"Essential for" or "essential to"?

Essential can be followed by for or to, depending on what comes next.

Before a noun or noun clause, for and to are both correct, as in these examples:

• The river is essential for/to the region's economy.
• Food is essential for/to life.
• Using high quality materials is essential for/to achieving a good result. 

Before a verb, use essential to, as in these examples: 

• It is essential to use the proper technique.
• It's essential to arrive on time.

I hope this answers your question.