Moving Houseplants Outside for Summer

When to move out (and the two-number answer)

Iowa State's threshold: nights consistently and reliably above 50 degrees Fahrenheit, which lands mid-to-late May in Iowa; houseplants suffer damage below 45 and die at freezing. Maryland's threshold is more conservative: after night temperatures remain above 60, usually mid-May to early June there. Neither number is wrong; they reflect different risk tolerances and plant mixes, so use 50 as the earliest defensible date and 60 as the safe-for-everything date, adjusted to your own region's forecast rather than the calendar.

Any cold snap below your threshold means carrying pots back in for the night, which is a good argument for starting with the plants you can lift.

Acclimating out: shade first, sun slowly

Indoor light, even in a bright window, is far weaker than outdoor sun, and leaves grown indoors have no defense against the jump. Iowa State says to place plants in a full-shade or part-shade spot first and expand their light exposure over 10 to 14 days; Maryland recommends acclimating in outdoor shade and introducing sun-lovers to brighter spots over two weeks.

Symptoms of rushing it are bleached, scorched, or dropped leaves. Iowa State also flags weeping fig and tropical hibiscus as prone to dropping leaves after any move, with new foliage following within weeks, so don't read normal move-shock as sunburn.

Outdoor plants drink and eat more: Maryland says to water and fertilize more often than indoors because photosynthesis and growth speed up, and Iowa State advises checking the soil frequently and watering thoroughly when it is dry to the touch. Wind and warmth can dry small pots daily.

Coming back in: the pest gate

Move plants back as nights begin dropping toward the same thresholds (Maryland: below 60, usually mid-September; Iowa State: consistently around 50, mid-to-late September there). Reverse-acclimate light-wise if a plant has been in strong sun, and expect some adjustment leaf-drop indoors.

The bigger risk is what rides in on the pots. Iowa State's protocol: thoroughly rinse all the foliage, inspect closely for scale, mealybugs, and whiteflies (check pot rims, drainage holes, and the soil surface too), and isolate returning plants from your other houseplants for 3 to 4 weeks while you watch for outbreaks. Maryland adds that infested plants should be treated with a labeled insecticidal soap or horticultural oil before they come inside.

For identification and follow-up control, see how-to-control-scale-insects, mealybugs-houseplants-and-garden, and spider-mites-in-the-garden.

Sources

Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.

• Iowa State University Extension Yard and Garden — Moving Indoor Plants Outside for the Summer — Move out when nights are consistently and reliably above 50 F (mid-late May in Iowa); damage below 45 F, death at freezing; nearly all houseplants are tropical understory plants — start in full/part shade and increase light over 10-14 days; weeping fig and tropical hibiscus prone to leaf drop after moves; water thoroughly when soil is dry to the touch; return indoors when nights dip consistently to ~50 F; rinse all foliage, inspect for scale/mealybug/whiteflies, and isolate returning plants 3-4 weeks
• University of Maryland Extension — Moving Indoor Plants Outside — Move plants outside only after night temperatures remain above 60 F (usually mid-May/early June); acclimate in outdoor shade and introduce sun-loving plants to sunnier spots over two weeks; water and fertilize more often outdoors due to increased photosynthesis and growth; bring back in as nights drop below 60 F (usually mid-September); check thoroughly for insects and treat infested plants with labeled insecticidal soap or horticultural oil before bringing in

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