Whisk Fern
Psilotum nudum
A primitive fern relative with no true roots or leaves: upright forking green stems do the photosynthesis, with tiny scale-like appendages and yellow trilobed spore structures. Grow it in an airy orchid-style mix with high humidity.
Light
Bright Indirect
Water
Moderate
Difficulty
Moderate
Humidity
High
Pet Warning
Contains psilotoxin, which can cause mild to moderate digestive distress and irritation if ingested by pets or humans.
Care Notes
Light
Bright, indirect light supports the best growth. Lower light slows it further. Direct afternoon sun can yellow or brown stems.
Water
Keep moisture even. Water when the top half-inch of mix feels dry. Drainage holes matter; waterlogged media rot the rhizomes.
Soil
Skip heavy potting soil. Use an orchid-style blend of bark, perlite, and a little peat or coco coir so air reaches the rhizomes.
Humidity & Temperature
Keep humidity above 60% with a humidifier, pebble tray, or plant grouping. Aim for 65-85°F and protect from cold drafts and temps below 50°F. Water less and pause fertilizer in fall and winter.
Common Issues
Stem dieback often means underwatering or dry air. Mushy bases usually mean overwatering or a mix that is too dense.
In-Depth Care & Growth
Feeding & Soil
Fertilizer
Balanced liquid fertilizer (10-10-10) diluted to half-strength
Soil
Coarse, airy mix of orchid bark, perlite, and peat moss
Physical Attributes
Mature Size
8-24 inches tall
Growth Rate
Slow
Propagation
Rhizome division or spore sowing
Common Varieties
Usually available as the straight species; no common commercial cultivars.
Bright green wiry stems that fork repeatedly into a whisk-like shape, with tiny scale-like appendages instead of true leaves.