In this guide, we cover how to identify common garden pests and natural pest control solutions. Before you read on though, we recommend taking a look at our resource on Integrated Pest Management for the best tips and tricks on preventing pest infestations.
Aphids
Season: Year-Round
Environment: Indoor & Outdoor
About: Aphids feed on plant sap and can infest your plants quickly. They can enter your home through open doors, windows, or by attaching to clothing and pets.
Identification: Aphids come in various colors: green, red, black, brown, and gray. They are usually found on the underside of leaves, leaving behind a sticky substance called "honeydew" and bright white molts.
Treatment:
- Regularly check your plants and harvest them young.
- Squish or wash off aphids into a bucket of water.
- Use predatory insects like Aphidius colemani and Green Lacewings.
- Chemical control: Insecticidal Soap, Pyrethrins, Neem Oil, Spinosad. Follow label instructions.
Fungus Gnats
Season: Year-Round
Environment: Indoor & Outdoor
About: Fungus gnats feed on decaying organic matter and algae. Adult gnats are harmless to plants but can be annoying.
Identification: Look for small, black flying insects and larvae in the substrate.
Treatment:
- Reduce irrigation to control algae.
- Use yellow sticky cards.
- Introduce beneficial nematodes like NemAttack.
- Chemical control: Hydrogen peroxide, Pyrethrins, Insecticidal Soap, Bacillus thuringiensis v. israelensis. Follow label instructions.
Caterpillars
Season: Summer & Fall
Environment: Outdoor
About: Caterpillars are the larval stage of moths and butterflies and can be very destructive to plants.
Identification: Look for green or brown worms, black droppings, and holes in leaves.
Treatment:
- Remove weeds, mulch, and grass.
- Use predatory insects like Trichogramma and Green Lacewings.
- Chemical control: Bacillus thuringiensis, Insecticidal Soap, Pyrethrins. Follow label instructions.
Leaf Miners
Season: Spring & Summer
Environment: Outdoor
About: Leaf miners create tunnels in leaves, causing damage and potential bacterial infections.
Identification: Look for winding tunnels in leaves and damaged tissue.
Treatment:
- Keep plants healthy.
- Squish larvae at the end of tunnels.
- Introduce parasitic wasps like Diglyphus isaea.
- Chemical control: Spinosad, Pyrethrins. Follow label instructions.
Mites
Season: Year-Round
Environment: Indoor & Outdoor
About: Mites are small pests that thrive in warm temperatures and can cause severe damage to crops.
Identification: Look for colonies on the underside of leaves, yellowish stippling, and webbing.
Treatment:
- Rinse and wipe plants.
- Use predatory mites like Persimilis and Amblyseius swirskii.
- Chemical control: Miticide, Insecticidal soap, Pyrethrins. Follow label instructions.
Thrips
Season: Spring & Summer
Environment: Outdoor
About: Thrips feed on plant cells, causing deformed leaves, flowers, and shoots.
Identification: Look for stippling, silvering of leaves, and twisted growth.
Treatment:
- Use sticky cards to monitor.
- Introduce predatory insects like Cucumeris and Green Lacewings.
- Chemical control: Pyrethrins, Neem Oil, Azadirachtin. Follow label instructions.
Snails & Slugs
Season: Spring & Summer
Environment: Outdoor
About: Snails and slugs feed on living and decaying plant material and thrive in wet, shady areas.
Identification: Look for slime trails and irregularly shaped holes in plants.
Treatment:
- Remove hiding places like wood and stones.
- Ensure good airflow and sunlight.
- Use beneficial nematodes like Phasmarhabditis californica.
- Chemical control: Sluggo, Monterey Snail & Slug Spray. Follow label instructions.