Troubleshooting
Campbell's Magnolia problems — and how to fix them
Campbell's Magnolia (Magnolia campbellii) 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.
Late frost damage to flowers
The blooms emerge in late winter and are extremely susceptible to frost; a single night of -1°C or below destroys the display. Site in a sheltered frost-free microclimate.
Coral spot (Nectria)
Bright orange fungal pustules on dead wood; prune back to healthy tissue and sterilise tools between cuts.
Honey fungus (Armillaria)
Causes rapid decline; there is no cure — remove infected stumps and roots. Avoid replanting susceptible species in the same site.
Long juvenile period
Seed-raised plants typically take 20-25 years to first flower; for earlier blooming, purchase grafted plants which may flower in 5-10 years.
Iron chlorosis
Yellow leaves in alkaline soils; apply chelated iron and mulch with acidic leaf mould. Magnolias are intolerant of high soil pH.
Prevent campbell's magnolia problems before they start
Most campbell's magnolia issues are care-mismatch, not bad luck. Dial in the basics:
Campbell's Magnolia problems — FAQ
Why is my campbell's magnolia late frost damage to flowers?
The blooms emerge in late winter and are extremely susceptible to frost; a single night of -1°C or below destroys the display. Site in a sheltered frost-free microclimate.
Why is my campbell's magnolia coral spot (nectria)?
Bright orange fungal pustules on dead wood; prune back to healthy tissue and sterilise tools between cuts.
Why is my campbell's magnolia honey fungus (armillaria)?
Causes rapid decline; there is no cure — remove infected stumps and roots. Avoid replanting susceptible species in the same site.
Why is my campbell's magnolia long juvenile period?
Seed-raised plants typically take 20-25 years to first flower; for earlier blooming, purchase grafted plants which may flower in 5-10 years.
Why is my campbell's magnolia iron chlorosis?
Yellow leaves in alkaline soils; apply chelated iron and mulch with acidic leaf mould. Magnolias are intolerant of high soil pH.