Java Fern Windeløv

'Windeløv' is one of the best-known cultivated forms of Java fern (Microsorum pteropus); it is named after Holger Windeløv, the Danish plant grower who popularized it. The tips of the lance-shaped leaves fork repeatedly into small, curly lobes, creating a lace-like look. The plant reaches 15–20 cm in height; it stays somewhat smaller and denser than regular Java fern.

In terms of care it is the same as the species itself: because of its bitter taste most fish leave it alone, and it can be used safely in goldfish, cichlid and beginner tanks.

Never bury the rhizome; a buried rhizome rots.

• Tie it to wood or rock with cotton thread or fishing line, or fix it with gel glue.
• The brown, hairy roots grip the surface in a few weeks.
• Place it in the midground, on wood branches, behind rocks and in corners.

• Light: low to medium. In strong light the leaves may develop brown spots.
• CO₂: not required.
• Fertilizer: liquid fertilizer and fish waste are enough; with potassium deficiency, brown spots form on the leaves.
• Trimming: cut old, spotted leaves at the base of the stalk.

Daughter plantlets form on old leaves, especially on the tip lobes. Once they have produced a few leaves and roots, they can be detached and tied elsewhere. The rhizome can also be propagated by dividing it so that each piece keeps a few leaves.

• Blackening or brown-spotted leaves: too much light, nutrient (especially potassium) deficiency or a buried rhizome.
• Melting: with sudden changes in water parameters, the leaves may darken; if the rhizome is healthy it will sprout again.
• Slow growth: this is natural; do not move the plant around often.