Flame Azaleas Are the Colorful Flowers You Need to Grow this Year—Here's How

The flame azalea is a native North American shrub that gets its name from its stunning reddish-orange flowers that bloom each year. Flame azalea grows best in full or partial sunlight and needs well-draining, acidic soil. Like other azalea species, all parts of the plant are toxic to humans and pets.

Flame Azalea Care

These are the main care requirements for growing flame azalea:

• Plant in well-draining soil.

• Choose a location that receives four to six hours of light daily.

• Water regularly to maintain soil moisture.

• Fertilize in the early spring or in the late winter.

Light

Between four and six hours of sunlight is ideal for flame azaleas. Although they prefer partial shade, this shrub can grow in full sun if the heat is moderate. In areas with very hot summers, choose a spot that receives some shade during the heat of the day to protect the plant from scorching.

Soil

Like other azalea species, flame azalea prefers acidic soil. Ideally, the soil should be moist but the shrub does exhibit some drought tolerance. It’s important that the soil is well-draining to prevent oversaturation and problems with root rot. Flame azalea does not grow well in heavy clay soil.

Water

In most cases, rainfall should be sufficient but supplemental watering may be needed if precipitation is infrequent. Water when the top two inches of soil feels dry to the touch.

Temperature and Humidity

Flame azalea does best with moderate-to-warm temperatures and average humidity. In very hot conditions, the shrub will not fare well and very cold temperatures can hinder bud development. Climate conditions between 60°F and 80°F during the growing season are best.

Fertilizer

When planted in humusy, acidic soil, flame azalea may not need any fertilizer. But if the soil is too alkaline or nutrient-deficient, you might choose to apply fertilizer to the azalea shrub after foliage appears in the early spring.

A well-balanced 15-15-15 fertilizer works well or you can opt for a fertilizer specifically formulated for azalea shrubs.

Types of Flame Azalea

• ‘Golden Sunset Flame’: This variety is a good pick for a landscape border because it exhibits a slightly more upright growth habit, reaching heights between 8 and 12 feet, with a spread of about 5 to 8 feet. Blooms are shades of gold, orange, and yellow.

• ‘Cherokee’: A variety that displays lighter apricot-shaded petals with yellow stamens protruding from the blossom.

• 'Calendulaceum Gold’: Expect a large and showy bloom with fully yellow petals and a light sweet scent. This variety usually stays somewhat compact, reaching about 6 feet high and 4 feet wide at maturity.

Pruning

Heavy pruning is generally not needed for flame azalea but you may prune to maintain a general shape and to remove dead or damaged branches. Prune after flowering in the summer.

Propagating Flame Azalea

Most flame azalea shrubs are purchased commercially as mature plants but you can also propagate the shrub by means of layering or cuttings. It should be noted that deciduous shrubs, like the flame azalea, can be challenging to successfully propagate by means of cuttings. Layering carries a higher chance of success; here’s how to do it:

1. During the growing season, choose a branch from the lower region of the shrub with enough length and flexibility to reach the ground. (The branch will remain attached to the parent shrub but a section of it will be buried and the end of the branch will stick up into the air.)

2. Dig a trench an inch or two deep; bend the branch to rest in the trench. Identify which section of the branch will rest in the trench and remove some of the bark from that area. Apply rooting hormone, if desired.

3. With part of the branch laying in the trench and the free end of the branch extending into the air, secure the branch to the ground with rocks, stakes, or wire. Fill in the trench with dirt.

4. Don’t disturb the branch for at least a year to allow roots to develop.

5. Once the branch has its own root system, you can cut the branch from the parent shrub and transplant the new shrub to your desired spot.
   

How to Grow Flame Azalea From Seed

Growing flame azalea from seed is relatively easy to do, but takes time—expect at least a few years to pass before you’ll see the shrub produce flowers. But if you have the patience to wait, you can grow flame azalea from seed purchased commercially or from collected seeds from existing shrubs. Here’s how to go about it:

1. Collect seed pods from the shrub once they turn brown (usually after the first frost in the fall).

2. Bring the seed pods indoors and spread them out to dry. Once the pods split open, gather the small seeds from within the pod and separate them from any plant debris.

3. Hold the seeds until winter, then sow into a seed flat filled with seed-starter potting soil. To effectively sow the seeds, moisten the flat, then scatter the seeds across the surface. Cover with a very light layer of soil and then use clear plastic wrap or a clear lid to cover the flat.

4. Place the tray in a warm location that receives bright, indirect light. Maintain soil moisture with regular misting.

5. Expect the seeds to germinate in several weeks; two to six weeks is typical. Move the seedlings within the tray to give each new plant at least two inches of clearance from the next plant.

6. Once the seedling has sprouted two pairs of leaves, transplant them to individual pots and cover with plastic. Continue to grow in a warm, bright location and provide regular watering.

7. After about two weeks, remove the plastic and transfer the pots to an outdoor location.

8. Once a full growing season has elapsed, repot the shrubs into individual one-gallon pots or transplant them into the ground during the fall, if you desire.

Common Pests & Plant Diseases

Like other types of azaleas, flame azalea shrubs are susceptible to pests like bark scale, lace bugs, and borers. Neem oil or another commercially available pest spray can be used to treat infestations.

In addition, diseases like powdery mildew, rust, fungal leaf spot, and gall can affect flame azalea. Azaleas grown in heavy shade or with insufficient spacing and air flow are most likely to be impacted by fungal diseases so it’s important to choose the correct planting location for a flame azalea.

How to Get Flame Azalea to Bloom

The flowers of a flame azalea shrub are its most distinguishing feature. The show starts with deeply colored orangey-red buds that open to reveal trumpet-shaped flowers in orange, red, or yellow with long stamens, giving the appearance of a flame. There is no flower fragrance for most flame azalea shrubs, although some varieties might have a light scent.

Bloom Months

While some azalea species bloom in early spring, flame azalea blooms in late spring and early summer, in most climates. May and June are often peak bloom months, but you might see flowers as early as March or April and as late as July.

The flame azalea will bloom for about two weeks. The shrub reliably blooms each year, assuming it’s healthy and its basic care requirements are met.

Caring for Flame Azalea After It Blooms

It’s not necessary to deadhead flame azalea but you can remove the spent flowers if you want to clean up the bush’s appearance or prevent self-seeding. Be careful not to pluck off any buds forming for next year’s growth. If you need to prune your azalea bush, after flowering is the best time to do so.

Common Problems With Flame Azalea

If you notice changes to the general appearance or foliage of a flame azalea shrub, it may be an indicator of a problem that requires correction or treatment. Here are some of the most common problems with the flame azalea:

Leaves Turning Yellow

If the foliage of a flame azalea shrub turns from a deep green hue to yellow, it’s likely a sign of chlorosis caused by iron deficiency.

An iron-deficient azalea bush is likely planted in soil that has a high pH. Test the pH of the soil and amend if necessary to ensure that the soil is alkaline. You can lower the soil pH with sulfur or iron sulfate or a fertilizer with ammonium sulfate but avoid aluminum sulfate. This additive is often used to increase soil acidity for hydrangea shrubs but azalea shrubs don’t tolerate high levels of aluminum in the soil.

Leaves Turning Brown

If you notice an entire branch with leaves turning brown during the growing season, the shrub may have been injured by cold temperatures during winter. To confirm, look for evidence of bark splitting at the base of the branch or the trunk of the shrub. This is more likely to be a problem if you’re growing flame azalea near the northern border of USDA hardiness zone 5.

Take steps to protect the shrub at the onset of the following winter. Avoid fertilizing late in the summer and reduce watering to slow growth (but give a final deep watering after the first frost). You might also consider mulching the root perimeter to insulate the shrub against cold temperatures but be careful not to crowd the base of the shrub and remove the mulch in the spring.

Frequently Asked Questions

How big does a flame azalea get?

A mature flame azalea reaches an average height between 6 and 12 feet, but the plant can grow as tall as 15 feet. Azaleas are relatively slow-growing, so it can take up to a decade for the shrub to reach its full height.

Are flame azaleas deciduous?

Flame azalea is a deciduous shrub, meaning that it will drop its leaves at the onset of winter. Deciduous azalea varieties can be more susceptible to rust and powdery mildew so be vigilant about monitoring for signs of these conditions.

Read Next: 10 Types of Azaleas for Your Flower Garden

Read the original article on The Spruce.