Azaleas are not difficult to grow so when these shrubs, which are well-loved for their early showy blooms, do poorly, its almost always due to an environmental or nutritional imbalance. Like all species in the rhododendron family, azaleas are acid-loving plants. Maintaining the correct pH level of 4.5 to 6.0 is key to the health of your shrub.
Once established, azaleas dont need much fertilizer. Youll see better results with organic products and soil amendments like compost and mulches. If you plant your azalea in a suitable location and support its nutritional needs, youll be able to successfully grow it in your yard.
Azaleas are prized for their colorful spring blooms that emerge before the leaves unfurl. With proper fertilization, these flowering shrubs will thrive for years in the garden But when is the optimal time to feed azaleas to promote lush growth and spectacular flowers?
Azaleas belong to the genus Rhododendron and the expansive heather family. They can be deciduous or evergreen varieties. Through extensive hybridization over the years, there are now nearly 10,000 cultivated azalea varieties to choose from.
While azaleas are mainly known for their spring floral display, some new reblooming varieties like Encore azaleas flower repeatedly during the season Azaleas prefer moist, acidic, organic-rich soil and do best in part to full shade exposures. Established azalea plantings thrive with minimal care when planted in ideal conditions
Do Azaleas Need Fertilizer?
Mature azalea shrubs growing in enriched native soil usually don’t require fertilization to bloom well. The plants have an extensive network of feeder roots that forage over a wide area for nutrients.
However azaleas may occasionally exhibit signs of nutrient deficiencies especially nitrogen, iron, and phosphorus. Targeted organic fertilization remedies such problems. Routine fertilization is also recommended when planting new azaleas or to encourage stronger growth.
When to Feed Azaleas
Azaleas should only be fertilized when they are dormant, in late fall or early spring before new growth begins. Fertilizing too late in the season can stimulate tender new shoots that won’t harden off properly before winter. The optimal fertilization schedule is:
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Late fall: Apply fertilizer from mid-October to late November. This fuels root growth.
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Early spring: Fertilize in March and early April as growth resumes. This nourishes the entire plant.
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After flowering: Reblooming azaleas benefit from a feeding after the first spring flush of blooms.
Avoid fertilizing azaleas after mid-June. Always apply fertilizer to moist soil and water it in well. Never fertilize during drought conditions.
What Type of Fertilizer to Use on Azaleas
Look for fertilizers formulated especially for azaleas, rhododendrons, camellias and other acid-loving plants. Options include:
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Organic fertilizers: Derived from natural materials like fish meal, bone meal, alfalfa meal, and compost. Provide a slow, steady release of nitrogen and other nutrients.
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Synthetic fertilizers: Specially formulated for azaleas with an NPK around 10-5-4 or 10-6-8. Pick controlled-release types.
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Soil amendments: Compost, aged manure, pine needles, and leaf mold lower pH.
Avoid using lime or alkaline fertilizers which raise soil pH. Test soil pH yearly and amend as needed to maintain acidity.
How Much Fertilizer Do Azaleas Need?
Follow package directions for correct amounts to apply based on the plant’s size and fertilizer type. As a rule of thumb:
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Granular fertilizers: Spread 1⁄2 to 1 cup per mature plant.
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Liquid fertilizers: Mix according to label and apply 1-2 cups.
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Organic amendments: Apply 1-3 inches over root zones.
Apply fertilizer in a ring starting 3 feet from the center extending 2 feet beyond the drip line. This encompasses the feeder root area.
Signs Your Azaleas Need Fertilizer
Monitor azaleas regularly for any of these clues that nutrients need replenishment:
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Yellowing leaves
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Pale green or smaller leaves
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Leaf scorch or brown tips
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Excessive leaf drop
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Lackluster blooms
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Reduced growth
Target fertilization to the specific deficiency. Discontinue fertilizer if symptoms don’t improve.
Risks of Overfeeding Azaleas
While azaleas need balanced nutrition, over-fertilization can damage roots and attract pests. Signs of fertilizer burn include brown leaf margins, defoliation, and dieback.
Rely more on organic soil amendments than routine feedings. Always do a soil test before applying fertilizer to determine actual needs.
Special Considerations for Encore Azaleas
The reblooming Encore azalea series flowers from late spring until fall. Feed these varieties soon after the first bloom period ends using a controlled-release fertilizer formulated for azaleas. You can also give them a nutrient boost with liquid fertilizer during summer.
Azaleas thrive over the long-term with limited supplemental fertilization when sited properly and mulched annually. Focus on amending soil to the ideal acidic pH range. When signs of nutritional deficiencies appear, a spring feeding with specially formulated organic or synthetic plant food restores vigor. Avoid over-fertilizing azaleas, which can damage the extensive root system. With the proper fertilization schedule, azaleas will reward gardeners with years of spectacular blooms.
When to Fertilize Azaleas
Before planting an azalea, which can be done in the spring or early fall when temperatures are cool, amend the soil with plenty of organic matter.
Mulching around new and established plants with compost, shredded leaves, pine straw, or other organic materials is often sufficient to supply the nutrient needs of azaleas. However, when you want to encourage new growth, or if your plant shows signs of nutrient deficiency, the right fertilizer helps remedy the problem.
The best time to fertilize azaleas is during their dormancy between late fall and early spring. Do not fertilize after June, as that results in a spurt of new growth late in the season, which makes the plant more vulnerable to cold injury. Reblooming azaleas such as the Encore series benefit most from feeding after the first bloom.
Always apply fertilizer when the soil is moist and the fertilizer will be watered in by rain or irrigation. Never fertilize azaleas during dry weather or a drought. The lack of moisture causes fertilizer burn in the plant.
Fertilize your Encore Azaleas using these guidelines…
Follow these guidlines and watch your Encore Azaleas thrive. Download this Care Sheet
The best time to fertilize is right after spring bloom.
This spring application may be all you need, but if you live in an area with a lot of rainfall and a long growing season, you may want to make a second application in mid to late summer, making sure not to fertilize after August 1st.
When To Fertilize Azaleas
FAQ
What is the best food for azaleas?
Azaleas have low nutritional requirements compared to other shrubs. A soil amended with organic matter prior to planting followed by a mulch of compost, shredded leaves, pine straw or other organic material will usually provide sufficient nutrients for adequate growth.
When should you not fertilize azaleas?
Avoid fertilizing after June, to keep from pushing plants into active growth before the winter cold.
Is Miracle Grow good for azaleas?
A month after planting, begin feeding azaleas with Miracle-Gro® Water Soluble Azalea, Camellia, Rhododendron Plant Food. In addition to the main plant nutrients, this fertilizer also includes micronutrients such as iron, manganese, and zinc, which are vital for growing azaleas (and other acidic soil-loving plants).
How do you keep azaleas blooming all summer?
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YouTube · HortTube with Jim Putnamhttps://m.youtube.comHow to Increase Summer Flowers on Encore Azaleas – YouTubeAug 14, 2019 — and the ups and downs of the temperatures are have less and less impact. so don’t panic at all if you don’t see flowers uh in the first summer or yo…
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YouTubehttps://www.youtube.comHow and When to Prune Encore Azaleas – YouTubeMay 22, 2020 — Most azaleas in 4-5 hours full, mid-day sun will be prone to lacebugs. So there is a bit of a conflict with planting many of the remontant azaleas i…