Often when we think leafy greens, we think about kale, collards, cabbage etc… But outside of your garden, some leafy weeds like dandelions, nettles, or purslane, when picked young and without any chemicals added, are tasty too. If you move further away around the world, some shrub-like plants such as the bitter leaf (Vernonia amygdalina) or tree-like as the moringa knowa here know as the horseradish tree (Moringa oleifera) have good, tasty leaves to eat as well.
Closer to Maryland, the white mulberry tree (Morus alba) is a way for you (and the livestock!) to eat more greens. According to www.livestrong.com, the young spring leaves are edible and The American Diabetes Association notes that mulberry leaves may reduce blood glucose levels for the treatment of Type 2 diabetes.
Unlike the groundhog I found in our white mulberry tree chewing leaves, I think I will skip the leaves and go directly to the berries.