Boston Fern with Sunburn (Sun Scorch): Prevention & Cure
Nephrolepis exaltata
Sunburn or sun scorch is an environmental condition that occurs when plants are exposed to intense, direct sunlight beyond their tolerance level. This causes the breakdown of chlorophyll in the leaves, resulting in bleached, dried, and damaged foliage. The damage can happen rapidly, sometimes within just a few hours of exposure.
ð Symptoms
- âĒ Pale, bleached, or washed-out white areas on leaves
- âĒ Affected areas turn yellow, then brown, and become brittle
- âĒ Damage appears primarily on top leaves or sun-exposed surfaces
- âĒ Leaf edges become completely dry and crispy
- âĒ Underlying leaves remain unaffected
- âĒ Rapid onset of symptoms (within hours)
â Possible Causes
- â Abrupt exposure to bright, direct sunlight
- â Moving plants from low-light to high-light environments too quickly
- â Intense sun combined with dry soil conditions
- â Hot temperatures and high winds increasing water loss
- â Lack of gradual acclimation (hardening off)
- â Water droplets on leaves acting as magnifying lenses in bright sun
ð Treatment
Quick Fixes
Step 1
Immediately provide shade using umbrellas, cardboard, or shade cloth during hottest hours (10am-4pm)
Step 2
Give a deep watering in the early morning to reduce plant stress
Step 3
Remove completely scorched leaves to prevent rot
Step 4
Monitor daily and adjust shade as needed
Organic Treatment
Step 1
Move the plant to a shaded area or use shade cloth to block direct afternoon sun
Step 2
Prune away severely damaged leaves and stems to prevent disease
Step 3
Apply a thick layer of organic mulch (2-3 inches) around the base to retain soil moisture
Step 4
Deep water in the morning to help the plant recover from stress
Step 5
Wait one week, then apply liquid seaweed fertilizer to speed healing
Step 6
Gradually reintroduce the plant to sunlight over 2-3 weeks
ðĄïļ Prevention
- â Gradually acclimate plants to bright sun over 2-3 weeks (hardening off)
- â Start with full shade, then introduce 1-2 hours of morning sun
- â Keep plants out of direct sunlight during extremely hot days
- â Use sheer curtains or shade cloth to filter intense light
- â Water adequately, especially on hot and windy days
- â Water in morning or evening to avoid droplets during peak sun
- â Apply organic mulch to conserve soil moisture and reduce temperature
- â Provide temporary shading on extremely hot days
ðą Care Guide: Boston Fern
ð§ How to Water
Water when the top inch of soil feels dry, usually 2-3 times per week. Keep soil consistently moist but never soggy. Reduce watering in winter when growth slows. Use room temperature water to avoid shocking the roots.
âïļ Lighting
Prefers bright, indirect light but can tolerate low light conditions. Avoid direct sunlight which can scorch the delicate fronds. East-facing windows or filtered light from south/west windows work best. Insufficient light may cause yellowing leaves.
ðŠī Ideal Soil
Use well-draining, rich organic soil with a pH of 5.5-6.5. A peat-based potting mix with added perlite works well. The soil should retain moisture while allowing excess water to drain freely.