Can You Bring Boston Ferns Inside During Winter? | Indoor Overwintering Steps

Yes, Boston ferns must be brought indoors before the first frost in most U.S. climates, as they are not frost-tolerant and cannot survive freezing temperatures outdoors.

That lush porch fern heavy enough to be a fire hazard has a short outdoor shelf life if you live anywhere colder than USDA zone 8. The good news is Boston ferns adapt well to indoor life during cold months — they just slow down and ask for different care. The key is timing the move right, setting up the right indoor conditions, and knowing what to stop doing now that summer is over.

When To Bring A Boston Fern Inside

The hard deadline is the first frost of the season — that single dip to 32°F (0°C) turns a healthy fern into a brown, mushy mess overnight. If you live in USDA hardiness zone 8 or below, bring the fern indoors well before that moment arrives.

In warmer zones (9–11), Boston ferns can sometimes stay out all winter, but most gardeners in zone 7 and above still move them inside or provide serious protection when a freeze is forecast. A safe rule: once nighttime temperatures start dipping into the 40s, it is time to act.

If possible, acclimate the fern gradually over a few days instead of yanking it from 80°F porch life into a 68°F living room. Bringing it inside for progressively longer stretches softens the shock.

Prep Work Before Moving

Skip the “bring it in and hope” approach. A little prep prevents the indoor disasters — pests, shedding, and rot — that kill more ferns than the cold itself.

• Inspect every frond for aphids, spider mites, or scale. These love hitching a ride inside and will explode in your warm house.
• Rinse the whole plant with a garden hose to knock off any bugs and loose debris. Some gardeners follow up with a gentle insecticidal soap spray as insurance.
• Cut away all brown, yellow, or dead fronds at the base. Also remove any debris from the crown — dead leaves trapped there invite rot.
• If the fern has grown too big for its pot, transplant it into a slightly larger container with fresh potting mix before moving indoors. Disturbing the roots and the environment at the same time is one shock too many.

Where To Put It Indoors

Boston ferns need three things inside: bright indirect light, stable temperatures, and humidity. A south-facing window is usually ideal — the winter sun is weaker, so direct exposure rarely burns the leaves the way it would in July.

Avoid spots near heating vents, radiators, drafty windows, or exterior doors. Hot dry air from a vent will crisp the fronds within days, and a cold draft from a leaky window stresses the plant just as much.

How To Keep It Alive Through the Cold Months

Winter care is mostly about not doing what worked in summer. The plant is resting, so everything gets scaled back — except humidity.

Light Requirements

Place the fern in bright, indirect light. A sheer curtain over a south-facing window provides ideal filtered brightness. Without enough light, the fern will drop fronds faster than it grows new ones, but direct sun indoors can still scorch it.

Watering Schedule

Keep the soil consistently moist but never soggy. Water when the top inch of soil feels dry to the touch — about once a week for most indoor conditions, but check by feel rather than the calendar. The root ball must not dry out completely, because a dehydrated Boston fern does not bounce back the way a succulent would.

Humidity (The Hardest Part)

Dry indoor air is the biggest threat to an overwintering Boston fern. The fronds will brown at the tips and start dropping if the air is too dry. Solutions that work:

• Humidifier in the same room — the most effective method, especially if you run it nearby.
• Pebble tray filled with water placed under the pot (keep the pot above the water line so the roots are not sitting in it).
• Grouping the fern near other houseplants so they create a shared humid microclimate.
• Bathroom placement if that room has a window — the steam from showers provides consistent moisture.

Occasional misting helps in a pinch but evaporates too quickly to be the primary humidity source.

Fertilizer

Stop feeding the fern once it is indoors for winter. Applying fertilizer during the dormant period pushes weak, pale growth that the plant cannot sustain. Save the liquid fertilizer for early spring when new growth naturally resumes.

Boston Fern Winter Care At A Glance

What To Do If The Fern Looks Rough After Moving Indoors

Some leaf drop and browning after the move is normal — the plant is adjusting to dramatically different light and humidity. But if it goes south fast, here is how to troubleshoot:

• Fronds turning yellow and dropping: likely too little light or too much water. Move it to a brighter spot and let the soil dry back slightly before watering again.
• Brown crispy tips on otherwise green fronds: not enough humidity. Add a pebble tray or move the fern to a more humid room.
• Fronds turning brown from the base up: possible root rot from overwatering. Check for mushy roots — if present, trim the dead roots and repot in fresh soil.
• Pale, leggy growth: too little light. The fern is stretching toward the window. Move it closer.

If the fern drops most of its leaves despite good care, do not give up — cut back the dead fronds heavily and keep the soil barely moist. Many Boston ferns that lose all their leaves indoors still send up new growth in late winter or early spring.

When To Move It Back Outside

Wait until all danger of frost has passed in spring — usually when nighttime temperatures stay above 50°F consistently. Re-acclimate the fern gradually: bring it outside for a few hours of shade each day over a week before leaving it out full time. Resume normal summer watering and restart a monthly dose of balanced liquid fertilizer when new growth is well underway.