The Heater Ran All Night. All Thirty Geraniums Were Mush By Morning.
Five reasons gardeners are carrying the house heater back inside this winter, and plugging in one that reads the temperature beside their pots and holds it until morning.
You Did Everything Right. The Heater Was Still On When You Found It.
You heard the forecast and did the responsible thing. Carried the spare heater out from the den, set it at the end of the bench, ran the cord, turned it up, and went to bed thinking all thirty pots were covered.
Then the morning. Every one of them collapsed at once. Stems gone dark and soft, mush right at the soil line, leaves hanging like wet paper. And the heater, still sitting right there, still plugged in.
Those were the same cuttings you've rooted every fall for fifteen years. Some started as slips from your mother's window boxes. You didn't forget them. You protected them, and they froze anyway. But that didn't happen because you did something wrong. It happened because that heater was built for a completely different job.
A House Heater Is Built to Warm People. Your Geraniums Aren't People.
A living-room heater assumes someone is sitting near it. It's built for an insulated room with walls that hold heat, not a glass box that dumps it the second the sun goes down.
Look at the dial: MIN to MAX. No number on it. So there's no way to tell it "keep the bench above 45." And if it has a sensor at all, it's reading the air right at the heater, the warmest spot in the greenhouse, while the pots at the far end, by the glass, sit several degrees colder. Thirty pots means thirty different spots, and the coldest one decides how many you lose.
Plenty of house heaters also carry auto-off timers built for bedrooms. Great when you're asleep in the next room. Not great when the coldest hour of the night comes after the timer has already clicked off.
| What the geraniums need | House heater | FrostGuard |
|---|---|---|
| A temperature it never drops below | MIN–MAX dial, no number | Set 40–108°F on a digital display |
| A reading where the plant is | At the heater, if anywhere | Probe in the soil beside the roots |
| Heat at 5am, the coldest hour | Only if you got up to check | Fires on its own, every time |
Set It Once. You'll Never Have to Check the Greenhouse Again.
FrostGuard ships with a digital thermostat and a temperature probe on a cable. Push the probe into the pot at the cold end of the bench, the one right by the glass. Set 45. Geraniums turn to mush below freezing, and 45 keeps every pot well clear of it. That's the whole setup. Here's the night now:
| Time | Greenhouse | You |
|---|---|---|
| 9 pm | Probe reads 50. Heater waiting. | On the couch. |
| 2 am | Drops below 45. Heater fires. | Asleep. |
| 2:20 am | Back to 45. Shuts off. | Asleep. |
| 5 am | Coldest hour. Fires again, as often as it takes. | Asleep. |
| 7 am | Sun's up. Heater rests. | Coffee by the geraniums. |
No more flashlight walks. No more guessing. The display shows the live reading at the roots and lights up whenever it's calling for heat, so one glance from the door tells you everything.
Comfortable, Not Cooked. And No Open Flame Next to the Bench.
Blasting a heater on MAX all night isn't protection either. It cooks the pots nearest to it, so they go leggy and soft, while the far end of the bench still freezes. FrostGuard holds a floor: it only adds heat until the probe reads your number, then stops. Warm enough for every pot on the bench, without turning the whole greenhouse into a sauna.
And the thing every greenhouse owner thinks about at night: what's running out there while I sleep? FrostGuard heats with a PTC ceramic element behind a steel grille. No flame, no fuel to refill, overheat protection built in, and it's ETL listed.
Treat it like any 1500W appliance and it'll treat you right: set it on a dry bench or a paver, not the wet floor, keep it clear of anything that can fall on it, and never cover it.
Don't Take Our Word for It. Point a Thermometer at It.
Plug it in, and the ceramic element is up to heat in about 3 seconds. Hold your hand at the grille, or aim an infrared thermometer at it and watch the reading climb. Then tilt the stand to aim the heat straight at the bench that worries you most.
$149.95 during the Black Friday Sale, down from $199.95, with free shipping. That's the heater, the thermostat and the probe. Thirty fresh geraniums from the garden center in May cost more than that, and none of them would be the cuttings you've kept going for fifteen years.
Sized honestly: it's made for a small hobby greenhouse, a lean-to, a sunroom or a grow tent. Bigger or single-wall spaces need two units, two probes, two numbers.
A 1500W PTC ceramic greenhouse heater that ships with a digital thermostat and probe. It reads the temperature beside your plants all night and holds the number you set, so all thirty pots go back out to the window boxes in May.
Why 25% off? It's our Black Friday Sale, priced for growers who want the probe in the pot and the number set before the first frost warning, not the morning after it.
$149.95 during the Black Friday Sale, 25% off with free shipping and 30 days to change your mind. A probe at the roots, a number you set once, and a heater built for a greenhouse, not a living room.
Get FrostGuard — 25% Off →