Common Pests (Identify & Fix)

Quick ID cards with simple fixes you can try the same day — safe for edibles and containers.

Aphids clustered on a tender stem

Aphids

StickyCurled tipsAnts nearby

  • Blast with water; repeat after 2–3 days (undersides).
  • Mild soapy water wipe (rinse next day on edibles).
  • Attract ladybirds with dill, fennel, calendula.
Fine webbing and speckled leaves

Spider Mites

Fine webSpeckled leavesDry air

  • Mist daily to raise humidity; shower gently weekly.
  • Wipe leaf undersides; increase airflow.
  • Isolate heavily affected pots.
Slugs damage with silvery trails

Slugs & Snails

Big holesSilvery trails

  • Evening hand-pick; copper tape around pots.
  • Beer traps; wool pellets; tidy damp hiding spots.
  • Raise pots on feet; avoid heavy night watering.
Whitefly rising in a small cloud

Whitefly

Little white cloudSticky leaves

  • Yellow sticky cards near plant canopy.
  • Wipe with soapy water; rinse next day.
  • Boost airflow; avoid crowding foliage.
Pale, snaking tunnels in leaves

Leaf Miner

Snake trailsThin tunnels

  • Remove affected leaves promptly (bin, don’t compost).
  • Use fine mesh over susceptible crops.
Brown lesions and blackened stems

Tomato/Potato Blight

Brown patchesBlackened stemsRapid collapse

  • Remove affected growth; do not compost.
  • Water soil, not leaves; increase spacing/airflow.
  • Choose earlier/determinate tomatoes for pots.
Tiny gnats on the compost surface

Fungus Gnats

Tiny fliesOn wet compost

  • Let top 2–3 cm dry between watering.
  • Top dress with coarse sand/grit.
  • Yellow sticky traps near soil surface.
White powdery coating on leaves

Powdery Mildew

White powderDry still air

  • Prune for airflow; avoid late overhead watering.
  • Remove worst leaves; keep new growth vigorous.
Black vine weevil on a leaf

Vine Weevil

Notches on leavesRoot-eating grubs

  • Check at night for adults; hand-pick.
  • Repot badly hit plants, removing grub-filled compost.
  • Use biological nematodes (labelled for vine weevil) in warm months.
Tiny flea beetle on brassica leaf with small holes

Flea Beetle

Tiny shot holesJumps when disturbed

  • Use fine mesh over young brassicas/rocket.
  • Keep plants growing fast with even moisture.
  • Interplant with strong-scented herbs to confuse.
Cabbage white butterfly and caterpillars on brassicas

Cabbage White (Caterpillars)

Butterflies hoveringGreen caterpillars

  • Fine mesh over brassicas; check for eggs under leaves.
  • Hand-pick caterpillars early.
  • Grow decoy nasturtiums nearby to draw attention.
Collapsed seedlings at soil line from damping-off

Damping-off (Seedlings)

Seedlings collapseBrown stem at soil

  • Use fresh seed compost and clean trays.
  • Avoid overwatering; give bright light and airflow.
  • Sow a little thinner; bottom-water when possible.

Are Nematodes Safe?

Biological controls like nematodes are often misunderstood. Here’s the quick guide:

  • Slug nematodes (Phasmarhabditis) only affect small soil-dwelling slugs. They don’t harm earthworms, pets, bees, or people.
  • Vine weevil nematodes (Steinernema/Heterorhabditis) attack only the larvae that chew roots. Adults still need hand-picking. Pollinators are not affected.
  • Safe for pollinators: these nematodes don’t infect bees, butterflies, or other garden helpers.
  • Best results: apply to moist soil in warm conditions and repeat through the season.

Summary: nematodes are a natural, targeted way to control pests in pots and beds without harming pollinators or pets.

Use food-safe methods first for edibles. Repeat gentle controls rather than one harsh hit.