What Causes Yellow on the Leaves

Question

I just started a garden, first attempt. They have yellow leaves. We water the garden on a set time 2 times a day.

Answer 1

https://www.gardeningknowhow.com/edible/vegetables/vgen/vegetable-gardening-for-beginners.htm

https://www.gardeningknowhow.com/edible/vegetables/vgen/vegetable-gardening-advice.htm