Patches without ground.

Part I

A balcony is a patch.

7 min read

For most of the writing about backyard ecology, the implicit reader has a backyard. They have a strip of lawn between the house and the sidewalk, a few square feet of dirt where the back deck meets the fence, room for a tree if they wanted one. Most of the books, most of the websites, most of the well-meaning recommendations are written for that person.

This Issue is for the other person. The one who lives on the fourth floor of a building in Queens. The one whose entire outdoor space is a 4×6 concrete balcony with a metal railing and exactly enough room for two folding chairs. The one whose only exposure to ground is the strip of dirt around the tree on her sidewalk, which the city manages and which she has no control over.

The first thing we want to say is this: that 4×6 balcony is a patch. It is a place where things can live. Pollinators will find it. Birds will visit it. The choices you make about what goes in your two terracotta pots are not less consequential than the choices a suburban homeowner makes about what goes in their half-acre — they are differently consequential, and at the right scale of ambition, they matter.

Here is the case, in three parts. One: the city is full of pollinators that are starving. There are over 250 native bee species in New York alone, plus migrating monarchs that pass directly through the dense cores of every East Coast city, plus hummingbirds that stop in window boxes every September. None of these are getting enough late-summer nectar from the existing landscape, which is mostly grass, ginkgo trees, and ornamental flowering shrubs that produce little to no nectar.

A single pot of native asters on a fourth-floor balcony, in late September, is a meal. We are not exaggerating. Pollinators have been documented finding nectar sources from over a kilometer away, navigating to specific window boxes by scent. Your balcony is not, from their perspective, far up.

Two: vertical density adds up.

An apartment building with twenty units, half of whom keep one or two pots of native plants on their balconies, is functionally a small pollinator garden distributed across forty feet of vertical space. From the perspective of a passing bee, that's a city block of habitat where there used to be none. Multiplied by the number of buildings on the block, the number of blocks in the neighborhood, the number of neighborhoods in the city — you start to see the scale.

The reason this isn't already happening at scale is not lack of interest. It's that nobody has told most apartment-dwellers that they count. Ecology writing has overwhelmingly been written for and addressed to people with yards. If you've ever felt vaguely guilty reading articles about native plants because you don't have anywhere to plant them, this Issue is the correction. You have somewhere. We're going to tell you what to do with it.

Three: the practice itself is good.

The third reason is the most important and the hardest to argue for, which is that the daily small practice of tending something living, on the small bit of ground you have access to, and watching what shows up, is good for you. Not in a wellness-industrial-complex way. In a real way. The people who do this report less anxiety. They sleep better. They notice things.

The bee that arrives at your window box on the first warm day of April is not a scientific event. It is a small piece of news that the world sends you, in your kitchen, on a Tuesday morning. Without the pot you wouldn't have gotten the news. With the pot you do. Multiply by a year of mornings and you have a different relationship with the place you live.

That is the actual argument. The biodiversity stuff is real, and we'll talk about it. But underneath all the species counts is a simpler claim: you have a patch. The patch is not too small to matter. Putting living things on it changes you, and it changes the ecology of the place where you live, and these two things are the same thing.

Part II

What grows in a pot, what doesn't.

8 min read

The bad news first: not everything grows in a pot. The good news: more grows in a pot than you've been told.

Most "balcony gardening" articles you'll find online are written for someone whose goal is decorative — they want a colorful balcony for cocktail-hour Instagram. Those articles will tell you to grow petunias, geraniums, and impatiens. All three are non-native to North America. All three feed essentially nothing. They are the container-garden equivalent of a Bradford pear: visually busy, ecologically empty.

What we want is different. We want plants that grow happily in containers and feed something. The list is shorter than the decorative list, but it's not short. Here are the categories, in rough order of how easy they are to keep alive.

The forgiving ones (start here).

If you have never kept a plant alive before, start with these. They tolerate a wide range of light, recover from a missed watering, and bloom long enough that you'll see results.

• Black-eyed Susan (Rudbeckia hirta). Native across most of North America. Sunny yellow flowers June through September. Native bees love it. Goldfinches eat the seeds in the fall if you leave the heads up.
• Coreopsis (Coreopsis lanceolata or C. verticillata). Drought-tolerant once established. Long bloom season. Small native bees and hoverflies are constant visitors.
• Native salvia (look for Salvia azurea or your regional equivalent). Hummingbirds will find it from blocks away. Tolerant of neglect.
• Bee balm (Monarda). Smells incredible. Hummingbirds, native bees, butterflies. Spreads happily; eventually outgrows a pot but takes its time.

The ones with one specific job.

These plants exist for a single reason: they feed one specific group of pollinators that nothing else feeds as well. The yield is high but the plants are sometimes fussier.

• Common milkweed (Asclepias syriaca) or swamp milkweed (A. incarnata). Without milkweed, no monarchs — it's the only host plant for their caterpillars. Swamp milkweed actually prefers a pot to a yard, because pots stay moist. Plant one. You will, with high probability, have monarch caterpillars on your balcony in late summer.
• Native asters (Symphyotrichum in the East). Late-bloomers — September into October when nothing else is flowering. The most important late-season nectar source for migrating monarchs and native bees. Plant alongside goldenrod for a pollinator banquet in October.
• Goldenrod (Solidago). Pick a smaller-statured species like S. speciosa for a pot. The most valuable late-season plant in the eastern food web. Plant it.

What about herbs and edibles?

A common question. Most culinary herbs — basil, oregano, thyme, sage, rosemary, mint — are non-native to North America. They are not, however, ecologically empty. Once they bolt and flower, many of them are excellent nectar sources, particularly for honey bees and small native bees. Oregano in flower, on a sunny balcony, is one of the most active pollinator surfaces you can keep. Let your herbs bloom. The rule against non-natives is about structural habitat — what hosts caterpillars and feeds the food web. Herbs that bloom at all add to the nectar supply, which is real value.

Vegetables are a different question. Tomatoes, peppers, beans — mostly non-native, and pollinated by very specific native bees (bumblebees, in the case of tomatoes). They're fine to grow alongside the natives. They just don't count as habitat in the same way. Grow them because you want tomatoes, not because they help the bees.

What doesn't work, and why.

Some things just won't survive in a container. Trees, mostly — and we know that's the painful one, because the previous Issue made the case for oaks. An oak can technically live in a container for a few years. It can't thrive. It will get root-bound, decline slowly, and eventually fail. If you want to plant an oak and have a balcony, the answer is to find a community-garden or schoolyard partner. Don't try to grow an oak in a five-gallon pot.

Native shrubs — viburnums, blueberry, serviceberry — are similar. They want more root room than a pot can give them. There are dwarf varieties bred for containers. They host less than the full-sized versions but more than nothing. If you have the budget and a really big pot (24 inches across, minimum), they're worth trying.

That last line is worth pausing on. A 14-inch pot of native asters and goldenrod, on a fourth-floor balcony, is feeding more native bees per square foot than the average American lawn. Lawns are deserts. A balcony pot of natives is an oasis. The math really does work that way.

Part III

A small how-to: your first three pots.

7 min read

This part is for someone who has decided to actually do this and wants a specific shopping list. Three pots, three plants, one weekend. The whole project, including buying the pots and the plants, can be done for under $80 and one trip to a garden center.

The recommendation is three pots because three is the smallest number that gives you a real ecological yield. One pot is fine, two is better, three is the threshold where the balcony starts to function as a small habitat — nectar across multiple bloom windows, host plants for at least one species, structural variation that gives small insects places to hide.

What to buy.

The pots. You want three pots, each at least 12 inches in diameter and at least 12 inches deep. Bigger is better; the plants will be happier. Terracotta is classic and breathable but heavy and prone to cracking in winter. Glazed ceramic is heavy but durable. Plastic is fine and forgiving and the plants do not, in our experience, mind. Whatever you buy, make sure it has drainage holes. A pot without drainage holes will kill any plant in it within weeks.

Budget: $30-50 for three medium pots from a garden center, less if you can find them at a thrift store or on a free-stuff website.

The soil. Buy bagged potting mix, not garden soil. They're different products. Potting mix is designed to drain and to not compact in containers. A 16-quart bag from a hardware store will fill three medium pots and runs about $10. We don't have a brand recommendation; the cheap stuff works fine.

The plants. Buy these from a native-plant nursery if there is one within driving distance. If not, ask at your local independent garden center which of their plants are native to your region — some staff will know, some won't, and you should buy from the ones who do. As a last resort, online native-plant nurseries ship through the mail; the plants arrive small but establish quickly.

The three plants we'd pick.

For an east-coast balcony with at least four hours of sun a day, this is what we'd buy:

Pot 1: Black-eyed Susan (Rudbeckia hirta). Reliable, beautiful, blooms June through September. The pollinator workhorse of the early-summer balcony. ~$8 for a small one-gallon plant.

Pot 2: Swamp milkweed (Asclepias incarnata). The host plant for monarch caterpillars, and the only one that thrives in containers. Plant this and you have, in our experience, a meaningful chance of monarch caterpillars on your balcony in August. ~$10.

Pot 3: New England aster (Symphyotrichum novae-angliae). Blooms September through October, when almost nothing else is. The most important late-season nectar source for pollinators in the East. ~$10.

Total plant cost: ~$28. Plus pots, soil, and a small bag of mulch (optional but nice), the whole project is under $80.

How to plant.

Fill each pot two-thirds with potting mix. Take the plant out of its nursery container by gently squeezing the pot and tipping it; the plant should slide out with its root ball mostly intact. If the roots are tightly circling the bottom, gently loosen them with your fingers — this is called "teasing" the roots and it helps the plant establish faster.

Place the plant in the new pot so the top of its root ball sits about an inch below the top of the pot. Fill in around it with more potting mix. Press gently to remove air pockets but don't compact the soil hard. Water until water comes out the drainage holes.

That's it. The plants are now in pots and the pots are now on your balcony.

What happens next.

In the first week, the plants will look a little sad. Transplant shock is real and brief. Water deeply when the top inch of soil is dry — this might be every day in summer heat, every two or three days in cooler weather. Don't water on a schedule; water when they need it.

By the end of the first month, the black-eyed Susan will probably be flowering, and the first bees will arrive. They will arrive sooner than you think they will. Pollinators are looking for what you've planted; you don't have to wait for them.

The milkweed will look unimpressive most of the summer. Then, in late July or August, you may notice small striped caterpillars chewing on the leaves. Don't kill them. Don't move them. Don't do anything. Watch. Over the next two weeks they will grow large, then disappear into pupae somewhere on your balcony, and a week or two after that, monarch butterflies will emerge and fly south.

The aster will come into its own in September. By then you will be looking at your balcony differently. Three pots ago, it was a balcony. Now it is a place where things live. The shift is permanent. You won't go back.

That's the whole project. Three pots, one weekend, under $80. The balcony you have is a patch. The patch matters. Plant the things, watch them work, and let us know what shows up.