Determining Depth of Field

On my belly in the damp grass I had the greatest time shooting what I thought were perfect close-ups of my precious find.  But once uploaded, I realized the DoF was too shallow.  I wanted the entire flower in focus, all the way out to the petals.

On my belly in the damp grass I had the greatest time shooting what I thought were perfect close-ups of the tiniest violets.  But once uploaded, I realized the DoF was too shallow.  I wanted the entire flower in focus, all the way out to the petals.  But every shot lost the crisp edge of the petals, which is what I was hoping for.

This is where I am confused about the camera settings, the choice of lens and the length of the lens.  I was about as close as I could be to my tiny subjects and was resting the camera on the ground.  Perhaps distance also comes into play.  Too many variables . . . I am disappointed.

The flowers won’t last much longer. But then again, they will be back next. I saved some seeds and sprinkled them in the same area. Fingers crossed.