Troubleshooting
Rhododendron 'Nova Zembla' problems — and how to fix them
Rhododendron 'Nova Zembla' (Rhododendron 'Nova Zembla') 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.
Iron chlorosis
Yellow leaves with green veins in near-neutral or alkaline soil. Acidify the planting area with sulphur or ericaceous compost; apply chelated iron as an interim treatment.
Winter burn
Desiccation of leaves from cold, drying winter winds. Site in a sheltered position or use an anti-desiccant spray before severe cold periods.
Phytophthora root rot
Fatal fungal root disease in waterlogged soil. Excellent drainage is the only reliable prevention. Do not over-irrigate.
Spider mites
Fine stippling of foliage in hot, dry conditions. Increase humidity and water regularly; treat with a miticide if populations become large.
Flower bud drop in cold snaps
Buds can abort if exposed to sharp late frosts after swelling has begun. Protect with horticultural fleece when late frosts are forecast in spring.
Prevent rhododendron 'nova zembla' problems before they start
Most rhododendron 'nova zembla' issues are care-mismatch, not bad luck. Dial in the basics:
Rhododendron 'Nova Zembla' problems — FAQ
Why is my rhododendron 'nova zembla' iron chlorosis?
Yellow leaves with green veins in near-neutral or alkaline soil. Acidify the planting area with sulphur or ericaceous compost; apply chelated iron as an interim treatment.
Why is my rhododendron 'nova zembla' winter burn?
Desiccation of leaves from cold, drying winter winds. Site in a sheltered position or use an anti-desiccant spray before severe cold periods.
Why is my rhododendron 'nova zembla' phytophthora root rot?
Fatal fungal root disease in waterlogged soil. Excellent drainage is the only reliable prevention. Do not over-irrigate.
Why is my rhododendron 'nova zembla' spider mites?
Fine stippling of foliage in hot, dry conditions. Increase humidity and water regularly; treat with a miticide if populations become large.
Why is my rhododendron 'nova zembla' flower bud drop in cold snaps?
Buds can abort if exposed to sharp late frosts after swelling has begun. Protect with horticultural fleece when late frosts are forecast in spring.