My tomato plants' leaves curling up

[OaklandCityFarmer]

It's just your basic back-forth sprinkler. It varies as to when I water but always either early-mid morning or evening after the hottest time of day. We have the hot days plus hard, black dirt (I'm guessing it has a fair amount of clay). I amended a bit prior to planting but not as much as I would have liked.

What you can do also, is put out a rain gauge to help measure how much water you sprinkler is giving. A good watering even 3 times a week in really hot weather would be okay just in the morning to keep them well watered. Mulching them also goes a long way. We have clay soils here too so I feel your pain. Even after cover crops and compost we never feel we've amended enough.

So, if it's a case of too much water do I wait and let them really dry before waterin again or do I cut back gradually? I have a soaker system I have been too lazy to put together - guess I will get it going now....

Dig a little bit into the soil around the base of the tomato. It should be moist at about 4-6 inches before you start watering again. If you get to 4 inches and it's moist I would wait. When you get to 6 inches and it's dry then water. Now, this also depends on how established your plants are and how deep their root system goes. If you haven't been watering deeply then they may have roots on the shallower end. If that's the case then water at 4 inches very deeply and then give them a few days to a week depending on the soil moisture level.

Soaker systems would come in nicely here.

Good luck

 

[Broke Down Ranch]

I think I may have found another potential answer - copper deficiency. Scroll down to the image of copper deficiency and what my tomatoes are doing looks a lot like that:

http://4e.plantphys.net/article.php?ch=t&id=289