Help!! yellow leafs at the bottom

[Dizzworth]

I am having some problems in my outdoor garden I have never seen before! I will try and post pics later. The outside of the plants look very healthy and green but when you look underneath the plant there are constantly leaves turning yellow and dieing at the bottom and inside the plant!? It seem to happen pretty frequently. What the hell could could be the problem. Any input would be great!

 

[Seamaiden]

Heat, growing and using up nitrogen so taking it from the areas that it can, lack of food. Those are three things that can cause rapid yellowing.

 

[tjrasta]

i plant at the middle of march and notice the old leaves die off when she starts to flower, but like Seamaiden said, its really hot here, and that might be doing it