In the brown March garden, there are small and exciting signs of wild botanical life. In Harlem last summer I was thrilled to discover a nettle plant growing in a blueberry bush's pot. I don't know how it got there; perhaps the seed was in the soil when the blueberry was field dug by its growers, in New Jersey. Perhaps nettles I collected shed seed, but don't think so. But there it was, and I allowed it to grow fat in the pot.
When we moved to Carroll Gardens I planted it at the back of our new garden, near a stand of existing Solomon's seal (Polygonatum odoratum var. pluriflorum 'Variegatum' - such a mouthful). And now it is up. They are delicious, and full of flavor. Also hard to find, locally. I only know of one nettle patch in Manhattan. Now two. If you grow nettles snip the mature stalks before or when they set seed, to control their spread. And you can harvest the spring leaves repeatedly. Blanch in boiling water to de-sting them.
Ha! Also hard to find (if you are a city forager): indigenous sweet fern, Comptonia peregrina. Not a fern at all. It has a very strong scent which I love, and I cook with it as often as I can. I have two shrubs, now, both developing catkins, having made it through winter as well.