Azaleas are well-known flowering shrubs for their beautiful spring blooms. Many gardeners love azaleas because of their beautiful colors and ability to grow well in shady areas. But to keep them looking their best, they need to be cared for properly, which includes fertilizing them at the right time. In this guide, we’ll talk about everything you need to know about feeding azaleas, from when to do it and what kind of fertilizer to use, so you can grow happy, healthy plants.
When is the Best Time to Fertilize Azaleas?
The ideal time to fertilize azaleas is during late winter or early spring before new growth emerges. This allows the nutrients to get absorbed by the roots and support spring growth and flowering. Specifically aim to fertilize in February or March.
Fertilizing in late fall, after the plant has gone dormant, is another option. However, spring feeding is generally preferred as it provides fuel right when the plant needs it most.
Avoid fertilizing after mid-summer. New growth this late in the season won’t harden off properly and will be susceptible to cold damage in winter.
Signs Your Azaleas Need Fertilizer
Established azaleas growing in rich, acidic, well-draining soil may not need supplemental feeding. But if your plants exhibit any of these issues, it’s a sign they could use some fertilizer:
- Small leaves and stunted new growth
- Pale or yellowing leaves
- Leaves with brown tips
- Few flowers or faded blooms
Slow release organic fertilizers can help correct these problems and get your azaleas thriving again.
How Often to Fertilize Azaleas
Azaleas are light feeders and generally only need fertilizing every 1-2 years. Annual feeding is fine for younger plants, but avoid over-fertilizing established shrubs.
Excess fertilizer can burn roots and cause buildup of salts in the soil over time. Heavy feeding can also make plants dependent, reducing their ability to draw nutrients from the soil.
Some azalea varieties, like Encore, may do better with a little more frequent feeding, about once or twice a year. But even these types don’t require heavy doses.
Best Fertilizers for Azaleas
Look for fertilizers specially formulated for azaleas, rhododendrons and other acid-loving plants. Options include:
- Organic granular fertilizers (4-3-4 or similar ratios)
- Slow release pellets
- Liquid feeds
- Compost, worm castings, alfalfa meal
Avoid high nitrogen or alkaline fertilizers which can burn plants. Also go easy on phosphorus which azaleas don’t need in large quantities.
Organic fertilizers are great because they break down slowly and feed plants slowly over time.
How to Apply Fertilizer to Azaleas
Use this easy technique when feeding azaleas:
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Sprinkle fertilizer in a circle around the outer edges of the plant.
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Extend the circle 2-3 feet beyond the drip line (the reach of the branches).
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Water thoroughly after applying to wash nutrients into the soil.
This method gets fertilizer into the widespread, shallow root zone azaleas rely on.
Follow package instructions for amounts. If the soil is dry, you should always water it before you fertilize it. Fertilizing dry soil can burn azalea roots.
The Benefits of Proper Fertilization
Feeding azaleas at the right times with the right fertilizers offers a range of benefits:
- Promotes lush green foliage
- Encourages vigorous spring growth
- Boosts flowering and flower size
- Helps plants rebound after transplanting
- Corrects nutrient deficiencies
- Keeps acid-loving azaleas happy
By following these azalea fertilization tips, you’ll have gorgeous, vibrant blooms year after year. Azaleas thrive when their needs are met. So be sure to provide good nutrition along with proper sunlight, water and pruning.
Frequently Asked Azalea Fertilization Questions
Can I use coffee grounds to fertilize azaleas?
While coffee grounds add organic matter to the soil, they don’t lower pH or provide significant nutrients. Composted grounds work better. Fresh grounds can potentially overfeed and harm plants.
Is Miracle-Gro good for azaleas?
Miracle-Gro makes fertilizers specifically formulated for azaleas, rhododendrons and other acid lovers. Used as directed, these can be effective options. But take care not to overdo it.
Should I fertilize azaleas every year?
Annual fertilization is fine for younger shrubs, but generally not necessary for mature, established azaleas. Every 2-3 years is sufficient in most cases. Let the plants’ needs guide your schedule.
When should I prune azaleas?
Prune azaleas right after flowering ends. For reblooming varieties, stop pruning 2 months before your first expected fall frost.
Feed Your Azaleas Right for the Best Blooms
Azaleas thrive when their nutritional needs are met. By fertilizing at the right time with acidic, organic feeds designed for these flowering beauties, you’ll be rewarded with lush growth and gorgeous blooms. Pay attention to your plants and let them guide you. Avoid overfeeding, and your azaleas will flourish for years to come.
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.
Best Types of Fertilizers For Azaleas
Both organic and inorganic fertilizers, formulated specifically for azaleas and other acid-loving plants, are available in granular and liquid forms as well as spikes.