Entrepreneurs seeking the resources needed to launch sustainable clean technology companies should circle May 1 on their calendar.

That’s when applications are due to the annual Cleantech Open, a five-month accelerator program that offers participants training, mentoring, funding and publicity, as well as prize money.

The program culminates with nine major events across the country, including a summit in Minneapolis.

Cleantech Open was founded in 2006 and has helped more than 700 companies.