Just been in the garden, right now temps are 40ºC (104ºF) and 13% RH under the sun. You are right that soil is pure clay but it's totally dry, 4in down fells a little bit more wet than surface but still dry.
Does this curling usually happend when hot and humid ?
Coz I live close to the sea and I don't know if maybe during the night the RH goes up. Beside this tomatoes I also have radish which don't have drip system and I water just manually with a pipe so I guess it gets wet every time I water. Also I always water at sunset more or less, would it be better to water in the mornings with this weather ?
Thanks for the helpyes, i think its the heat
Thanks Ryan, I'll try to water in the mornings this week and see if there are any improvements.Always water in the morning! so the plant wont grow mold or fungi. when watered at night the leafs may not dry completely giving mold & fungi a chance to grow.
I don't know where you live but 13% RH is extremely low. compared to where i live. My RH is always higher then 50% all year and peaks to 80-88% in summer.
They must be curling due to lack of humidity. Try misting the leafs in the morning before the sun is in full blast.
That's the humidity I've got at home right now, 40% so no way I'll have that in the garden during the day. But I guess if I can keep the soil more humid the tomatoes will probably be able to use that water for whatever they need itI just looked up ideal humidity for toms and its 40-60 %