Ferns Brown in Summer: Heat plus Drought in Shade Beds
Ferns brown in summer for a few simple reasons. Most outdoor ferns want shade plus even moisture, so a hot dry spell or too much sun shows up on the fronds.
The short answer
Iowa State University Extension notes ferns prefer evenly moist soil that does not dry out. Full sun may cause fronds of some species to wilt plus die. UGA Extension advises the cooler parts of the garden in summer. Water deeply, mulch the bed plus add shade.
Why do outdoor ferns turn brown in summer?
Iowa State notes intense light turns fronds yellow with shorter growth. Full sun may wilt fronds. UGA notes ferns grown outdoors in summer belong in deep shade or on the north side of a building.
| Cause | Sign | Fix |
|---|---|---|
| Dry soil | Fronds brown | Water deeply |
| Full sun | Fronds wilt plus die | Move to shade |
| Intense light | Yellow short fronds | Add shade |
| Standing water | Poor growth | Improve drainage |
Source: Iowa State University Extension plus UGA Extension.
Can ferns grow in sun?
NC State Extension notes lady fern will tolerate more sun if the soil stays moist. Christmas fern grows in part to full shade. UGA advises avoiding afternoon sun.
How should ferns be watered?
Iowa State advises watering deeply plus thoroughly. Few ferns handle standing water for long. Compost in the soil holds moisture for the fibrous roots.
How to: step by step
- Feel the soil under the fronds.
- Water deeply when it feels dry.
- Mulch the bed to hold moisture.
- Note how many hours of sun hit the bed.
- Shade ferns from afternoon sun.
- Relocate sun hit ferns in late summer.
Troubleshooting
Crisp brown fronds: dry soil. Water deeply plus mulch.
Yellow, stunted fronds: excess light. Add shade.
Long spindly fronds: too little light. Iowa State lists this sign.
For plant stress see environmental stresses on plants plus underwatering. Read mulch for cannabis. Kind Seed Co also stocks cannabis seeds.
Sources
- Growing ferns (B737), University of Georgia Extension
- Growing ferns in Iowa, Iowa State University Extension, Yard and Garden
- Athyrium filix-femina (lady fern), NC State Extension Gardener Plant Toolbox
- Polystichum acrostichoides (Christmas fern), NC State Extension Gardener Plant Toolbox
FAQ
Should brown fern fronds be cut?
Brown fronds can be trimmed. Iowa State advises removing dead portions when dividing ferns.
Can ferns grow in sun?
NC State Extension notes lady fern tolerates more sun if the soil stays moist. UGA advises against full summer sun.
When should outdoor ferns be divided?
Iowa State notes late summer or early fall is the optimum time to divide most species.
Do ferns need fertilizer?
Iowa State suggests a light fertilizer such as 10 10 10 in spring as fiddleheads emerge.
Why do my fern fronds look yellow?
Iowa State notes intense light causes fronds to turn yellow with shorter, thicker growth.
