To Help Azaleas Through Winter, Work Out Your Garden Micro-Climate And Plant Hardiness
Elizabeth is a Permaculture Garden Designer, Sustainability Consultant and Professional Writer, working as an advocate for positive change. She graduated from the University of St. Andrews with an MA in English and Philosophy and obtained a Diploma in Applied Permaculture Design from the Permaculture Association.
Reviewed By COLIN SKELLY
Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.
Azaleas are attractive shrubs, which come in tender or more hardy varieties.
Some are suited to growing indoors year-round, whilst others can work outside year-round in your garden.
In order to understand how to care for Azaleas in winter, you need to be clear about the hardiness of the particular variety that you are growing.
Some outdoors grown Azaleas will be fine outdoors in winter in at least some areas, but others will need to be moved to a more sheltered, warmer spot over the coldest part of the year depending on their hardiness rating.
Move tender Azaleas growing indoors, including those forced to flower for Christmas, to a cooler location with temperatures between 6-10°C.
You can then move them back when the temperature is warmer in spring.
For more details, make sure to read on.
Winter Care For Outdoor Azaleas
In order to understand whether or not you can keep an Azalea outside in your garden all year round, you need to understand hardiness ratings, as well as the conditions where you live.
Many Azaleas typically grown outside in the ground in UK gardens are H4-H6 hardy.
If an Azalea has a rating of H4, that means it can cope with outdoors conditions in an average winter in most of the UK, except for inland valleys, high altitude locations, and the far north.
In harsh winters, they may experience some damage in colder gardens.
Note that if growing in pots or containers, these plants are more vulnerable to harsh winter conditions.
If growing one of these slightly less hardy options, make sure that it is growing in a reasonably sheltered location, out of drying, cold winds and not in a frost pocket.
“I like to work out the micro-climate of a garden,” says Colin Skelly, Mater Horticulturist and Garden Consultant.
“There can be a few degrees difference between the coldest and warmest parts of the garden in both winter and summer.
“For potted Azaleas in winter, work out the most sheltered part of the garden.”
“Typically this might be under the canopy of trees and shrubs or in the lee of a garden building or house – providing shelter from both wind and frost.”
If necessary, move plants in a container to a more sheltered and protected spot, or undercover.
Even the hardiest types are more vulnerable if growing in containers.
Winter Care For Indoor Azaleas
Indoors Azaleas such as Rhododendron simsii are not suitable for outdoor cultivation.
They are often bought as pot plants and are forced to flower early, which is usually in winter.
They can be grown indoors in a cool, bright location, or in a greenhouse or conservatory.
If you wish to keep such a plant to flower again the following year, place them in a cooler location in autumn or after flowering.
Then move them back to a bright location, around 16-18°C, in the spring.
With some luck they should then flower again the following year, but if forced before purchase, will typically flower later than they did the previous year.
