How to Grow Rhododendrons
Rhododendrons are hardy, evergreen plants that flower from late winter to early spring. They add drama and a pop of colour to your garden, and come in a range of varieties. Growing them is easy, this guide will show you how.
Plant Types
It is commonly thought that Rhododendrons only grow in a cold climate, but tropical varieties are also available that prefer more temperate climates.
Himalayan (cold climate) Rhododendrons
These are evergreen shrubs, which flower from late autumn to early spring. They have leathery leaves and are available in large and small flowered varieties. They can grow from 50cm up to 4 metres. There are over 100 varieties to choose from so see in-store for your preferred variety. It’s a good idea to buy them when they are in flower, that way you can see their colour.
Vireya (tropical climate) Rhododendrons
Vireya (tropical) Rhododendrons have glossy leaves and flower for many months. They come in unusual colours like orange, salmon and red. Some tropical varieties are reasonably cold tolerant, but almost all of them dislike frost. Here are a few varieties to consider:
- Tropic Glow: These flower 2-3 times a year and provide masses of stunning, orange trumpet-shaped flowers with a golden yellow throat. Grows about 1.5m.
- Gilded Sunrise: Flowers several times a year, producing a mass of showy flowers. Grows around 1.8-2m.
- Kisses: A compact-growing vireya which is ideal for pots or the ground, and produces a stunning display of pale pink flowers. Grows around 0.9 -1.2m.
- Cherry Glow: This is a New Zealand bred, compact, bushy variety. They produce a mass of large, flat blooms and grows best in dappled shade. Grows around 0.6m.
- Aravir: A fairly tough variety, which produces an array of delicate white flowers. Grows around 1.2m.
- Fire Plum: This variety produces a mass of deep red flowers. Grows around 2m.

Timing
Himalayan:
Best planted from March through to September.
Tropical:
Best planted from September through to March.
Location
Himalayan:
They prefer full sun in winter, and part shade in summer. These Rhododendrons grow best in cooler climates with deep soil and high rainfall. They have a very shallow root system so they can be easily grown in the garden.
Tropical:
Position in full sun to dense shade. Plants grown in shadier spots tend to be less compact than in full sun. Protection from the afternoon sun will help prevent leaves from sun damage.
Soil
Both Himalayan and tropical varieties grow best in a moist, well-drained lime-free acidic soil. Dig in plenty of compost and organic material before planting.

Watering
Rhododendrons must have plenty of water. Without enough in summer they will shut down their flower production for the following spring. However, they don’t like their feet to be sitting in water, so ensure that the soil is free draining.
Himalayan:
These varieties require plenty of water when new growth appears after flowering has finished. Deep watering is more effective than light sprinkling. In the first few years make sure they don’t fry out in summer.
Tropical:
Water each shrub deeply through the drier months.
Feeding
Himalayan:
Use a Rhododendron specific fertiliser immediately after flowering.
Tropical:
Mulch sparingly over the roots and feed with a rhododendron specific fertiliser in spring after the first flush of flowers. Making sure the fertiliser is watered in immediately.
Mulch and feed to keep the roots moist in summer. This also helps suppress weeds and reduces watering need. Keep mulch away from the plant’s stem as this can lead to rot and pests.
Maintenance
Rhododendrons can be pruned easily and very effectively. Prune young plants and old plants to create the shape you like.
When pruning, look for a growth bud on the stem that you are wanting to cut. Prune just above the bud and new growth will appear there. Look carefully on old wood to find growth buds.
Himalayan:
Pruning is best done after flowering in late spring, this gives the plants the best possible chance of flowers for the following season. In heavy frost climates prune in summer/ autumn.
Tropical:
Pinch out leggy branches after flowering to encourage shrubs to bush out.
Pests & Disease
On the whole Rhododendrons are really hardy, so if something looks amiss use ageneral insecticide or fungicide, or come and see us in-store.