Oglesby Plants International


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Nephrolepis is the most widely grown genus of tropical ferns. Nephrolepis exaltata bostoniensis, the Boston fern, is the most popular and is usually grown in hanging baskets.


Water-holding capacity and good drainage are essential. Ferns do not tolerate ‘wet feet’. Use a blend of peat with perlite, bark or other materials for good drainage. Adjust pH between 5.0 and 6.0.


Ferns do well with constant feed using 20-20-20 or 20-10-20 at 125 to 175ppm. Add a source for Sulfur occasionally such as magnesium sulfate. Be sure to leach regularly to prevent salt build-up. Keep EC below 1.5. If applying liquid feed to the foliage, be sure to rinse off afterwards. When incorporating dry fertilizer in the medium, do not include extra trace element blends.


Boston fern should be grown under 1500 to 3000 foot-candles. If growing in warm climates under shade cloth, use 50 to 80% shade. Frond length will increase with shade level. The more upright varieties, such as ‘Emerald Queen’, are often grown under much brighter light ranging from 50% shade to full sun.


While ferns will tolerate great extremes of temperatures, optimal growth occurs between 70° and 90°F. Temperatures below 60° will significantly slow growth.


As Botrytis is the most common disease problem in Boston fern, drip irrigation will minimize the potential for infection. Botrytis is most active under low temperatures and high humidity. Rhizoctonia and Pythium may also challenge the fern grower. Rhizoctonia can be prevented by keeping the foliage as dry as possible. Providing good air circulation should help minimize the potential for both Botrytis and Rhizoctonia. Pythium is often a result of extreme fluctuations of moisture levels in the growing medium or injury to the roots due to excessive salts.

Ferns do not host mites. Scale and mealybugs are rarely encountered under good growing conditions. Thrips can be a problem. Worms (larvae of Lepidoptera) are the most prevalent problem. Some growers have experienced resistance to Bacillus thuringiensis.

Copper compounds and mancozeb may cause phytotoxicity.

This text is a recommendation only; it is not an endorsement of any products or acceptance of any liability as a result of usage.