Azaleas Make Excellent Container Plants – Just Be Sure To Get These Factors Right
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.
IN THIS GUIDE
Azalea is a subsection within the Rhododendron genus which provides plenty of really attractive evergreen or deciduous shrubs for your garden.
Though Azaleas were once categorised as a different species, they are now placed alongside other Rhododendrons within the same genus.
They can be an excellent choice if you are looking for a flowering shrub for your garden.
However, growing Azaleas requires acidic soil, so if you have alkaline soil, you might wonder whether you can grow azaleas in pots.
You might also wonder if you can grow Azaleas in pots if you don’t have a big garden.
Are Azaleas Suitable For Pots?
The good news is that many different types of Azalea make excellent container plants.
Some hardier types with more compact growth habits make ideal plants for an outdoor container garden and some tender types can even be grown indoors as houseplants.
When deciding which Azalea to grow in a container, it is important to consider the growth habit of the particular cultivar you are considering, and the size to which it will eventually be expected to grow.
Smaller options are generally best for container cultivation.
Choosing A Container
When choosing a container for Azaleas, make sure that the pot is large enough to accommodate the rootball with just a little space around each side.
Remember, a container that is too small will limit growth.
However, Azaleas like reasonably free-draining conditions, so it is important to choose a container that is not too large, as this could contribute to water-logging.
You should also make sure that the container you choose has adequate drainage holes at the base.
Container Compost
Azaleas typically require an acidic growing medium and they thrive in a pH between 5 and 6.
Create or purchase a peat-free, ericaceous compost if you would like to provide the optimal conditions for a potted Azalea.
Potting Up Azalea
When potting up an Azalea, make sure that the rootball sits close to the surface of the soil as these are shallow-rooted plants.
Ensure that the plant is at the same depth in its new container that it was in its previous pot.
Place some of your ericaceous growing medium in the base of the new container.
Gently place the plant into the pot, making sure that the root ball has a little space all around.
Fill in more of your growing medium around the sides, firming it in place gently, making sure that there are no air pockets.
Water it in well, allowing excess water to drain away.
Finally, it is best to mulch the top of the pot or other container with an ericaceous mulch, to maintain high humus and fertility, and replenish nutrients in the container over time.
A mulch will also help maintain pH levels and reduce moisture loss, helping to keep the medium moist.
How Many Can You Plant Per Pot?
Typically, you will plant a single Azalea in one pot since most of these shrubs will take up the space on their own.
However, you might also consider choosing a larger container and planting a small and compact Azalea alongside other acid-loving plants, such as heathers.
Potted Azalea Care
How precisely you need to care for Azaleas in containers throughout the year will depend on which cultivars you are growing, how hardy or tender they are – and where exactly they are grown.
Where To Grow
Outdoor potted Azaleas should be positioned in a sheltered location, in full sun or partial or dappled shade.
Indoors, tender Azaleas should be placed in a room with good ventilation, with dappled or indirect light.
Ideally, they should be kept in a room where temperatures remain between around 16-18°C.
Watering
The growing medium in the pots for Azaleas, indoors or out, should be kept moist but not allowed to become drenched or waterlogged.
Try to use rainwater to water your Azaleas where possible.
You may be able to use tap water, but if your tap water is alkaline, this will not be ideal for these acid-loving shrubs.
“A rule of thumb that I use is, if the kettle where you are growing has limescale then you have hard water (alkaline), so avoid watering your ericaceous plants with tap water,” says Horticultural Consultant Colin Skelly.
Feeding
Azaleas growing in containers outside will benefit from the addition or replenishment of an acidic mulch of conifer bark chippings or leaf mould each spring.
It can also be a good idea to feed weekly through spring and summer with a weekly organic, ericaceous fertiliser.
Houseplant Azaleas will also benefit from an ericaceous mulch on the top of the container each spring, or from completely repotting in the spring with a new, fertile growing medium if the growth seems poor or you are dealing with an Azalea forced to flower in winter.
A weak liquid feed of black tea can be good for Azaleas, and can help increase the acidity of the compost.
It should also help to encourage repeat flowering the following year.
Feed weekly while the plant is in active growth.
Deadheading & Pruning
Azaleas will not usually require much pruning at all, but it is a good idea to consider deadheading, as this can often encourage these shrubs to bloom for longer, and can also help to keep the plant looking good.
Deciduous Azaleas can also respond well to a hard cutting back on occasion.
Winter
Make sure that you know the hardiness rating of the Azalea you are growing.
Some outdoor Azaleas will be fine outside year round at least in some areas, but others will need to be moved to a more sheltered, warmer spot over the coldest part of the year.
This makes it ideal for growing these varieties in containers.
When growing Azaleas indoors, to encourage them to flower once more the following year, it is best to move them to a cooler location in Autumn.
Many Azaleas are not too difficult to grow in pots and can make great container plants, but make sure that you provide the right growing conditions for these shrubs to thrive.
