Boston Fern / Sword Fern

Nephrolepis exaltata

description

Boston Fern is a classic arching fern with dense feathery fronds.

benefits

Low—light tolerant
Pet-friendly, non-toxic to animals
Suitable for containers

How to care for Boston Fern

sunlight

Boston Ferns grow beneath tree canopies, where light is bright but softened by leaves. Place yours in bright, filtered light to keep its fronds dense and fresh.

Medium indirect light

Tolerated, especially near an east or north window. Growth may slow and fronds may become thinner in dim rooms.

Bright indirect light

Ideal near an east-facing window or a few feet back from a brighter window. Keep it out of hot direct sun, which can scorch and fade the fronds.

If the fronds look pale or crispy, move the fern farther from the glass. If growth is sparse, bring it closer to filtered light.

watering

Keep the potting mix evenly moist, never bone dry or waterlogged. Boston ferns shed fronds quickly when their roots dry out.

Spring - summer

Water thoroughly about every 3-5 days in bright, warm conditions. Check every few days and water when the top 1 cm of mix feels just dry, while the root ball beneath still feels lightly moist. Let excess drain away.

Autumn - winter

Growth slows in lower light, so watering is often needed roughly every 7-10 days. Use the same surface check rather than a fixed calendar, especially in a cool room.

Lift the pot after watering and again before the next drink. A noticeably lighter pot is a useful sign that the fern is ready.

Sun, heat, dry air, small pots, terracotta, and a fast-draining mix make the plant dry sooner. Larger pots, low light, cool temperatures, and slower root growth extend the interval.

Do not leave the pot standing in water. Constantly saturated mix can rot the fine roots.

humidity

Preferred humidity

50-70%

Boston ferns come from humid tropical and subtropical habitats, so they stay fullest in consistently moist air. Average homes are usually fine at 40-50%, but dry heated or air-conditioned air can quickly brown the fronds.

Lowest comfortable level

About 40%

Below this, watch for crisp brown tips, dry leaflet edges, and increased frond drop. Do not compensate for dry air by keeping the pot soggy.

Group it with other plants or use a humidifier nearby for the most reliable boost.

Keep it away from radiators, heating vents, and strong air conditioning.
A pebble tray adds only a small boost, but can help in a sheltered spot.
Misting is temporary, so use it for appearance rather than as the main solution.

temperature

Preferred temperature

18-24°C (65-75°F)

Winter minimum

13°C (55°F)

Boston Fern comes from warm, humid tropical and subtropical habitats, so it is happiest in steady indoor warmth. Keep it away from chilly windows in winter and from hot, dry air from radiators or vents.

If the room feels cool at night, move the fern a little farther from the glass and check that it stays above 13°C (55°F).

Cold drafts and sudden temperature swings can cause fronds to yellow or brown.

nutrition

April - September

Feed about once a month while new fronds are growing, using a balanced liquid houseplant fertilizer at half strength. Apply it to already moist soil. Stop feeding in autumn and winter unless the fern is clearly making steady new growth.

Nitrogen

Nitrogen supports the fern's lush green fronds. A diluted balanced fertilizer supplies enough without pushing soft, weak growth.

Use a weak feed rather than a strong one: brown frond tips or a white crust on the soil can mean fertilizer salts are building up. Flush the pot with water occasionally.

soil

Rich, airy soil that stays lightly moist

Boston fern prefers humus-rich potting mix that holds some moisture without becoming dense or soggy. Use a quality indoor potting mix with compost or coco coir, plus perlite or fine bark to keep air around the roots.

pH 5,5 - 6,5

This is slightly acidic soil, which suits fern roots and nutrient uptake. Most peat- or coco-based houseplant mixes fall close to this range, so there is usually no need to adjust pH at home.

Use a pot with drainage holes, and refresh compacted soil when repotting every year or two.