Nephrolepis exaltata 'Boston'

Origins and history of Nephrolepis exaltata 'Boston'

The arching Boston fern became known after a distinctive plant was spotted in a shipment sent from Philadelphia to Boston in 1894. It was propagated and soon grown in homes and conservatories.

Across tropical and subtropical America, Nephrolepis exaltata grows in damp forests, swamps and floodplains. It roots in soil and also grows on trees and palms.

Growing Nephrolepis exaltata 'Boston' at home

• Placement and light: Hang or raise the plant where its fronds can fall clear of walls and busy walkways. Give it bright, filtered light. Let the plant adjust gradually to direct morning sun.
• Watering: Feel the top of the potting mix. Water when the surface starts to dry but the mix still feels cool and slightly moist deeper in the basket. Pour slowly until the root ball is evenly wet and water leaves the drainage holes.
• Humidity and warmth: Humid room air helps the long fronds keep their leaflets. Place the basket in a warm part of the room, clear of radiators, cold draughts and air-conditioning outlets.
• Container and potting mix: Make sure the basket drains freely and fill it with a loose mix that remains lightly moist. Keep the crown level with the surface of the potting mix after repotting.
• Feeding: While fresh fronds are forming, feed with a balanced liquid houseplant fertiliser. Use the lowest dose on the label and feed as often as instructed. Use plain water between feeds. Stop feeding when new growth slows.
• Pruning and runners: Cut fully dry fronds close to the base and leave green curled shoots to open. Trim or guide the runners as they extend beyond the basket, or plant rooted runners in separate pots.
• Repotting and propagation: Choose a basket one size larger when roots crowd the current one or the crown begins to lift. If the mix has become dense or no longer absorbs water evenly while the roots still have room, replace the mix and reuse the basket. Each division should already have firm roots and several green fronds. Rooted runners can go into separate pots.

Troubleshooting Nephrolepis exaltata 'Boston'

• The whole plant droops and the pot feels light: The root ball has dried out. Wet the mix in stages until it is evenly moist, let the basket drain and check the potting mix more often.
• Brittle brown tips and falling leaflets: Check the moisture before adding water. If the mix is dry, water slowly until the root ball is evenly moist. If it is still damp, move the basket away from heated air or increase the room humidity. A chalky deposit on the potting mix or pot can signal excess salts. Flush the mix with plain water and let the basket drain.
• New fronds are thin, pale or have fewer leaflets: Check how much light reaches the plant. Move it into brighter filtered light when the position is dim. If the location is already bright, check the potting mix. If it stays wet for too long, let the surface begin to dry and make sure the drainage holes are clear. If it dries out completely, water more consistently. Wait for healthier new growth before feeding again.
• Several fronds yellow while the pot stays wet: Old, dense potting mix or blocked drainage can damage the roots. Lift the plant and use clean scissors to remove roots that feel soft, mushy or collapsed, or that smell sour. Stop at firm tissue, discard the rotten pieces and old mix, then repot in fresh, loose potting mix.
• Sticky fronds, fine pale speckles, webbing or white clusters: Scale insects, spider mites or mealybugs may be feeding on the plant. Move the basket away from other plants, rinse the foliage and identify the pest. Choose a treatment labelled for the identified pest and suitable for indoor ferns. Follow the dose and timing on the label.

Nephrolepis exaltata ‘Boston’ is non-toxic to cats and dogs

• This plant is non-toxic to cats and dogs.
• Its effects on people are unclear, so keep it away from young children who may chew it.
• Eating a large amount can still cause an upset stomach. Seek medical or veterinary advice if symptoms continue.

Nephrolepis exaltata: where the name comes from

Greek nephros, kidney, and lepis, scale, form Nephrolepis and refer to the small kidney-shaped coverings over the spore-bearing patches. Exaltata means elevated or very tall.

Heinrich Wilhelm Schott established the genus Nephrolepis in 1834 in Genera Filicum (Vienna), plate 3.

Carl Linnaeus first described it as Polypodium exaltatum in 1759 in Systema Naturae, tenth edition, volume 2, page 1326. Heinrich Wilhelm Schott later placed it in Nephrolepis as Nephrolepis exaltata in 1834 in Genera Filicum (Vienna), plate 3.