I have two miniature sunflower plants on my porch,the top heads seem to be dieing but new buds?

Question

seem to be growing,is this normal? How often should I give them water?

Answer 1

If they are "on" your porch as you say, I'm assuming they are in pots. This is a mistake, since sunflowers of any size have very deep root systems.  Get them into the ground as soon as you can.  They need lot of sun, water and fertilizer to do their best.