Azalea Prone to Iron Deficiency: How to Protect
Rhododendron simsii
Iron deficiency, commonly known as iron chlorosis, is a nutrient deficiency disorder where plants cannot access sufficient iron from the soil. While iron is typically abundant in soil, various soil conditions can limit plant uptake, resulting in characteristic yellowing of leaves while veins remain green.
ð Symptoms
- âĒ Yellowing of leaves (chlorosis) while veins remain green - most obvious symptom
- âĒ Yellowing starts at the tips of new growth and progresses to older leaves
- âĒ Severe cases show yellowing even in leaf veins
- âĒ Leaves may turn completely white in extreme deficiency
- âĒ Leaf edges may scorch and turn brown as cells die
- âĒ Poor overall growth and stunted development
- âĒ Leaf loss in advanced stages
â Possible Causes
- â High soil pH (above 7.0) restricting iron availability
- â Compacted or waterlogged soil limiting root oxygen
- â Clay soil lacking organic matter
- â Excessive phosphorus blocking iron uptake
- â Poor drainage and saturated soil conditions
- â Cold soil temperatures reducing iron absorption
- â Alkaline soil conditions
ð Treatment
Quick Fixes
Step 1
Apply chelated iron (FeEDDHA or FeEDTA) directly to soil around root zone
Step 2
Water thoroughly after application to activate chelates
Step 3
Spray foliage with ferrous sulfate solution (1-2 tablespoons per gallon) for rapid greening
Step 4
Repeat foliar application every 7-10 days until symptoms improve
Step 5
Follow up with soil application for sustained results
Organic Treatment
Step 1
Add 2-3 inches of organic compost around the plant base
Step 2
Mix composted manure into the top 6 inches of soil
Step 3
Apply iron-rich organic amendments like blood meal or fish emulsion
Step 4
Add peat moss to acidify soil and improve iron availability
Step 5
Mulch with organic material to maintain soil moisture and acidity
ðĄïļ Prevention
- â Choose appropriate soil for plant species (avoid lime soils for acid-loving plants)
- â Add well-rotted manure or compost to improve soil structure
- â Ensure proper drainage to prevent waterlogging
- â Aerate compacted areas around plant base
- â Reduce watering in poorly draining areas
- â Control soil pH through amendments
- â Optimize phosphorus fertilization to prevent excess
- â Test soil regularly to monitor nutrient levels
ðą Care Guide: Azalea
ð§ How to Water
Keep the soil consistently moist, but avoid waterlogging. Check the soil moisture with your finger before watering again. Use chlorine-free water if possible.
âïļ Lighting
Prefers bright indirect light. Avoid strong direct sun, especially during the hottest hours of the day, as it can burn the leaves and flowers. Indoors, place near a curtained window or in a spot with filtered light.
ðŠī Ideal Soil
Use a well-draining, acidic substrate rich in organic matter. A mix for azaleas or rhododendrons is ideal, or a combination of peat moss, pine bark, and coarse sand.