PlantWhy

Overwintering outdoor potted plants: what to bring in and how

Many balcony and patio plants are tender perennials: one frost ends them, yet they can live for years if you give them a winter shelter. Some come indoors as living plants, others are dug up and stored dormant. This guide covers which is which, when to move them, and how to keep them going until spring.

Overwintering outdoor potted plants: what to bring in and how
Photo: Andrew massyn, CC BY-SA 3.0 · Wikimedia Commons
Move in
Before the first frost; nights near 45–50 °F
Indoor spot
Cool and bright
Watering
Much less than in summer
Back outside
After the last frost, hardened off gradually

Which plants come in, and how?

Hardy shrubs in large pots can often stay outside with some protection. Frost-tender plants need one of two routes:

Overwinter as living plants

  • Geranium (pelargonium)
  • Rosemary (in cold regions)
  • Bay laurel
  • Lemon, mandarin and other citrus
  • Hibiscus

Store dormant, out of soil

  • Dahlia tubers
  • Gladiolus corms
  • Canna rhizomes
  • Tuberous begonia tubers
Rosemary is not reliably winter-hardy in cold regions; a pot makes moving it easy.
Rosemary is not reliably winter-hardy in cold regions; a pot makes moving it easy. Photo: Margalob, CC BY-SA 4.0 · Wikimedia Commons

When to bring them in

Act before the first frost, not after it. Depending on the species, nights below about 45–50 °F can already harm tender plants, and some sources suggest moving them once temperatures fall below 55 °F.

  • Check the forecast weekly from early autumn.
  • Ease the change: over about a week, shift pots into shadier spots so they adjust to lower indoor light.
  • Citrus and hibiscus are the most cold-sensitive; move them first.

⚠️ A single night of frost can kill geraniums and blacken citrus leaves. If frost is forecast tonight, bring pots in now and do the pest check in a sheltered spot.

Check for pests before they come in

  1. Look under every leaf and along stems for aphids, whiteflies, spider mites and scale.
  2. Rinse the foliage with a strong spray of water, or wash it in a bucket of mild soapy water that also reaches the soil.
  3. Check the drainage hole and soil surface for slugs, ants and earwigs; soaking the pot briefly drives many of them out.
  4. Remove dead leaves, faded flowers and fallen debris from the pot.
  5. Keep the newcomers apart from your houseplants for the first weeks (estimated: 2–3 weeks).
  6. Inside, inspect at every watering; throw out a heavily infested plant rather than risk the rest.

A cool, bright room

Most of these plants rest in winter. The best place is bright but cool: an unheated sunroom, a stairwell window, a cool spare room or a frost-free glazed balcony.

  • Citrus and bay: as much light as possible and a cool room, roughly 50–59 °F (estimated). Keep them away from radiators.
  • Rosemary: a sunny window in a cool or even cold room.
  • Geranium: a bright window; daytime 65–70 °F with slightly cooler nights suits them.
Citrus in pots wants the brightest spot you have in winter.
Citrus in pots wants the brightest spot you have in winter. Photo: Elena Chochkova, CC BY-SA 4.0 · Wikimedia Commons

Water sparingly

Cool plants in low light use little water. Overwatering is the main winter killer.

  • Water only when the top of the mix is dry; push a finger in to check.
  • Empty saucers about 30 minutes after watering.
  • Rosemary should stay on the dry side; wet roots rot.
  • Dry indoor air browns rosemary and citrus leaf tips; a tray of pebbles and water under the pot helps.
  • Don't feed resting plants in winter.
Bay laurel: a cool, bright room and occasional watering get it through winter.
Bay laurel: a cool, bright room and occasional watering get it through winter. Photo: Forest and Kim Starr, CC BY 3.0 US · Wikimedia Commons

Digging and storing tubers and corms

Dahlias: after the first killing frost blackens the foliage, cut stems to 2–4 in. Leave the clumps in the soil (or pot) for another 6–7 days, then dig carefully, starting several inches from the stem. Shake off soil and let them dry for about 24 hours.

Gladiolus: dig in early autumn, cut the leaves 1–2 in above the corm and dry the corms for 2–3 weeks in a warm, airy place.

Storage: pack in peat moss, vermiculite, sand or wood shavings in a box. Keep dahlias at 40–50 °F and gladiolus at 35–45 °F, dry and frost-free. Check them a few times over winter and discard any soft or rotting pieces.

Dahlias bloom again next summer if their tubers are stored dry and cool.
Dahlias bloom again next summer if their tubers are stored dry and cool. Photo: Dominicus Johannes Bergsma, CC BY-SA 4.0 · Wikimedia Commons

Geraniums: three options

Geraniums are the easiest to keep:

  • Whole pot: bring the plant in before frost and grow it in a sunny window. In March, cut it back by one-half to two-thirds; new shoots follow within days.
  • Cuttings: take 4 in tip cuttings from healthy plants and root them; they take less space.
  • Dormant: in a cool, dark place the plant can rest almost dry; this is the less reliable route (estimated).

Moving plants back out in spring

Wait until the last frost has passed and nights stay mild, about 50 °F or warmer (estimated). Then harden plants off:

  • Start with a few hours in shade, out of the wind.
  • Over 1–2 weeks (estimated), increase the time outside and the amount of sun.
  • Bring them in again if a late frost is forecast.
  • Pot up stored dahlia tubers indoors a few weeks earlier for earlier flowers (estimated: 4–6 weeks).

Common problems and fixes

Leaves dropping soon after moving inA normal response to less light. Give the brightest spot and avoid overwatering; new leaves usually follow.
Sticky leaves, small insectsAphids, whiteflies or scale. Rinse the plant and inspect more often; isolate it from other plants.
Fine webbing, speckled leavesSpider mites thrive in warm, dry air. Rinse leaves, move the plant somewhere cooler and raise humidity.
Stored tubers shrivelled or mouldyShrivelled: too dry, add slightly damp packing. Mouldy: too damp, remove affected pieces and air the rest.

Frequently asked questions

Can I just leave a potted rosemary or bay outside?

In mild-winter areas, often yes, sheltered against a wall and with the pot raised off cold ground. Where frosts are hard, roots in a pot freeze much more easily than in the ground, so bring them in.

Why is my citrus dropping leaves indoors?

Usually low light, sudden temperature change or warm, dry air. Choose the brightest, coolest spot and water only when the top of the mix is dry.

Do I have to dig dahlias every year?

Where the ground freezes, yes. In very mild areas they can stay in the ground under a thick mulch, but rot is a risk in wet soil.

Can I store tubers in the fridge?

Not recommended: it is often too damp and holds fruit that releases ethylene. A cool, dry, frost-free garage, cellar or cupboard is better.

Plants that need a winter shelter

GeraniumRosemaryBay laurelLemon TreeMandarinDahliaTropical Hibiscus

Sources

Last updated: November 10, 2026