Every October it happens the same way. We go to bed in the 90s, a norther blows through around midnight, and by breakfast my phone is full of texts that all ask the same thing: “Do I need to bring my plants in?”
This year it came through on a Thursday night in the middle of October. One last 93-degree afternoon, a wall of north wind, and by the weekend we were looking at mornings in the 40s. After the summer we just had, it feels like winter showed up overnight.
It didn’t. For most of you the answer is no. Leave them out. Here’s how I actually make that call with my own plants and my clients’, and the handful of things a first cold front genuinely does call for.
#1 — The Number on the News Isn’t the Number on Your Porch
Austin’s official temperature comes from Camp Mabry, which sits in the middle of town and stays warmer than most of the metro on a cold night. Your plant doesn’t live at Camp Mabry. It lives on your porch, and where exactly on your porch matters more than people think.
A pot sitting out on open ground on a clear, calm night can run several degrees colder than the forecast, because it’s losing heat straight up to the sky. The same pot tucked under a porch roof and pushed against a brick or limestone wall can run several degrees warmer. The overhang stops that heat loss, and the wall gives back the warmth it soaked up all afternoon. That gap is often the whole difference between a plant that shrugs off a cold morning and one that sulks for a week.
And if you live out past the Y, in Dripping Springs, Wimberley, or anywhere in a Hill Country valley, knock a few more degrees off whatever the Austin forecast says. The Hill Country typically sees its first freeze around mid-November. Central Austin usually doesn’t get one until around the first of December. Same forecast on the TV, very different night in your yard.
So the first thing I do after a front like this isn’t bring anything inside. It’s push the pots together under the overhang, against a south or east wall, off the open patio. That one move buys more protection than most October mornings will take away.
#2 — Know Which Plants Actually Mind the 40s
Most of the tropicals people keep on Austin porches handle a night or two in the upper 40s just fine. Monsteras, pothos, most philodendrons, birds of paradise, rubber trees: a 47-degree morning on its way to a sunny 70-degree afternoon doesn’t bother them. They’ll slow down a little and that’s it.
The fussy ones are a different story. Calatheas, aglaonemas, crotons, alocasias and dieffenbachias start to complain in the upper 40s. You’ll see dull or curling leaves, maybe some dark spotting a few days later. Those are the ones I’d give the most sheltered spot you’ve got, and if you’re out in the Hill Country with a forecast low in the mid-40s, bringing just those few in for a night or two is reasonable. Not the whole porch. Just the divas.
The line that matters for everything is 40 degrees. Down in the low 40s and below, cold damage stops being cosmetic and turns into black, mushy stems you can’t undo. My rule, which I go into more in my guide to keeping tropicals outdoors in Austin: if the forecast shows the low 40s anywhere in the next 48 hours, plants come in the night before. Not the morning of.
How long the cold lasts matters too. An hour at 47 right before sunrise is nothing like a night that sits in the low 40s for ten hours. Most early fall fronts here give you the first kind.
#3 — This Week’s Real Problem Is the Wind and the Dry Air
Here’s what the first front actually brings that people don’t think about. It isn’t just cooler air. It’s a hard north wind, often gusting 30 or 40 miles an hour, and humidity that drops from summer’s swamp straight down into the 20s. After four months of sticky Gulf air, that’s the shock your plants are feeling right now. Not the temperature.
Big soft leaves take it worst. Birds of paradise, bananas and elephant ears will shred in a day of that wind. Tall plants in lightweight plastic nursery pots tip over, and I’ve seen more broken monstera stems from a porch tumble in October than from anything the cold did. Move the tall ones out of the wind, set them against something solid, or lay them on their side for a windy afternoon if that’s the only option.
Then check the soil. Nobody thinks about watering when it’s sweater weather, but a cool, sunny, windy day with 20-percent humidity pulls water out of a pot faster than you’d expect. Stick a finger in. If it’s dry a couple of inches down, water in the morning so the pot drains and warms up through the day. What you don’t want is to water in the evening right before a cold morning. Cold, soggy roots are how a harmless 45-degree night turns into rot.
#4 — Bring Them In Now and You’ll Want Them Back Out by Midweek
These first fronts don’t stick. That’s Austin in October. We drop into the 40s for a couple of mornings and then we’re right back in the 80s by the middle of the next week. The calendar says fall. The weather says maybe.
Haul everything inside now and here’s what happens. Your plants go from a breezy porch into a house where the AC kicks right back on the moment it warms up again. That sudden drop in light and humidity is what makes porch plants drop leaves the first week back indoors. Worse, any spider mites that were hitching a ride, held in check outside by humidity and the bugs that eat them, now have dry air and no predators. Two mites become two thousand in about ten days. I’ve written about what that looks like in my post on Austin houseplant pests.
Then the next warm spell comes and you carry them all back out, and you do it again with the next front. Every one of those moves is a shock. I’d rather move a plant once, at the right time.
There’s also something you give up by bringing them in early. October and the first half of November are some of the best growing weeks of the whole year here. Mild days, cool nights, decent light, no more scorching afternoons. A plant on the porch right now is in better conditions than it saw all summer. Let it have them.
#5 — Use This Weekend to Get Ready for the Real Move
So when do they actually come in? For most of Austin, that’s sometime in November, whenever the 48-hour forecast first shows the low 40s. Central Austin’s average first freeze is around December 1, the airport side of town runs a few days earlier, and the Hill Country gets there around mid-November. The earliest freeze ever recorded in Austin was October 26, 1924, so it’s not impossible this month, which is exactly why you watch the forecast instead of the calendar.
But a cool, dry, sunny weekend is the best weather you’ll get all year for the prep work, so this is when I’d start. Go plant by plant and look at the tops and undersides of the leaves in good light. Hose each one down hard, undersides included. Treat with insecticidal soap. Flush the soil and let it drain. If anything had a pest problem this summer, deal with it now, outside, where an overspray doesn’t matter.
Then walk your house and decide where each plant is going to live. Light changes fast this time of year. A spot that was bright in July can be dim by Thanksgiving because the sun is lower and coming in at a different angle. I explain exactly why in my post on what Austin’s winter light does to houseplants. Pick spots near the south and west windows, away from heating vents, and clear the floor space now.
Do all that this weekend and the actual move, whenever it comes, is a twenty-minute job instead of a panicked night with a flashlight and a forecast alert.
And If Your Plants Live Inside All Year
Good news: enjoy the break. Your AC is finally cycling less, which means the air in your house is less brutal than it’s been since May. If you’ve got the windows open to enjoy it, just keep plants out of the direct path of that dry north wind, and start easing off the watering as the days get shorter. Nothing else to do yet.
The time to think about cold for indoor plants is the first real freeze, when the air right against the window glass can sit twenty degrees colder than the rest of the room. That’s covered in my Austin freeze prep guide, and it’s worth a read before Thanksgiving.
Want a Hand With It?
If you’ve got a porch full of big tropicals and the thought of inspecting, treating and hauling every one of them inside sounds like a lost weekend, that’s something I do for clients through Keep Austin Watered. I do the pest treatment outside, move everything in, and find each plant a spot that’ll actually hold up through an Austin winter, away from the vents and in the light it needs. Text me a photo of your porch and I’ll tell you honestly whether you need me or just a free Saturday.
Book a free consult with Will or text (512) 829-1467.
Further reading
Tropical Houseplants Outdoors in Austin — the rules for porches, acclimating, and the 40-degree line.
Austin Freeze Prep — for when a real freeze is on the way.
Common Houseplant Pests in Austin — what to check for before anything comes back inside.
Austin Winter Houseplant Care — why your plants look worse in January, and how to get ahead of it.
Austin Summer Plants — what this summer’s heat and AC did to the plants you’re looking at now.