Troubleshooting
Lobbi Japanese Cedar problems — and how to fix them
Lobbi Japanese Cedar (Cryptomeria japonica 'Lobbii') 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.
Winter bronzing
Foliage turns bronze-brown in cold, dry winters, particularly when exposed to wind. This is a normal physiological response in colder climates, not disease — colour returns to green in spring. Protect young trees with windbreak fleece in exposed positions.
Cryptomeria bark scale
Nuculaspis cryptomeriae (bark scale) can infest stems, causing yellowing and resin exudate. Treat with horticultural oil in late spring when crawlers are active. Improve air circulation and avoid over-crowding to reduce risk.
Stem canker (Seiridium)
Seiridium species cause sunken, resinous cankers and dieback of branches. More prevalent in drought-stressed or heat-damaged trees. Prune out infected wood to healthy tissue, sterilise tools between cuts, and avoid water stress.
Prevent lobbi japanese cedar problems before they start
Most lobbi japanese cedar issues are care-mismatch, not bad luck. Dial in the basics:
- Common japanese cedar bonsai problems — the species this cultivar belongs to
- What's wrong with my plant? — the diagnosis apps compared
- Lobbi Japanese Cedar watering schedule
- Lobbi Japanese Cedar light requirements
- Best soil mix for lobbi japanese cedar
- Lobbi Japanese Cedar temperature & humidity
- Full lobbi japanese cedar care guide
Looking for lobbi japanese cedar in general rather than its problems? Read the full lobbi japanese cedar care guide — light, water, soil and feeding.
Lobbi Japanese Cedar problems — FAQ
Why is my lobbi japanese cedar winter bronzing?
Foliage turns bronze-brown in cold, dry winters, particularly when exposed to wind. This is a normal physiological response in colder climates, not disease — colour returns to green in spring. Protect young trees with windbreak fleece in exposed positions.
Why is my lobbi japanese cedar cryptomeria bark scale?
Nuculaspis cryptomeriae (bark scale) can infest stems, causing yellowing and resin exudate. Treat with horticultural oil in late spring when crawlers are active. Improve air circulation and avoid over-crowding to reduce risk.
Why is my lobbi japanese cedar stem canker (seiridium)?
Seiridium species cause sunken, resinous cankers and dieback of branches. More prevalent in drought-stressed or heat-damaged trees. Prune out infected wood to healthy tissue, sterilise tools between cuts, and avoid water stress.