What’s the most welcome sight in spring? Azaleas in full bloom, of course! These loosely branched plants with elliptical leaves can add delightful color to any spring garden. Heirloom varieties can grow more than 20 feet tall, while dwarf varieties stay under three feet. The range of colors is spectacular, from white to pale pink to reds and purples. Most azaleas bloom in mid-spring (mid to late April), but some bloom earlier or later. Like their larger cousins, the rhododendrons, the azalea’s thick leaves can be evergreen or deciduous.
The best time to plant azalea shrubs is in the spring or early fall. They grow at different rates depending on the species, but most of them grow slowly. A one-gallon plant usually flowers in its first year, but it can take up to 10 years to reach its full size.
Azaleas and rhododendrons contain toxins that can be harmful to humans and animals. Eating any part of these plants can cause symptoms like an upset stomach or heart problems. In some cases, it has even led to death, particularly in grazing animals like horses.
Azalea Care
If you want to be successful in growing long-lived shrubs, you need to plant them in the right locations. They can be easy to grow in favorable conditions, but very temperamental if the conditions are not just right. The key is to have loose, well-draining soil that is somewhat acidic. In areas with dense soil, you may need to create an elevated planting area by bringing in loose, porous soil.
To plant azaleas, start by digging a hole as deep as the pot they are in and twice as wide. Then, mix in some peat moss and compost to improve the soil texture and pH. Peat moss is a naturally acidifying amendment, which azaleas need to thrive. After planting the azaleas, water them daily for the first week until they are established.
Light
Azaleas will do best if they are in a partially shady location that gets a few hours of morning sun. However, if it becomes too hot, the flowers may wilt. In colder climates, azaleas may respond better to being in full sun, while gardeners in warmer climates should give their azaleas more shade.
Soil
Azaleas thrive in acidic soil, which is why most potted nursery plants have peat moss as their planting medium. The soil should also have good drainage and fertility, as well as plenty of organic matter. Azaleas tend to do best with a natural mulch like pine bark mulch.
Water
Azaleas need water to bloom, and spring rain showers are usually enough. However, if the spring is dry, extra watering can help.
Temperature and Humidity
Azaleas’ hardiness depends on the cultivar, so it is important to be careful when choosing your plant and planting site. If it is too cold, buds may not form; if it is too hot, flowers may be damaged from over-exposure. Mildew can be a problem with azaleas; make sure they have plenty of air circulation and don’t plant them too close to other large shrubs.
Fertilizing
Azaleas need fertilizer to thrive. A 15-15-15 fertilizer with nitrogen, phosphorous, and potassium is a good choice for most azaleas. Specialized azalea fertilizers are also available and may be a better choice in some cases. Acidifying fertilizers are a good choice for azaleas growing in neutral or alkaline soils.
Fertilize your garden in late winter or early spring, but no later than the last week of March.
Types of Azalea
New varieties of azalea are constantly being bred to accommodate different growing regions. Here are some tried and true ones:
- ‘Rosy Lights’: This compact (4 to 6 feet) deciduous cold-hardy shrub blooms in late spring and features a sprightly flower in a rosy red color with hues of coral and blush. This is one of the ‘Northern Lights’ series of azalea-rhododendron hybrids. The flowers are borne in “trusses”—not as round as traditional rhododendrons but not as diffused as traditional azaleas. It is hardy in USDA zones 3 to 7.
- ‘Windbeam’: With smaller leaves and a tidy habit (3 to 4 feet), this popular cultivar features luminous pale pink flowers and olive green leaves that turn bronze in autumn. Hardy in Zones 4 to 8, it may need shelter from harsh winter winds, but it is more sun and heat tolerant than other azaleas. The spring display is stunning, beginning white and then evolving to pink with tiny red freckles on the dorsal lobes.
- Golden Lights’: The bright golden-orange blooms on this ‘Northern Lights’ cultivar offer a dramatic color for the spring landscape. Cold-hardy (USDA zones 3 to 7) and compact (3 to 6 feet) the flower trusses are flat and contain ten flowers each, in shades ranging from butter yellow to orange with salmon-pink highlights.
- ‘Fragrant Star’: The pure white flowers on this small, 3- to 4-foot mid-spring bloomer have a heady, spicy fragrance. The leaves are a pleasing bluish green. It is quite heat-tolerant but not as cold-hardy as others (zones 5 to 9), though can withstand cold temperatures as low as minus 20 degrees Fahrenheit if sheltered from harsh winds.
- ‘Gibraltar’: This popular azalea boasts frilly, faintly fragrant, bright orange flowers that emerge from crimson buds. It is of medium height (4 to 5 feet ) and relatively cold hardy (zones 5 to 8). This variety is also very mildew resistant.
Pruning
Pruning azaleas is not necessary to maintain their informal growth habit, which iswhen they look best. However,Azaleas may respond well to light pruning, which will promote fuller growth. Azaleas produce buds in the summer, so the best time to prune is shortly after the flowers fall off in late spring.
Pruning off spent flowers, or deadheading, will make the plant look neater and will cause the plant to direct its energy into creating more leaves. Be cautious while deadheading, as the buds for next year’s flowers are often located just below the current flowers. If you’re not careful, you may accidentally pinch off the future buds.
Where, when, and how to plant azaleas
Azaleas are very tough shrubs. I tell clients that they are “bullet-proof plants.” However, there are some things you can do to make them happier and healthier. Here are a few things to keep in mind from the beginning.
Where to plant azaleas
When choosing a location for an azalea, it is important to consider the amount of sunlight the spot will receive. Azaleas generally prefer partial shade or dappled sunlight, with morning sun being the best. If they get too much sun, they will struggle. If they get too little sun, the plant may be healthy, but there will not be as many flowers.
- Azaleas are great for containers, just be sure to choose a larger-sized container to allow room for their robust growth.
- Azaleas prefer moist, well-drained soil, as their shallow roots don’t like sitting in water.
- Azaleas also prefer soil that’s on the acidic side of the pH scale (pH of 4.5 to 6.0). People who have naturally acidic soil will be able to grow azaleas quite easily. However, if you have more neutral to alkaline soil, you will need to amend the soil. Aluminum sulfate, sulfur, acidic fertilizer, and iron sulfate are all commonly used to make the soil more acidic. You can also use coffee grounds, pine needle mulch, and sphagnum peat moss as more gentle forms of acidifying soil.
When to plant azaleas
The best time to plant azaleas in milder regions is spring or fall. Planting in fall is ideal because it gives the azaleas a chance to put down roots to better support the new growth and flowers in the spring.
How to plant azaleas
When planting azaleas, dig a hole that is the same depth as the container and about 2-3 times wide. The top of the root ball should be just above the ground. This will encourage the right kind of root growth. Then add compost and mulch to give them some nutrients over time.
How to water, mulch, and fertilize azaleas
Give your azaleas the following things to ensure they thrive:
How to Water Azaleas
The best way to water azaleas is to aim toward the base and avoid getting water on the leaves. This will minimize the chances of disease. The best time to water is always in the morning, giving the sun time to dry off any water that lands on the leaves.
How to Mulch Azaleas
It is best to use an acidic mulch, such as pine straw, pine bark, or chopped oak leaves, when mulching azaleas. This should be done by putting down two inches of mulch and keeping it two inches away from the trunk of the plant. This will help to deter animals from eating the plant. The mulch should be replenished every year or as needed.
How to Fertilize Azaleas
The best time to fertilize azaleas is either in the spring right after they finish flowering or in midsummer. You should use an acidic fertilizer, especially if your soil isn’t already acidic.
5 Ways to use azaleas in your garden
1. En masse
-Azaleas can make a yard more connected by “hugging” spaces together -Their mounding shape is good for shrub borders and perennial beds
2. Hedges
Azaleas that stay green all year (evergreen azaleas) make great hedges because they grow densely and keep their leaves. They also add a splash of color twice a year.
3. Foundation Plants
Azaleas make good foundation plants because they are a suitable size and shape. They also look good in shaded areas which are often found next to houses. The bright flowers stand out against any color of wall.
4. Container Specimens
Small azaleas like Double Shot are ideal for putting in pots and are excellent for brightening up patios, porches, and outdoor areas.
5. Garden Specimens
A single azalea shrub can be used to accentuate a small garden bed. The many forms and colors available make it possible to create a beautiful contrast with other plants in the garden.
How to Grow Azaleas From Seed
Azaleas can be grown either from commercially bought seeds, or from seeds that you collect from the seed pods that are seen when the flowers drop. However, this is a slow process that can take two to three years before the new shrubs flower. Because of this, seed-starting is not often attempted by those who are not professional gardeners. Another thing to be aware of is that offspring produced by seeds from hybrid shrubs may not look like the parent plant.
Azalea seeds can be collected after the first frost and dried indoors. To plant, mix azalea seeds with sand and peat moss, then moisten and place in a bright location out of direct sunlight. Most azalea seeds will germinate within two to six weeks.
(1) When the seedlings have two sets of leaves, transplant them into small pots. (2) Cover the pots with plastic and keep them in a bright location. (3) Within a week or two, remove the plastic. (4) Move the pots outdoors as the weather gets warmer. (5) After the first growing season, pot the plants up into larger pots or transplant them into the garden.
