The Heater Ran All Night. The Tomato Seedlings Died Anyway.
Five reasons gardeners are carrying the house heater back inside this winter, and plugging in one that reads the temperature beside their plants 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, ran the cord, turned it up, and went to bed thinking the seedlings were covered.
Then the morning. Leaves gone dark and glassy. Every tray of tomato and pepper starts flopped over in its cells. And the heater, still sitting right there, still plugged in.
That's the part that stings: you didn't forget. You protected them, and they died anyway. But the seedlings weren't lost because you did something wrong. They were lost because that heater was built for a completely different job.
A House Heater Is Built to Warm People. Your Plants 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 seedlings above 50." 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 trays by the glass sit several degrees colder.
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 plant needs | 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 soil beside the plant you're most worried about. Set your number. That's the whole setup. Here's the night now:
| Time | Greenhouse | You |
|---|---|---|
| 9 pm | Probe reads 55. Heater waiting. | On the couch. |
| 2 am | Drops below 50. Heater fires. | Asleep. |
| 2:20 am | Back to 50. 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 seedlings. |
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 seedlings nearest to it while the far corner still freezes. FrostGuard holds a floor: it only adds heat until the probe reads your number, then stops. Warm enough for the seedlings, 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.
$119.95 during the Black Friday Sale, down from $199.95, with free shipping. That's the heater, the thermostat and the probe. Less than restarting every tray from seed, and a lot less than losing six weeks of the season.
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 the seedlings you started in February make it to planting day.
Why 40% 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.
$119.95 during the Black Friday Sale, 40% 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 — 40% Off →