The most common letter we get goes something like this. "I love what you're writing, but I rent a one-bedroom apartment with a north-facing kitchen window and no balcony. None of this applies to me."
It does, though. Here are three things, in escalating order of effort.
One: a single pot of one native plant.
Even on a windowsill that gets only a few hours of indirect light, you can keep one pot alive. Pick one plant. Just one. We'd recommend native columbine (Aquilegia canadensis) for low light, or wild geranium (Geranium maculatum) for partial light, or black-eyed Susan (Rudbeckia hirta) for any window with three or more hours of direct sun. The plant doesn't have to live forever. It has to live for one growing season.
If you can crack the window open during bloom, pollinators will find it. They will find it sooner than you think. Native columbine is specifically pollinated by ruby-throated hummingbirds, which migrate up the East Coast every spring and which are hungry. We have known city-dwellers who saw their first hummingbird ever, in their lives, after putting one columbine on a fifth-floor windowsill.
Two: a window box, with three plants.
If your window has an exterior sill or a railing you can attach a box to, this is the bigger move. A window box gives you about six square feet of growing space, which is enough for three plants and enough biodiversity to actually function as a small habitat.
The mix we'd recommend, for a sunny window: one Rudbeckia, one Asclepias incarnata (swamp milkweed, which thrives in the constant moisture of a small box), and one Symphyotrichum (aster). That's an early-summer bloomer, a host plant for monarch caterpillars, and a late-season nectar source. Three plants. Six square feet. A small functioning food web.
Window boxes have one logistical thing to know about: they need to be watered more often than ground gardens, sometimes daily in summer heat, because they have less soil and less root mass to hold moisture. If you travel a lot, this might not be the right move. If you're home regularly, it's fine.
Three: one minute of looking, every day.
This is the one that actually matters most, and the one that costs nothing.
Stand at your window every morning, with your coffee, and look at whatever is outside it for one minute. The strip of city tree on your sidewalk. The rooftop across the alley where pigeons gather. The single weedy planter outside the bodega. Whatever's there.
You will start to notice things. The same starling on the same wire, every morning at 7:14. The way the sycamore three buildings down loses its leaves three weeks before the maple next to it. The day the first spring bee shows up in March. The night a peregrine falcon, which lives on the ledge of the building across the avenue, comes home with a pigeon in its talons.
This is, despite appearances, a real ecological practice. People who do it report knowing their neighborhood differently within a few weeks. They start to see seasons in places they used to think were seasonless. The minute itself is mostly free. The change it produces in you, given a year, is real.
You don't need a yard. You need a window, a pot, a box, and a habit. In that order, or in any order. Start where you are.
— The editors