Indoor azaleas can provide an abundance of colorful flowers in the home in the Spring and only require bright indirect light and relatively cool temperatures.
The care for indoor azaleas is relatively simple although there are a few things you need to know to ensure that your plant remains healthy…
| Care Information | Indoor Azaleas |
|---|---|
| Room Temperature Range: | Cool temperatures of 13-16°C (55-61°F) in the winter and temperatures of up to 22 °C (71 °F) in the Summer |
| Watering: | Water as frequently as required to keep the soil moist (not not saturated). Mist the plant when in bloom to increase humidity. Use rain water as this has the preferred acidity whereas tap water may be neutral or alkaline. |
| Potting Soil: | Ericaceous (acidic) compost (azaleas require a soil pH of 4-6) is available from garden centers and online. |
| Fertilizing: | Fertilize in the Spring with slow-release granular fertilizer. |
| Pruning: | The most common indoor varieties do not require annual pruning and tend to maintain a compact shape. |
| Sunlight: | Bright Indirect Sun is best. Too much sun will burn the tender leaves. |
| Common Problems: | Root rot can occur in pots without proper drainage. Leaf drop is common in houses with high temperatures. |
| Best species for Indoors: | Indica Azaleas (commonly known as evergreen azaleas) cope well with low light and relatively warm Winter temperatures in the home. |
| Flowering time | Spring (March/April). |
Keep reading to learn all the best practices when caring for indoor azaleas and how to avoid the most common problems…
Soil For Indoor Azalea
Indoor azaleas require potting soil that has the following attributes:
- Well-draining, porous structure allows excess water to drain away from the roots and allows for root respiration.
- Moisture retaining soil so the roots can draw upon the moisture as and when they need to.
- Acidic soil with a pH of 4-6
- Soil with a high organic content for nutrients
For indoor azaleas, there are commercial potting mixes available in garden centers and online that crucially are within the optimal range of acidity for azaleas. Azaleas will not grow in soils that are pH neutral or alkaline as they won’t be able to access nutrients so formulated potting mixes are a good idea to ensure the soil has the right level of acidity for azaleas.
Alternatively, you can create your own potting mix with ingredients such as pine needles, leaf mold (oak and beech leaf are ideal) peat moss, and garden compost.
All these materials are acidic and contribute to aerated porous soil which retains moisture but allows excess water to drain away so that the soil does not become boggy which promotes the conditions for root rot.
An even mix of all these materials will provide the right structure, acidity, and balance of nutrients required by indoor azaleas. Read my article to learn how to create the optimal potting mix for azaleas.
I would recommend a layer of gravel at the bottom of the pot to keep the drainage holes at the base clear of compacted soil so that water can escape freely which will help to prevent the fungal disease root rot.
Watering Indoors
Azaleas are shallow-rooted plants and require moist soil, therefore they are often one of the first plants in your home or garden to show the symptoms of drought at the hottest times of the year.
The key to keeping indoor azaleas healthy is to water the plant with a generous soak as frequently as required to keep the soil moist.
In hot or dry climates in the home, you will have to water the azalea more frequently, often as much as twice or three times per week with the occasional mist to increase the humidity.
In cooler houses and at cooler times of year the azalea may only require watering once per week to keep the soil moisture at the right balance.
Indoor azaleas of the variety indica (common name: evergreen azaleas is the most common species of azaleas sold in garden centers and florists) only require bright indirect light which should help to regulate the soil’s moisture. If the azalea is in any direct light you will need to water the indoor azalea more frequently.
Overwatering is easily avoided if you have a good indoor azalea potting mix, a layer of gravel at the base of the pot, and a pot with drainage holes in the base.
Drought is always a bigger risk factor with indoor azaleas, however, if the azalea looks as though it is wilting, even with regular watering then the problem may be root rot. Read my guide to problems with azaleas in pots for more information.
Important Tip: If possible, water your indoor azalea with rainwater. Azalea requires acidic soil for the roots to uptake nutrients and prefer rainwater as it is slightly acidic whereas tap water tends to be neutral or even alkaline which can be to the determent of your azalea.
Avoiding drought is imperative, so watering occasionally with tap water will not do any harm but consistently watering with tap water for extended periods is not advised.
Fertilizing Indoor Azaleas
Fertilizing Indoor azaleas is important for several reasons:
- Potted plants naturally have less access to nutrients so the soil requires enriching every year.
- Fertilizing azaleas helps to keep them healthy and disease-resistant.
- Fertilizing (in the Spring) helps to support new growth and blooms.
The best time to fertilize azaleas is in the Spring (March/April) to stimulate new growth and encourage blooms. Do not fertilize later in the growing season as this tends to encourage growth at the expense of flowers.
It is important to use a fertilizer that is specifically made for azaleas (such as this miracle grow fertilizer) as it is formulated with the correct balance of nutrients for azaleas. Azalea’s tender leaves and roots can be quite vulnerable when exposed to fertilizer that is too strong for them.
Specific fertilizers (also suitable for rhododendrons and camellias) are able to contribute to the acidity of the soil so that the right soil pH can be maintained over time with minimal effort. This ensures that the azalea roots are able to uptake all the nutrients to remain healthy and live for a very long time.
Room Temperature and Sunlight
Indoor azaleas (azalea idicum) require a fairly cool temperature range of 13-16°C (55-61°F) in the winter and temperatures of up to 22 °C (71 °F) in the summer months.
Place them out of direct light and it is important to keep the plant away from draughts, air conditioning currents, heating, radiators, and forced air.
A porch, hallway, or any cool room with enough light will be ideal. Direct sunlight will likely increase the rate at which the azalea soil dries out which leads to wilting leaves, flowers, and stunted growth.
Azalea idcum also has tender leaves (as is common with azaleas and rhododendrons) and can be susceptible to sun damage with too much light.
Too much shade in a room can reduce flowering so aim for bright indirect light for best results.
Choosing the Right Pots or Containers
Indoor azaleas require soil to hold moisture and have a porous structure that allows excess water to drain away from the roots to prevent root rot.
Therefore the pots for indoor azaleas require drainage holes in the base to allow the water to escape so the soil does not become boggy and thereby increase the risk of fungal disease. A layer of grit at the bottom of the pot can help keep the drainage holes free from compacted soil which can prevent water from escaping.
Choose a pot size that can accommodate the root ball comfortably but notably indoors azaleas do not mind their roots becoming somewhat pot-bound as long as they receive enough water and an application of fertilizer in the Spring.
Common Problems:
Leaf drop
The most common problem with indoor azaleas is leaf drop. This tends to happen as a sign of stress in houses with high temperatures or dramatically fluctuating temperatures from day to night. This is particularly common in Winter when the heating is turned on for the cold night.
Keep the azaleas in a room where the temperature is more consistent and you should not have any problems. The azalea should recover by the next growing season.
There are a few other causes of leaf drop which you can learn the solution for in my article why are my indoor azalea leaves falling off.
Wilting Leaves and Flowers
Wilting leaves are usually caused by drought although it could be that the soil is boggy because the azalea pot does not have enough drainage at the base.
Drought is a threat to indoor azaleas and the first signs of stress are wilting leaves and flowers with the leaves curling up. This is easily treated with generous watering and the plant should recover in as little as 24 hours.
Remember azaleas require the soil to be moist so always water the plant as frequently as required to maintain the soil moisture.
If the problem is root rot (wilting appearance with brown patches on the leaves) then you need to plant the azalea in new, well-draining compost and ensure that the pot has drainage holes in the base.
Indoor azaleas do not always recover from root rot but snipping off the affect roots (yellow with a rotten appearance) with a sterile pair of pruners will help.
Yellow Leaves
Leaves that are turning yellow are often a sign of stress because of:
- Soil conditions that are not in the ideal range of acidity (pH 4-6)
- Lack of fertilizer application in the springtime
It is important to plant azaleas in prepared acidic compost which is available in stores or online or you can compose it yourself with peat moss, compost, and leaf mold mix.
Water with rain water and use a fertilizer specifically for plants that require acidic conditions and the azalea should recover, although it may take some time.
As access to nutrients is limited in a pot, fertilizing in the spring is important to provide the azalea with the right balance of nutrients to keep the plant healthy.
Yellow leaves can green up in a matter of two weeks after an application of fertilizer. For more information read my article on solutions for azaleas with yellow leaves.