ST. PAUL — Watching grocery stores spread is usually like watching ice cream melt.

By that standard, Hy-Vee Supermarkets is on a fast boil — on track to have 12 supermarkets in the metro area by the end of next year.

Already, Hy-Vee has become one of the area’s biggest supermarket chains in only three years.

“We are thrilled to have Hy-Vee,” said Dan Buchholtz, administrator of Spring Lake Park, which will soon have a Hy-Vee at Minnesota 65 and 81st Avenue.

“I think Hy-Vee is being heartily welcomed wherever they go,” said Buchholtz.

The Des Moines-based chain launched its invasion of the metro area in 2015 with a store in New Hope. Other stores quickly followed in Oakdale, Eagan, Lakeville, Cottage Grove, Brooklyn Park, Savage and Shakopee.

A Hy-Vee spokeswoman would not answer specific questions about the company’s plans, but confirmed by email the fall opening of stores in Robbinsdale and Plymouth.

Hy-Vee has not yet picked a date for the grand opening of the Spring Lake Park store, but administrator Buchholtz said it would be soon. The store is across…