humidity; neem oil or insecticidal soap spray; remove worst-affected stems.