How cold can a Tomato plant get before there is a problem?

[hardland]

I'm in Sth FL and don't expect it to get to cold
So far we have been down to 49' this week. I was curious what temp my toms can handle? Low 40's ok? Not sure how to protect them if it gets any lower than that either?

[rainbowgardener]

As usual, the answer is depends... some varieties have been bred to have more cold tolerance than others, wet cold vs dry cold makes a difference, etc. Also are you just concerned about the plant surviving or the fruit? If temps get below 50, it is likely to drop blossoms instead of setting more fruit. But it won't drop fruit that are already set. If the plants are protected and have been getting used to the cold gradually (a sudden cold snap when it's been warm is worse than gradually cooling temps), the plant should survive temps down into the upper 30's. I think the best protection is clear plastic over hoops or some kind of frame (so the plastic doesn't touch the plants), but row cover works too.

[url=https://growerssolution.com/page/GS/PROD/thermalblanket/AG125]row cover[/url]

[TZ -OH6]

They will survive anything above 32/frost, but there is often up to a 5-7 degree variation from the weather forcast dependant on local factors. My property as a whole will frost when the weather prediction is in the mid 30s over night, but my brick house retains heat so there is a ten foot halo of warmth next to the house that will not be frosted in the morning so when I am feeling lazy I will leave the seedlings out on the back porch over night when the forcast is in the upper 30s if the days are warm. I'll bring them in if the daily highs will be below 50 for a couple of days.

If you only have a couple of flats of plants such that moving them in and out is no problem I would keep them warm at night (inside if outside is in the 50s).