You can find ripe and ripening dewberries all over the arboretum. Most of them are weeds that need to be removed. But there are also several larger, established, and fully-sanctioned patches, like this one near Mickle Hall.
Dewberries are similar to mulberries, which are also available this week. The dewberry is pictured left. The red mulberry is pictured right. The red mulberry is basically ready to eat. The dewberry needs time to ripen. Both berries taste best when black. It's advisable to wash dewberries before consumption.