How to Transition Plants Indoors for Winter

Summer is ending. The nights are getting cooler. Your outdoor plants that thrived on the patio all season are about to face their first frost.

If you want them to survive winter, it’s time to bring them inside.

But you can’t just carry them in and call it done. Plants need time to adjust. And you definitely don’t want to bring outdoor pests into your home.

Here’s how to transition plants indoors without creating chaos.

When to Bring Plants Inside

Timing matters. Don’t wait until the first frost warning. By then, it’s too late and you’ll be scrambling.

General timeline:

Tropical plants (pothos, philodendrons, ferns): When nighttime temps drop below 50°F
Succulents and cacti: When nighttime temps drop below 40°F
Herbs (basil, cilantro): Before the first frost (basil dies at 32°F)

Check your local frost dates. Most areas have predictable first frost dates (September-October in most of the US). Plan to bring plants in 2-3 weeks before that date.

Why early? It gives plants time to adjust gradually. The temperature difference between outdoor and indoor is less drastic in early fall than late fall.

Step 1: Inspect for Pests

This is non-negotiable. Outdoor plants are magnets for pests. If you bring them inside without checking, you’ll infest your entire indoor collection.

Common outdoor pests:

Aphids (tiny green, black, or white bugs on leaves and stems)
Spider mites (tiny red or brown dots, fine webbing on leaves)
Whiteflies (tiny white flies that scatter when you touch the plant)
Mealybugs (white cottony clusters)
Scale (brown or tan bumps on stems)
Fungus gnats (tiny flies in the soil)
Slugs and snails (check under pots)

How to inspect:

Check the undersides of leaves (most pests hide there)
Look at new growth and along stems
Check the soil surface for gnats
Flip the pot over and check for slugs hiding underneath

What to do if you find pests:

Hose down the plant to knock off aphids, spider mites, and whiteflies
Wipe leaves with insecticidal soap or neem oil
Spray neem oil or insecticidal soap on the entire plant (top and bottom of leaves, stems, soil surface)
Let the plant sit outside for another week, then re-inspect before bringing it in

Pro tip: Even if you don’t see pests, spray plants with neem oil as a preventive measure. Outdoor plants always have something lurking.

Step 2: Clean the Plant and Pot

Outdoor plants collect dirt, dust, spider webs, and random debris. Clean them before bringing them inside.

How to clean:

Hose down the entire plant to remove dust and debris
Wipe large leaves with a damp cloth
Scrub the outside of the pot to remove dirt and algae
Check drainage holes for insects or egg sacs
Remove any dead leaves or spent flowers

Pro tip: This is also a good time to trim back overgrown plants. Outdoor plants often get leggy during summer. Prune them to a manageable size before bringing them in.

Step 3: Quarantine New Arrivals

Even after inspecting and cleaning, some pests are microscopic or hidden. Quarantine outdoor plants away from your indoor collection for 1-2 weeks.

How to quarantine:

Place outdoor plants in a separate room (bathroom, spare bedroom, garage)
Keep them away from your indoor plants
Check them every few days for signs of pests
If you see any pests, treat immediately

Why quarantine? Spider mite eggs can survive on plants for weeks. Aphids can hide in crevices you can’t see. Quarantine gives you a buffer before pests spread.

Step 4: Adjust Light Gradually

Outdoor plants get much more light than indoor plants, even in shade. Moving them from bright outdoor light to dim indoor light is a shock.

Signs of light shock:

Leaves turning yellow and dropping
Wilting even when soil is moist
Stunted growth

How to transition light:

Week 1: Move plants to a shaded outdoor spot (under a tree or covered porch)
Week 2: Move them to a bright indoor spot near a window
Week 3+: Adjust to their final indoor location

Pro tip: If you don’t have time for a gradual transition, place plants in the brightest indoor spot you have (south or east-facing window) and expect some leaf drop. They’ll adjust, but it won’t be pretty.

Step 5: Adjust Watering

Outdoor plants in bright sun and wind dry out fast. Indoor plants in lower light and still air dry out much slower.

If you keep watering at the same frequency, you’ll overwater and cause root rot.

How to adjust watering:

Check the soil before watering (stick your finger 2 inches down)
Water only when the top 2 inches of soil are dry
Expect to water less frequently indoors (maybe half as often)

Pro tip: Indoor air is drier in winter due to heating. You may need to water slightly more often than you expect, but still less than outdoors.

Step 6: Increase Humidity

Most homes have dry indoor air in winter (30-40% humidity). Tropical plants prefer 50-60% humidity.

Signs of low humidity:

Brown, crispy leaf edges
Leaves curling inward
Buds dropping before opening

How to increase humidity:

Use a humidifier near your plants
Group plants together (they create a microclimate)
Place pots on pebble trays filled with water (pot should sit above water, not in it)

What doesn’t work: Misting leaves. It only raises humidity for a few minutes and can cause fungal issues.

Step 7: Reduce Fertilizer

Plants grow slower in winter due to less light. They don’t need as much fertilizer.

Winter fertilizing schedule:

Reduce fertilizer to once every 6-8 weeks, or stop completely
Resume regular fertilizing in spring when growth picks up

Why? Excess fertilizer in winter leads to salt buildup, root burn, and weak, leggy growth.

What to Expect After Transition

Even with perfect care, your plants will go through an adjustment period.

Normal reactions:

A few yellow leaves dropping (the plant is shedding leaves that got too much sun)
Slower growth (less light = less energy)
Slightly droopy appearance for a few days

Not normal:

Massive leaf drop (more than 20% of leaves)
Brown, crispy leaves appearing suddenly
Mushy stems or foul smell (sign of root rot)

If you see abnormal symptoms, check for pests, root rot, and overwatering.

Plants That Shouldn’t Come Inside

Not all outdoor plants are worth saving. Some are annuals that will die anyway. Some are too big or messy for indoor life.

Leave outside:

True annuals (petunias, impatiens, marigolds) - they’ll die no matter what
Plants that are diseased or pest-infested beyond saving
Plants that are too large to fit comfortably indoors

Compost them or let them die naturally. Don’t waste time and space on plants that won’t thrive indoors.

My First Indoor Transition Was a Disaster

The first time I brought outdoor plants inside, I skipped the pest inspection. Within two weeks, I had a spider mite infestation that spread to every plant in my house.

I spent months battling spider mites. Neem oil. Insecticidal soap. Quarantine. It was miserable.

Now I’m paranoid. Every outdoor plant gets hosed down, sprayed with neem oil, and quarantined before it comes anywhere near my indoor collection.

My kids think I’m overreacting. But they didn’t have to wipe down 30 plants every day for three months.

Lesson learned.

The Bottom Line

To transition plants indoors for winter:

Bring them in 2-3 weeks before first frost
Inspect and treat for pests (non-negotiable)
Clean the plant and pot
Quarantine for 1-2 weeks away from indoor plants
Adjust light gradually if possible
Water less frequently than you did outdoors
Increase humidity with a humidifier or pebble trays
Reduce or stop fertilizing until spring

Your outdoor plants can survive winter indoors. But you have to do it right.

Skip the pest check, and you’ll regret it. Trust me.