Hazel Dell — Carlos and Rafael Perez-Mercado aren’t spending their entire summer playing. The two have been volunteering their time at the Churches in Partnership Community Garden at the Heritage Farm on 78th Street. The boys have been hoeing onions (and other veggies) and harvesting squash and other fresh produce. Carlos, 13, goes to Discovery Middle School and Rafael, 10, attends Washington Elementary School. Food from the gardens goes to local food banks. Last year, with help from volunteers, the Heritage Farm produced nearly 19,000 pounds of food.