Central Park Great Lawn was crowded this past Sunday, with blankets spread across the grass and coolers packed with food. But not every group looked satisfied. Watermelon slices sweated in the heat, sandwiches wilted, and more than one group forgot a corkscrew.

Summer picnics are in full swing across city parks. But conversations with picnickers this week turned up a pattern of common mistakes. Packing soft cheeses like brie without ice packs, for example, left several blankets with puddles instead of snacks. Others tried to bring elaborate salads, only to find them soggy by the time the lunch hour arrived.

Timing was another issue. Many arrived at Prospect Park after 1 p.m., only to find all the shaded spots already claimed. "We should have come earlier," said Jane Lee, a teacher from Park Slope, as she repositioned her group into a sliver of shade.

Several groups mentioned a lack of trash bags. By mid-afternoon, bins near Sheep Meadow overflowed, and some visitors quietly packed out their waste. Others left behind wrappers, drawing the attention of Parks Department staff making rounds at 4 p.m.

For those heading out this weekend, city regulars suggest ice packs for cheese, simple sandwiches over salads, early arrivals for shade, and extra trash bags. Park rules still prohibit alcohol, but enforcement varies by location and hour. As temperatures rise, shade and hydration matter more than ever.