Rhododendron
An acid-loving evergreen valued for its large, showy late-winter and spring flower trusses. Most garden forms stay a manageable 1-2m, though some species grow into small trees several metres tall - check the specific type before planting. Needs sharp, free-draining, acidic soil (wet feet even briefly can be fatal) and dappled shade, with larger-leaved varieties needing more shade protection than smaller-leaved ones. Thrips, which leave a distinctive silvery mottling on the leaf surface, are a particularly bad problem in North Island gardens.
- Sun
- partial sun
- Water
- moderate
- Spacing
- 150cm
- Difficulty
- intermediate
- Grows in
- Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson, Tasman, Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago, Invercargill / Southland
- Mature height
- 2m
- Flowering season
- Jul, Aug, Sep, Oct
- Attracts wildlife
- Bees
- Evergreen
- Yes
- Common diseases
- Phytophthora root rot, Powdery mildew
- Common pests
- Thrips, Vine weevil
When to plant by region
In Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson and Tasman: March-April and September-October. In Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago and Invercargill / Southland: September-October.
Growing stages
Planting & establishmentFirst few months
- Needs sharp, free-draining, acidic soil; even brief wet feet can be fatal
- Dappled shade suits it best, with larger-leaved varieties needing more shade protection than smaller-leaved ones
- Check whether the specific type stays a manageable 1-2m or grows into a small tree several metres tall
Early growthFirst 1-2 years
- Watch for thrips, which leave a distinctive silvery mottling on leaves and are a particular problem in North Island gardens
- Vine weevil can notch leaf edges and grub on roots
FloweringLate winter into spring
- Large, showy flower trusses attract bees; avoid spraying during flowering
- Continue monitoring for thrips damage as new growth and buds develop
- Phytophthora root rot risk rises after wet periods; watch drainage closely at this stage
Maturity
- Established plants still need consistently free-draining soil; even mature rhododendrons can be killed by waterlogging
- Continue watching for thrips and vine weevil each season