Fern diseases are usually uncommon. They may be caused by bacteria, fungi or viruses.

Symptoms of disease in ferns include:

  • Rots - plants become slimy due to tissue disintegration
  • Leaf spots - small to large spots on fronds or stipes. May be surrounded by a halo of lighter coloured tissue
  • Blights - causes death in young fronds, usually while they are uncurling
  • Blotches - large, irregularly shaped spots
  • Moulds and mildews - fungal threads can be seen. Usually a grey fluffy layer.
  • Wilting - young fronds wilt, and rhizomes die back from the tip. Usually indicates a problem with root growth or water supply


The most common fern diseases are damping off, fungal/bacterial leaf spots and root, crown and stem rots.

The best way to avoid these diseases is to make sure your ferns are healthy and well fed, not overcrowded, with appropriate levels of moisture (not waterlogged).

Treatment involves quarantining the plant, removing the affected parts and destroying them. An ounce of prevention is worth a pound of cure! An antifungal agent can may be used to treat fungal infections, but as with other chemicals, care must be taken to avoid damage to the plant from too high a concentration.

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