Big, bright splashes of colour. Glorious blooms blossoming all over your garden. Dazzling bushes that can grow to tower over you – and even your home!
We’re talking about rhododendrons, of course – one of the world’s most beloved garden plants. Read ahead for everything you need to know about growing these lovely flowers in your own home garden.
Rhododendrons are a genus of at least 1,024 species of woody plants. They belong to the heath family (Ericaceae) and can be either deciduous or evergreen. They are originally from Asia, but can now be found growing wild in lowland forests in North America, particularly in the Appalachian Mountains, Pacific Northwest, and California.
These luscious blooms are the national flower of Nepal, the state tree of Sikkim and Uttarakhand in India, the state flower of both Washington State and West Virginia in the US, and the provincial flower of Jiangxi in China.
While you might see Azaleas listed as Rhododendrons, they actually make up two subgenera. They have just five anthers per flower, which differentiates them from ‘true’ Rhododendrons.
Head to your local garden centre to peruse the selection of Rhododendrons, or shop online for seeds or plants.
Here are some tips for shopping for Rhododendrons or Azaleas:
Plant your Rhododendrons in October or March/April, depending on the variety.
Follow these steps to grow Rhododendrons in your garden.
Follow these tips to care for your Rhododendrons.
Like most ericaceous plants, rhododendrons do not like the full morning sun. They prefer dappled shade in a position sheltered from the wind.
Rhododendrons prefer rainwater over tap water, and are hard to grow in dry regions. If you water your Rhododendrons with tap water, the calcium can cause too much alkalinity and lead to yellowing leaves. If you run out of rainwater, tap water will work for a month or two.
Rhododendrons prefer well-drained moist acidic soil between pH 5.0 and 6.0. Add plenty of organic material to help them thrive. If your soil is alkaline, add ericaceous compost to reduce the pH. If you have a rock garden, you will have success with Dwarf Alpine Rhododendrons.
If you plan to prune your Rhododendron, fertilise in late fall of the year prior. If you delay, you may experience leggy growth. This is because next year’s buds form on this year’s flowers, so you need to prepare them at least a year in advance. Once you are ready to prune, trim around 10 – 15 inches from the most substantial branches, but never more than 20 inches. Cut the plant back and expose the inner branches, and cut ¼ inch above the last cluster of leaves you want to keep. Rhododendrons usually have three main branches – make sure that you prune these back to different lengths so that the shrub remains natural in appearance. If you prune too heavily, you may not experience growth for a two years or more.
Planning to grow a Dwarf Rhododendron in a pot? Follow this advice.
Rhododendrons experience some common pests and diseases.
Relaxing in wooden garden chairs, admiring the fruits of your labour – nothing makes your garden look more bright and beautiful than a Rhododendron shrub. Which variety are you planning to plant this year?
Badgett, B. (2019). Rhododendron Care. [online] www.gardeningknowhow.com. Available at: https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-care.htm [Accessed 14 Nov. 2020].
Old Farmer’s Almanac (2020). Rhododendrons and Azaleas. [online] Old Farmer’s Almanac. Available at: https://www.almanac.com/plant/rhododendrons [Accessed 14 Nov. 2020].
Royal Horticultural Society (2020). Late-flowering rhododendrons / RHS Gardening. [online] www.rhs.org.uk. Available at: https://www.rhs.org.uk/plants/popular/rhododendron/late-flowering [Accessed 23 Nov. 2020].
Royal Horticultural Society (2019). Rhododendron diseases. [online] www.rhs.org.uk. Available at: https://www.rhs.org.uk/advice/profile?pid=573 [Accessed 14 Nov. 2020].
Royal Horticultural Society (2020). How to grow rhododendrons / RHS Gardening. [online] www.rhs.org.uk. Available at: https://www.rhs.org.uk/plants/popular/rhododendron/growing-guide [Accessed 14 Nov. 2020].
Wikipedia Contributors (2020). Rhododendron. [online] Wikipedia. Available at: https://en.wikipedia.org/wiki/Rhododendron [Accessed 14 Nov. 2020].
Woodie, M. (2018). How to Grow a Rhododendron in a Container. [online] Horticulture. Available at: https://www.hortmag.com/container-gardening/how-to-grow-a-rhododendron-in-a-container [Accessed 14 Nov. 2020].
Anna is the marketing and office manager for Garden Benches – a premium supplier of high-quality wooden benches and other outdoor furniture.