The bloom time is usually spring into summer, but some cultivars bloom in late winter or late summer.
The growth rate and preferred conditions of rhododendron species vary widely.
However, most prefer moist, well-draining soils, partial shade, and conservative fertilization.
The Spruce / Evgeniya Vlasova
All rhododendrons are toxic to people and pets.
Learn how to grow stunning blooming rhododendron species with this care guide.
Soil
Rhododendrons need moist, well-draining soils rich in organic matter.
The Spruce / Evgeniya Vlasova
These shrubs prefer acidic soils with a pH between 4.5 and 6.0.
Adding a layer of mulch helps with water retention.
Temperature and Humidity
Temperature ranges vary depending on the rhododendron variety.
The Spruce / Evgeniya Vlasova
Some tolerate heat and humidity, and others are cold-hardy.
Most varieties don’t like strong winds and are sensitive to temperature extremes.
emkaplin / Getty Images
Types of Rhododendrons
Most rhododendrons sold in the nursery trade today arecultivarsand hybrids.
Pinxterbloom azalea (Rhododendron periclymenoides)emkaplin / Getty Images
It can be done at any time.
Plus, some cultivars or hybrids are trademarked and propagation is prohibited.
If you have a suitable rhododendron, take these steps to propagate it from cuttings in the early fall.
Catawba rhododendronThe Spruce / Evgeniya Vlasova
Fill it with potting mix for acid-loving plants.
Place the container in a location where it gets shade in the afternoon.
Extreme winter cold might damage buds.
Pacific rhododendronThe Spruce / Evgeniya Vlasova
Take special care not to break any buds.
Common Pests & Plant Diseases
Rhododendrons are susceptible to a wide range of pests and diseases.
The healthier the plant, the better equipped it is to fend off these pests and diseases.
Pinxterbloom azaleaThe Spruce / Evgeniya Vlasova
Alternatively, treat larger infestations with aninsecticidal soapor horticultural oil, likeneem oil.
What do Rhododendron Flowers Look and Smell Like?
Rhododendron flower form and fragrance vary considerably depending on the species and cultivar.
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Colors include white, cream, orange, pink, red, and purple.
Not all rhododendron flowers are fragrant, but the ones that are can be heady, spicy or sweet.
Common Problems with Rhododendron
Rhododendron leaves turning yellow can indicate the pH levels are too high.
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Test the soil pH beforelowering the pH.
Like everything newly planted, rhododendrons need regular watering during the first season.
However, they are relatively easy-to-care-for shrubs after they establish, usually two or three years later.
Pick a site for rhododendrons with dappled sunlight and shelter from cold, drying winds.
Avoid planting in dense, compacted soils or near concrete surfaces, which can increase soil pH levels.
The pros of rhododendrons include the wide variety available, their low-maintenance care requirements and showy spring colors.
They’re also ideal for those shadier spots in your yard, and some species can provide evergreen interest.
The Rhododendron Cultivar Collection.
Guide to Poisonous Plants.
North Caroline State University Extension.
Plant Culture and Care.
The American Rhododendron Society.
