Whats too hot for a hoop house?
 

[COLOR=black][FONT=Arial]Hi, I'm new here. This is my first time posting. I live in Northern Ohio. I started seeds indoor on April 9th and they have been outside in my 2 1/2ft W x 3ft T x 5ft L hoop house. My thermometer sits on the grass next to my plants and I am sure this affects the accuracy of its ready. On days when it’s in the 60s but clear the temp inside reads 120F! It doesn't feel that hot. I keep them watered and the plants LOOK GREAT! But I am wondering if those temps will cause the plants to some how not produce once planted out. So my questions are...Is this to hot? and Will this make them sterile some how?[/FONT][/COLOR]

Not an expert but I think the plants will be ok and future buds and blossoms, too, but any pollen exposed to those temps would be affected and any blooms would drop as a result of not being successfully pollinated. At one month old that's probably not an issue yet. Those temps are much higher than ideal for tomato plant growth. Can you open an end to ventilate a bit during the day? How much longer are you going to keep growing them inside? Not sure where you are in Ohio, but the temps here in sw PA are going to be conducive to allowing plants to be outside after tonight's low of ~ 43.

I agree 100% with Kath who suggest that it's probably a good idea to remove your plants from the tunnel now that temps have started to stabilized. While raising the minimum temperature is important, keeping the maximum temperature from exceeding a range optimum for crop growth is equally important. Since tunnels are passively vented through sidewalls and endwalls, air temperature and humidity can affect crop growth, nutrient and water uptake, pollination, fruit ripening and pest outbreaks.

Thanks for the advice. I opened the tunnel this morning at 8:45 and the thermometer already read 100 in the sun. Our nights are still pretty cool here in Northern Ohio. Last night it was around 40. I hope they make it. I have promissed some to my cousin and aunt am worried now that they aren't more then just a funny looking grass. LOL. It was my cousin that first suggested that the temps were HIGH. Looking at their size after all this, and compairing to photos of plants as far along makes me wonder if mine are doing as well as I thought We all might just end up haveing to buy some plants just to be safe. Will learn from my mistakes and do better next year. Thanks again for the help.

I don't know where you are in Ohio, but tomatoes can make amazing amounts of growth in a week so you should still be alright.

The ground has a cooling effect. 120 is high, I get concerned at 90F. You said your plants look healthy, so they should be ok. Just make sure you vent when the sun shines.

Can you access the trays easily enough to bring them out in the day and just put them back in the late afternoon or are these planted in ground already?

Put about 20 to 50 --1 gallon milk or tea jugs filled with water in the hoop house on the ground along the edge.. The water will keep the temp down near the plants and keep them warmer at night! this works great and can also be used to water the plants if you have extra ones! Five gallon buckets work great too but the clear plastic gallons let the light through! .Whoite containers will reflect the light. another little trick is put perlite on the ground to reflect light up under the leaves! Leave some of the caps off the gallons to give extra moisture to the new plants!