Bring houseplants inside when nighttime temperatures start dropping consistently into the 50s °F, and before the first frost. Most houseplants are tropical, and extension sources warn that many show damage in the mid-to-low 40s and that nearly all die in a freeze. Do not move them straight from the porch to the living room. Rinse and inspect them outdoors, step the light down over about a week, then keep them apart from your other plants for three to four weeks so any pests that hitchhiked in show themselves.
This guide walks through when to move plants, a simple step-by-step plan, and how to adjust care once they are indoors.
When to Bring Houseplants Inside
There is no single date, because it depends on where you live. Watch nighttime lows rather than the calendar. The extension sources we reviewed use slightly different markers:
- Iowa State University Extension: move plants in when nighttime temperatures dip consistently into the 50s °F. Most houseplants suffer damage in the mid-to-lower 40s °F and die below freezing.
- University of Illinois Extension: bring plants in when the temperature starts getting below 55 °F consistently.
- University of Minnesota Extension: temperatures dipping below 45 to 50 °F can cause damage.
The practical takeaway is to start planning when nights hit the mid-50s, and to bring plants in earlier if a cold night is forecast. If you are unsure, check your local forecast and err on the early side. A plant that spends a few extra days indoors is better off than one that gets chilled.
A Step-by-Step Plan for Moving Plants Indoors
1. Choose their indoor spots first
Decide where each plant will go before you move it. Indoor light is much dimmer than outdoor light, so plan for the brightest spots you have. Our guide to bright indirect light shows how to test a location.
2. Inspect and rinse the plants outdoors
Plants that spend the summer outside can carry pests indoors, where they spread quickly. Extension sources name aphids, whiteflies, mealybugs, scale, and spider mites as the usual suspects. Iowa State recommends rinsing off the foliage thoroughly while the plants are still outside and letting them dry before they come in. Check the undersides of leaves, the stems, and the soil surface.
- Soil dwellers: Illinois Extension suggests flushing pots with water to drive out insects such as ants and earwigs, and repotting if ants are living in the mix.
- Pots: University of Minnesota Extension suggests washing the outside of the pots too.
- Stuck-on pests: Illinois notes that firmly attached insects such as scale can be scraped or wiped off.
3. Prune or repot only if you need to
University of Minnesota Extension notes that some plants may have outgrown their pots over the summer, while others may be too large for the space and need to be pruned, divided, or propagated. If a plant is fine as it is, leave it alone. Moving indoors is change enough.
4. Step the light down gradually
Illinois Extension suggests moving plants to a shadier spot outdoors for about a week, then bringing them in. Once indoors, give them bright, indirect light. Iowa State notes that some plants will drop leaves in response to the lower light, and that new growth replaces them. That leaf drop is common and is not a sign you did something wrong.
5. Keep them apart for three to four weeks
Both Iowa State and Illinois Extension recommend isolating plants that have been outdoors for three to four weeks before they sit next to your other houseplants. If scale, mealybugs, aphids, or whiteflies are going to appear, they usually show up within that time. A yellow sticky card nearby helps you spot flying pests early. If you see small flies near the soil, our guide to fungus gnats in houseplants explains what to do.
6. Adjust your care for winter
- Water less. Illinois Extension suggests letting the soil dry slightly between waterings, since plants use less water in lower light. Check the soil rather than following a schedule. Our guide to how often to water houseplants explains how.
- Stop fertilizing. Iowa State and Illinois both advise stopping fertilizer in fall and winter, since plants are not actively growing.
- Use your brightest window. Illinois suggests south- or west-facing windows for winter.
- Watch the air. Heating can dry the air. Illinois suggests grouping plants, using a humidifier, or using a pebble tray, and our guide to increasing humidity for tropical houseplants compares the options. Keep plants away from heating vents and cold drafts.
- Add light if needed. Iowa State notes that supplemental lighting can help when indoor light is too low. See our guide to grow lights for houseplants.
Pests to Check For, and a Safe First Response
Start with the gentlest methods. University of Minnesota Extension and Clemson Extension both recommend washing the plant first, then removing what remains by hand.
- Spider mites: tiny, about 1/50 inch, and often visible first as a stippled look on the leaves. Spray sturdy plants forcefully with water, including the undersides.
- Mealybugs: soft-bodied insects with white, waxy coverings. Wipe them off with a cotton swab dipped in rubbing alcohol.
- Scale: small oval or round bumps on stems and leaves. Scrape or wipe them off.
- Aphids and whiteflies: small sap-feeding insects, often on new growth. Rinse them off with water.
If washing and wiping are not enough, Clemson notes that insecticidal soap can often eliminate an infestation in its early stages. It also warns that some houseplants are sensitive to soap, including ivy, maidenhair fern, dieffenbachia, schefflera, jade plant, and begonia. Follow the product label, check that it allows indoor use, and where possible treat plants outdoors and let them dry before bringing them in.
Common Mistakes
- Waiting for the first frost. Plants can be damaged well above freezing.
- Going from full sun to a dim room in one day. The sudden change is a common cause of leaf drop.
- Skipping the pest check. A few hitchhikers outdoors can become an infestation indoors.
- Putting returning plants next to the rest of your collection. Quarantine first.
- Keeping the summer watering and fertilizing routine. Lower light means the plant uses less of both.
From the Greenhouse Bench
The same logic applies to a plant that comes to you in a box. Our Help page tells you to put a new arrival somewhere with good indirect light, to check whether the soil is dry before watering, and to skip repotting and fertilizing for a couple of weeks while the plant settles. Plants coming in from a summer outside need the same kind of patience. Give them steady light, check the soil before you water, and let them adjust before you make any bigger changes.
Frequently Asked Questions
What temperature is too cold for houseplants?
Iowa State Extension notes that many houseplants are damaged in the mid-to-lower 40s °F and that nearly all die below freezing. University of Minnesota Extension gives 45 to 50 °F as the point where damage can start.
Should I repot before bringing plants inside?
Only if a plant has clearly outgrown its pot or has pests in the soil. If it is doing fine, leave it as is and let it adjust to being indoors first.
Why is my plant dropping leaves after I brought it inside?
Often it is the change in light. Iowa State notes that some plants drop leaves in response to lower indoor light, and that new growth replaces them. Keep the plant in the brightest suitable spot and avoid moving it again.
Do I need to spray my plants for bugs before bringing them in?
Not necessarily. Start by inspecting and rinsing the plants with water. Use insecticidal soap or another product only if you find pests and the label allows it for the plant and for indoor use.
How long should I keep plants separate from my others?
Iowa State and Illinois Extension both suggest three to four weeks for plants that have been outdoors.
The Short Version
Watch the nighttime lows, rinse and inspect outdoors, step the light down, quarantine for three to four weeks, and water and feed less. If you are bringing in plants that will sit in a dim spot, read our guide to signs a houseplant needs to be relocated to know what to watch for.
Sources: Iowa State University Extension: bringing houseplants back indoors, University of Illinois Extension: moving houseplants indoors, University of Minnesota Extension, and Clemson Cooperative Extension. Always follow the label on any pesticide product.