This One Trick Is the Key to Healthy Azaleas All Season Long, According to Gardeners

• Azaleas should be planted in early spring or early fall before extreme temperatures set in.
• Plant azaleas similarly to other shrubs and thrive in partial to full sun locations.
• ‘Northern Lights’ is one of the hardiest varieties, though most azaleas are low-maintenance and easygoing.

Beloved for their showy spring blooms and low-maintenance nature, azaleas make an excellent addition to any garden. However, knowing when and how to plant them correctly is key to giving them a strong start.

So, when are the best times to plant azaleas? Are there any important things to know about how to plant them properly? For answers to these questions and more, we consulted a gardening expert for insight.

When to Plant Azaleas

Tammy Sons, founder and CEO of TN Nursery, says that the best time to plant azaleas is when temperatures are mild in spring and fall. These cool conditions give the shrub time to establish a robust root system.

Typically, early spring (late March to early April) and early fall (mid-September to early October) are ideal, as the plant will have a few months of moderate weather before extreme temperatures set in.

However, the specific dates may vary depending on your region, so be sure to research the best time to plant azaleas for your growing zone. Avoid planting azaleas in the summer or winter, as extreme weather conditions can damage the developing roots and foliage.

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How to Plant Azaleas

Planting azaleas is straightforward and similar to planting other small shrubs and perennials. First, choose a location. Azaleas thrive in partial to full sun, although in high-heat climates, a partially shaded location is usually best to protect the flowers from intense afternoon heat.

They also require loose, well-drained acidic soil. They don’t tolerate dry soil well, so choosing a location that retains water and isn’t too sandy is key.

Given these factors, locate an area in your garden where the azalea will likely do well. If needed, amend the soil ahead of time with peat moss or sulfur to make it more acidic.

When you’re ready to plant, Sons recommends digging a hole approximately twice the size of the shrub’s root ball while maintaining even depth. Then, blend the soil you have removed with organic matter to improve drainage further and help the roots establish.

Loosen the shrub’s root ball gently and plant it in the hole, backfilling with the soil mixture. Pat the soil down firmly and water well. Azaleas benefit from light mulching with natural pine mulch to help retain moisture (and increase soil acidity). 

Newly transplanted shrubs are especially susceptible to drying out, so keeping them well-watered during the first growing season is essential. However, azaleas don’t like sitting in wet soil. Keep the soil evenly moist, not soaking, to keep your shrub happy and healthy.

Hardiest Types of Azaleas

Azaleas are generally considered to be low-maintenance, easy-going perennials once established. However, certain varieties are known for being exceptionally hardy.

Sons says the ‘Northern Lights’ hybrids are among the best for cold-hardiness because they maintain their health during cold winters. 

The ‘Northern Lights’ is a series of azalea-rhododendron hybrids developed by the University of Minnesota. Every hybrid in the series can withstand temperatures as low as -30 degrees Fahrenheit without sustaining significant damage. Hybrids in this series include:

• ‘Northern Lights’: The series’ original hybrid sports pink flowers and can grow up to 8 feet tall.
• ‘Rosy Lights’: A compact hybrid offering deeper pink flowers. It is known for being a prolific bloomer, growing up to 5 feet tall.
• ‘Golden Lights’: Has bright orange-yellow flowers and grows 4 to 6 feet tall. It is known for having the best mildew resistance of any hybrid in the series.
• ‘Orchid Lights’: Known for being the hardiest of the series, Orchid Lights has small, light purplish-pink flowers and a compact growth habit. At maturity, it will reach just 3 feet tall.
• ‘Lemon Lights’: Offers medium-sized buttery yellow flowers and grows up to 6 feet tall. 
• ‘Northern Hi-Lights’: A unique two-toned hybrid offering pale yellow flowers with a spot of deeper yellow. It reaches 4 to 6 feet tall at maturity. 
• ‘White Lights’: Sports delicate white flowers with pink highlights. This hybrid grows up to 5 feet tall and is known for being the second hardiest in the series behind “Orchid Lights.”