Troubleshooting
Little Gem Magnolia problems — and how to fix them
Little Gem Magnolia (Magnolia grandiflora 'Little Gem') 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.
Chlorosis on alkaline or waterlogged soil
Interveinal yellowing of leaves is most commonly caused by iron or magnesium deficiency on alkaline soils or in waterlogged conditions; improve drainage, acidify with ericaceous compost or sulphur, and apply chelated iron or sequestered iron foliar feed.
Frost damage to evergreen foliage
While hardier than the species, 'Little Gem' can suffer bronzing and dieback of young foliage in harsh winters below -10°C; plant in a sheltered, south-facing position in the UK and colder parts of Zone 7, and avoid exposed positions where desiccating cold winds compound frost damage.
Magnolia scale (Neolecanium cornuparvum)
Soft scale insects colonize stems, excreting honeydew that supports sooty mould, weakening the tree; treat with horticultural oil applied in late winter (dormant) or contact insecticide targeting crawlers in summer.
Prevent little gem magnolia problems before they start
Most little gem magnolia issues are care-mismatch, not bad luck. Dial in the basics:
Little Gem Magnolia problems — FAQ
Why is my little gem magnolia chlorosis on alkaline or waterlogged soil?
Interveinal yellowing of leaves is most commonly caused by iron or magnesium deficiency on alkaline soils or in waterlogged conditions; improve drainage, acidify with ericaceous compost or sulphur, and apply chelated iron or sequestered iron foliar feed.
Why is my little gem magnolia frost damage to evergreen foliage?
While hardier than the species, 'Little Gem' can suffer bronzing and dieback of young foliage in harsh winters below -10°C; plant in a sheltered, south-facing position in the UK and colder parts of Zone 7, and avoid exposed positions where desiccating cold winds compound frost damage.
Why is my little gem magnolia magnolia scale (neolecanium cornuparvum)?
Soft scale insects colonize stems, excreting honeydew that supports sooty mould, weakening the tree; treat with horticultural oil applied in late winter (dormant) or contact insecticide targeting crawlers in summer.