Bringing houseplants inside for winter — a guide

Every plant that summered outdoors has to make the return trip, and autumn is where a good year outside can quietly go wrong. The plants that fattened up in real daylight now have to squeeze back through the door — and they bring the season's pests, sunburn-toughened leaves, and a set of expectations the living room can't meet. Get the move right and they slide into winter without missing a beat. Rush it, skip the pest check, or leave it too late, and you're nursing a leggy, bug-ridden plant through the darkest months. This is the hub for the whole autumn move indoors: when to bring plants in, and the three-step sequence that gets them there cleanly. Each step is summarised here and linked out to a dedicated deep-dive.

Let Growli time the move: Add your plants to Growli and it tracks the forecast and each plant's tolerance, then recalculates watering reminders for the darker indoor months — so you're prompted less often and tuned to the plant, not a fixed schedule.

This guide closes our seasonal loop. It's the reverse of how to move houseplants outside for summer, and it hands off to houseplant winter care — the complete guide once your plants are settled inside.

When to bring houseplants indoors: the night-temperature rule

The number that decides the timing is the overnight low, not the daytime high. A mild, sunny 70°F afternoon means nothing to a tropical plant if the temperature slides to 45°F after dark. Most of our houseplants come from warm climates, and cold nights stress them long before any frost appears — so the mistake to avoid is waiting for that first frost warning. By then the damage is often already done.

The established guidance from US Extension services is to move houseplants back indoors when nighttime temperatures start to dip consistently into the 50s°F (roughly 10–12°C). Iowa State University Extension advises bringing plants in well before nights get too cold, noting that damage sets in around the mid-to-lower 40s°F and freezing temperatures are fatal to tropicals. Michigan State University Extension puts a working date on it for a cold northern climate — aim to have plants inspected and moved back indoors by around mid-September — precisely so they never meet a light frost.

In much of the northern US that threshold arrives in September; further south, later. In the UK, the equivalent is to bring plants in past your first autumn frost risk and once nights settle into single-digit Celsius — typically September into October depending on how far north you are. A popular rule of thumb worth knowing is the "50-50": get tender plants inside roughly 50 days before your average first frost, or once nights are reaching the mid-50s°F. A few practical timing notes:

• Watch the ten-day forecast, not the calendar. One cold snap in early September can arrive before the "average" first frost. Move plants in ahead of a forecast dip, not after it.
• Bring your most tender tropicals in first. Anything that sulks below 50°F — begonias, tropical hibiscus, crotons, many aroids — leads the queue. Sturdier plants can trail a week or two behind if nights stay mild.
• When in doubt, go early. There's no prize for the last plant on the patio, and a single chilly night can undo a whole summer of growth.

Why it's a sequence, not a single lift

It's tempting to grab everything on the first cold evening and haul it straight to the windowsill. Don't. A plant carried directly from patio to living room walks three problems through your front door at once: pests it picked up outdoors, leaves built for bright outdoor sun that now face a dim room, and a watering rhythm tuned to sun and wind that will drown it indoors. Handle them in order and the move is easy. The rest of this guide is that order — three steps, each with a dedicated guide for the detail.

Step 1: Inspect and de-bug before they cross the threshold

This is the step people skip and regret all winter. Outdoors, your plants rejoined the food chain, and aphids, spider mites, scale, mealybugs and whitefly can all be riding along — plus soil dwellers like fungus gnats, ants and sowbugs hiding in the pot. Bring one infested plant inside and, without the predators and weather that kept pests in check outdoors, an infestation can explode across your indoor collection over winter.

Do the inspection outside, well away from your indoor plants — a garage bench, a shaded patio corner — so nothing jumps ship while you work. The MSU Extension routine is thorough: water the plant, slide it out of its pot to check the soil (especially the bottom) for ants, sowbugs and pillbugs, then examine stems and both sides of every leaf for insects and eggs. A magnifier helps for the tiny ones. Then clean before you carry anything in:

• Rinse the foliage thoroughly with a hose while the plant is still outside, and let it dry completely before it comes in — the Iowa State Extension step that catches a lot of hitchhikers.
• Treat what you find. MSU notes that a commercially prepared insecticidal soap is a good choice for spider mites or aphids; cover every surface, leaf tops and undersides included. Repeat treatments are usually needed to break the pest's life cycle.
• Quarantine returning plants away from your indoor collection for three to four weeks, checking regularly, so any survivors reveal themselves before they can spread.

It is far easier to deal with a pest on the patio than loose in the house. For the full method — the pest-by-pest identification, treatment options and how long to isolate — see the dedicated guide to checking houseplants for pests before bringing them in. (If any treatment choice depends on pets or children in the home, check product guidance and our pet-safe notes before you spray.)

Step 2: Acclimate to lower indoor light

Here's the shock most owners underestimate: even a bright windowsill is dim compared with the outdoors. Real daylight is many times more intense than the light near a window, so a plant moved straight from the patio to a living room can suddenly find itself in what amounts to deep shade. The usual response is a wave of leaf drop as the plant sheds foliage it can no longer power — Iowa State singles out tropical hibiscus as a classic example, and it happens to figs, crotons and others too. It looks alarming but it's an adjustment, not a death sentence: new, shade-adapted leaves grow in over the following weeks.

You can soften the blow by reversing the summer hardening-off. Rather than one abrupt switch, ease the plant down through gradually shadier outdoor spots for its final days out, then give it your brightest available window indoors — south- or west-facing is best for the low autumn sun. A few working notes:

• Expect some leaf drop and don't overreact. Resist the urge to "fix" a shedding plant by watering more or feeding — that makes things worse. It's re-tooling its leaves for the light it now has.
• Clean the glass and the leaves. Every bit of light counts in autumn; wipe dust off foliage and give windows a clean so the plant works at full capacity.
• Consider a grow light for genuinely dark rooms or light-hungry plants, easing them onto it rather than blasting them from day one.

For the step-by-step on reversing the hardening-off, reading indoor light levels and getting plants through the drop with the fewest leaves lost, see acclimating houseplants back indoors in autumn.

Step 3: Settle into autumn and winter care

Once a plant is inside, clean and adjusting to the light, its whole care routine has to change with the season — and the number-one adjustment is water. The sun-and-wind conditions that dried a pot in a day outdoors are gone; indoors, in cooler and darker autumn rooms, that same pot stays wet for far longer. Keep watering on the summer schedule and you'll rot the roots. Switch to watering by the soil, not the calendar: feel the top inch, and only water when it's dry. Ease off feeding too, since shortening days slow growth to a point where plants can't use much fertiliser.

Autumn is the true transition month — plants are downshifting, not yet fully resting — so it gets its own playbook. For that whole set of adjustments (the watering reset, when to make your last feed, managing dry heated air as you switch the heating on, and what to expect from slowing growth), read fall houseplant care — the autumn transition. When the days shorten fully and growth stops, the deeper cold-weather routine takes over in houseplant winter care — the complete guide — water, feeding, light, humidity and keeping plants off cold glass, all in one place.

A sensible order for a crowded patio

If you've got more plants than hands, don't do it in one weekend. Stage the move over a couple of weeks, tender-first:

1. Most cold-sensitive first — tropical hibiscus, begonias, crotons, aroids and anything that flags below 50°F. These come in as soon as nights start reaching the mid-50s°F.
2. Big tropical foliage next — monstera, philodendron, rubber plants, dracaenas, palms — as nights settle into the low 50s.
3. The toughest last — sturdier, cooler-tolerant plants can wait for the final mild nights, but still get them in before any frost.

Inspect and de-bug each batch as it comes in, and quarantine the lot together, away from plants that never went outside.

Your bring-them-in checklist

1. Watch the overnight lows. Plan to move tropicals in before nights dip consistently into the 50s°F (10–12°C), and always ahead of the first frost.
2. Inspect outside. Slide plants from their pots, check soil, stems and leaf undersides for pests.
3. Clean and treat. Rinse the foliage, treat any pests with insecticidal soap, and let plants dry before they come in.
4. Quarantine for 3–4 weeks away from your indoor collection.
5. Give them your brightest window and expect some leaf drop as they adjust to lower light.
6. Reset the care routine — water by the soil, stop feeding, and follow the autumn-into-winter guides.

Fine-tuning the move for a particular plant? Browse our plant-care guides by species for the ones that flag first in the cold and the tough customers that can wait.

Related articles

• Check houseplants for pests before bringing them in — the full inspection, treatment and quarantine routine
• Acclimating houseplants back indoors in autumn — reversing the hardening-off and limiting leaf drop
• Fall houseplant care — the autumn transition — resetting water, feeding, light and humidity for autumn
• How to move houseplants outside for summer — the reverse journey, in spring
• Houseplant winter care — the complete guide — where the autumn move hands off
• Plant-care guides by species — which plants flag first in the cold

Reviewed and updated by the Growli editorial team. For questions about anything here, open Growli and ask — or email hello@getgrowli.app.