


PSA for everyone itching to get their pepper plants outside right now.
I get it — the days are warming up, the seedlings are looking good, and every instinct says get them in the ground. But if you're growing Capsicum chinense (reapers, ghosts, scorpions, 7 pots — anything superhot), nighttime temps in the 30s are still a real threat even when the forecast looks borderline.
We ran a little experiment in our commercial nursery last night during a near-freeze here in upper East Tennessee. Two dataloggers — one uncovered, one under a single layer of 1.5 oz floating row cover over a tray of chinense seedlings.
Uncovered: 32.8°F overnight minimum
Under row cover: ~38–40°F
Delta: 5–6°F
That gap is the difference between a healthy transplant and a plant that never fully recovers. Chinense starts accumulating chilling injury below 50–55°F with extended exposure. Below 32°F you're looking at irreversible cell damage within the hour.
This was done on nursery seedlings but the concept applies exactly the same to plants in the ground or outside in containers. A single layer of row cover, sealed at the edges, buys you meaningful protection on nights when the forecast is flirting with freezing.
One thing worth knowing: a forecast of 34°F doesn't mean your plants see 34°F. On calm, clear nights the canopy can run 3–5°F colder than the official air temperature reading due to radiative heat loss. Apply your cover before dusk — not at midnight. The ground heat you're trying to trap is already gone by then.
Happy Growing.
by HarmonySpringsFarmTN

6 Comments
Yeah, I’m not moving them to greenhouse till May.
I read that title wrong
I did the same thing but I just have a 4′ tunnel I pull over my seedlings. For the 32F nights I add fleece like you did assuming it adds 5 degrees (which it seems it does!). Also confirms my suspicion that anything below 32 will get far too cold regardless of tunnel and fleece.
Nothing is stunted yet, so I hope my luck continues.
I’m itching to get mine in the ground for sure, and we’ve been having 75/50 days for a couple weeks straight. But Google keeps telling me it’s a false spring and there is almost certainly another deep freeze coming, and that mid to late April is the earliest I should do it.
My peppers (and everything else) are getting way too big to keep bringing in the house lol. This spring is going to be interesting.
We’re going in the ground in our high tunnel this week. But we do have heat options, if absolutely necessary. Our outdoor growing will start closer to first of May
Yep, Ty for sharing this data. A lot of folks don’t realise how bad sub 10c temps are for most nightshades including peppers and tomatoes. I’m in the PNW area-ish but on the Canadian side, zone 8a. I probably won’t be sending my peppers out till end may early June. I haven’t even bothered to start my tomatoes yet lol. Such a crazy warm winter but a lingering cold Spring.