Often.

Long soakings.

Side dress with nitrogen.

We have 90 to 100 heat for over a month. I water the corn every day and I use Miracle grow. My corn is about four feet now. From my experience I get good corn when I thin it to about 1 1/2 foot. When my corn was crowded the production was bad. Last year I got two per mostly each plant. My problem with raising corn are the rabbits. They love to snack on my corn.

this is how it looks

does it need more fertilizer?

I use a soaker hose and never let it get really dry. If we don't get an inch of rain, I soak twice a week. Early corn is ready, main crop just tasseling. I make liquid fertilizer by mixing organic fertilizer with water, letting it steep for 3 days, then sloshing it on. The corn gets a big drench of the stuff at tasselling.

When it isn't raining, I water every 3 days. I just picked the last of the 3rd planting and the fourth is coming on. The fifth is beginning to silk. The sixth...you get the idea.