Troubleshooting
Weeping Japanese Larch problems — and how to fix them
Weeping Japanese Larch (Larix kaempferi 'Pendula') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Larch case-bearer (Coleophora laricella)
Small caterpillars mine needles, causing browning. Treat with appropriate insecticide in early spring at egg hatch.
Larch canker (Lachnellula willkommii)
Causes sunken, resinous cankers on branches. Remove and destroy infected wood; ensure good air circulation.
Aphids
Woolly larch aphids may colonise shoots in spring. Treat with insecticidal soap at first sign of infestation.
Poor root anchorage
Weeping forms need firm staking when young. Check and replace stakes as the tree establishes.
Prevent weeping japanese larch problems before they start
Most weeping japanese larch issues are care-mismatch, not bad luck. Dial in the basics:
Weeping Japanese Larch problems — FAQ
Why is my weeping japanese larch larch case-bearer (coleophora laricella)?
Small caterpillars mine needles, causing browning. Treat with appropriate insecticide in early spring at egg hatch.
Why is my weeping japanese larch larch canker (lachnellula willkommii)?
Causes sunken, resinous cankers on branches. Remove and destroy infected wood; ensure good air circulation.
Why is my weeping japanese larch aphids?
Woolly larch aphids may colonise shoots in spring. Treat with insecticidal soap at first sign of infestation.
Why is my weeping japanese larch poor root anchorage?
Weeping forms need firm staking when young. Check and replace stakes as the tree establishes.