Potted Winter Azalea Care – What To Do With Potted Azaleas In Winter
By: Tonya Barnett, (Author of FRESHCUTKY)
Azaleas are an extremely common and popular type of flowering bush. Coming in both dwarf and full sized types, these members of the Rhododendron family do well in a wide range of landscapes. Though the bushes are most commonly planted directly into their permanent location in the soil, those without the growing space may grow bright, colorful blooming plants in containers.
In fact, many cultivars of this ornamental plant grow exceptionally well when potted into containers and grown outdoors. Though most azalea plants are hardy and robust, they will require some special care to survive from one season to the next. Becoming more familiar with winterizing outdoor potted azaleas will be key to growing this plant for years to come.
Outdoor Winter Azalea Care
Before planting azaleas in containers, growers will need to learn more about their own climate and growing zone. While many cultivars of this plant are hardy to USDA zone 4, plants that are grown in containers are more susceptible to cold. Additionally, those wishing to maintain potted azaleas in winter will need to make certain to only choose pots which are able to withstand freezing conditions.
- Potted azaleas in winter will need special care to ensure that the plant does not dry out. For many, this will mean frequently checking the container and adding water as necessary. The plants should never be watered during periods of freezing weather. Next, growers will need to protect the pots from cold temperatures.
- Though the plants are naturally cold tolerant, potted azalea cold tolerance can vary greatly. Therefore, growers need to take precautions to keep the plant healthy. In winter, azalea care will require that the pot is protected from the cold. This is commonly done by sinking the pot into the ground. After the pot has been placed into the ground, many suggest covering it with several inches of mulch. Just make sure the mulch does not come into contact with the azalea plant stem, as this may cause issues with rot.
- If sinking the container into the ground is not an option, the azalea plants can be stored in a minimally heated or protected location where it will not freeze. Locations, such as near exterior walls, are often naturally warmer. These microclimates can help protect plants from extreme cold.
- Containers may also be surrounded with insulating materials such as straw bales or frost blankets to further protect the potted azalea plant. In extreme conditions, you may want to bring the potted plant indoors.
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Intro: Azaleas are flowering bushes that have impressive, showy flower blooms in the summer. Their large, colorful flowers last for weeks, and they look beautiful when cut and displayed in a vase inside. Popular in Southern-style gardens, the azalea plant is often grown as a large bush. In balcony container gardens, however, these bushes will need to be pruned – they can actually be pruned to resemble small flowering trees. There are many species, varieties and hybrids of azaleas, and you are likely to find any color and flower shape to suit your balcony garden’s conditions.
Scientific Name: Rhododendron spp.
Plant Type: Flowering shrub
Light: Part shade
Water: Water regularly, but do not overwater, as azalea plants are prone to root rot. Do not let the potting soil dry out (unless the plant is in dormancy). Gradually reduce watering about a month before the first frost.
Zone: Most azaleas do well in Zones 5 to 9, but there are evergreen varieties that can grow in cooler areas.
Temperature: Temperatures above 85 degrees will begin to damage azaleas. There are some more heat-tolerant varieties of the azalea plant. In freezing weather, some gardeners cover their azaleas with cloth to keep them warm, but because the roots of container plants are not insulated as well as those in the ground, consider bringing the containers indoors to overwinter them.
Fertilizer: Azaleas do not often need fertilizer. Add a slow-release fertilizer to the potting soil when the azaleas are dormant in between late fall or early spring.
Pests and Diseases: Generally these plants do not have problems with pests or diseases. Some problems, when they do occur, include leaf gall (cool, wet weather results in white growths and curled leaves), azalea lacebugs, spider mites, scale, etc.
Propagation: Propagate the azalea plant by taking cuttings or seeds.
Misc. Info: Flower blooms last longer in shadier spots in the balcony garden with dappled shade. This container plant does not do well in full sun (their flowers will fade), but those in full shade will grow tall and leggy. Morning sun with shade in the afternoon is best. Prune in early spring before new growth appears, and prune as the azalea blooms to encourage more flowers (these cut flowers look beautiful in a vase). Azaleas also begin to grow the next year’s flower buds after the summer blooms. Prune these flower buds, as if they will probably be killed by cold weather. There are some semi-evergreen varieties of azaleas.
Hydrating Azaleas in Winter
The University of Georgia Extension describes azalea root systems as shallow-rooted, which is a primary reason that these plants are quick to suffer water stress. Even before cold weather sets in, it’s important to keep azaleas hydrated by watering them during late summer and fall. This helps prevent drought stress before plants are subjected to winter temperatures, which can put even more environmental pressure on them.
Although natural rainfall during winter typically is sufficient to keep azaleas hydrated, keep an eye on the weather forecast. The University of California recommends watering plants two to three days ahead of a hard freeze or when numerous days of sub-freezing temperatures are expected. This helps the soil to retain and release heat to plant roots, which is even more important to protect young and newly-planted azaleas. And if cold weather is also accompanied by strong winter winds, the wind will dry the soil more quickly and exacerbate plant damage.
Modern Evergreen Azaleas
Evergreen azaleas continued development, with thousands of named cultivars registered currently with the American Azalea Society. Today's major hybrid groups are named by where hybridization occurred, the plants involved in hybridizing or who the hybridizer was. Evergreen azalea groups include Kurume, Satsuki, Kaempferi, Glenn Dale hybrids, Back Acre hybrids, Robin Hill hybrids, August Kehr hybrids, Gable hybrids, Linwood hybrids -- usually grown by florists -- and Harris hybrids. Encore hybrids are remarkable because they bloom twice a year in spring and autumn. Most varieties are grown as outdoor landscaping plants valued for their spectacular spring bloom.
How to Winterize Azaleas
Members of the rhododendron family, azaleas bloom with smaller flowers than rhododendrons. While azaleas do not continue to bloom in the winter, or even have leaves that can survive the winter as do rhododendrons, if properly winterized, azaleas can simply become dormant during the cold winter months and bloom back to life in spring.
Continue to water azaleas into the late fall, even after the plants have stopped blooming for the season. If rain remains steady throughout the fall months and keeps the soil around the azaleas moist, don’t add any additional water. The New York Chapter of the American Rhododendron Society recommends watering azaleas up until Thanksgiving.
Create mulch for the azalea. Break up pine bark, composted hardwood chips and oak leaves to create azalea mulch.
- Members of the rhododendron family, azaleas bloom with smaller flowers than rhododendrons.
- Continue to water azaleas into the late fall, even after the plants have stopped blooming for the season.
Spread the mulch to cover the ground around the base of the azalea. Use enough mulch to cover to a depth of 2 to 3 inches around the plant base ensure that the entire root ball of the plant is covered by the mulch. Do not let the mulch lie directly against the azalea plant stem.
Plant any potted azaleas into the ground for the winter months early in the fall. To plant potted azaleas, you can either transplant them from the pot into the ground or place the entire pot into the ground. Try to plant the azaleas in a place that gets little wind and only indirect sunlight and that doesn’t collect standing water.
Pile leaves and mulch around a potted azalea if you do not get the azalea planted into the ground in time. Use netting around the base of the plant to hold the leaves and mulch in place and protect the root ball during the winter months.
- Spread the mulch to cover the ground around the base of the azalea.
- Pile leaves and mulch around a potted azalea if you do not get the azalea planted into the ground in time.
The American Rhododendron Society advises against using hardwood chips directly out of a wood chipper. Fresh chips rob the nitrogen from the soil as they decompose.