Plant Science & Conservation

Garden Stories

Solutions for the Frustrated Urban Botanist

How I grew a prairie on my balcony鈥攁nd how you can, too

City spaces may seem limiting when it comes to plants, but even a small balcony can become an oasis. When we moved into our condo, I turned our 5-by-10-foot balcony into my personal green space, where I can de-stress and enjoy my little piece of 鈥淗orto in Urbs.鈥

prairie on the balcony

Although there are more than 400,000 plant species worldwide, I know only a subset will survive in Chicago, especially over winter. But I also know there are more options than the common store-bought showstoppers seen throughout the city. As a self-identified plant nerd, I wanted to try to grow a native Illinois prairie on my balcony鈥攕o I set out 15 years ago to make it happen.

The challenge? 
Figuring out how to grow wild, deep-rooted prairie species in shallow containers in the middle of a concrete jungle.

pot

Spotted beebalm (Monarda punctata)

soil with sprouts

Soil

tall balconie plant

Blue vervain (Verbena hastata)

The Pot Struggle is Real

First hurdle: winter. 
Chicago winters are no joke, and pots are a tough environment for roots compared to deep and insulated prairie soil. I felt I had to be choosy with materials, knowing terracotta and brittle plastics can crack in the cold. I landed on fiberglass, and later tried steel and concrete, which I don鈥檛 recommend for balconies unless you want to test your weight limits. Deeper pots are better鈥攎ine are at least 16 inches deep鈥攁nd I always try to insulate the sides to protect roots from freeze-thaw cycles; I use pieces of styrofoam.

Getting Soiled

Next up: soil.
Illinois prairies vary based on the soil they grow in; sand prairie plants are very different compared to wetland plants. I knew I couldn鈥檛 totally recreate the complexity of prairie soils, but I tried to mimic them the best I could. I used commercial potting mix as a base and tweaked each pot to simulate different habitats, adding peat for wetland species, sand for dry prairies, even rubber bits to mimic gravelly slopes. Did I overdo it? Probably. But it was fun. In hindsight, a good potting mix would suffice for most plants. But if you want to mix it up, there are some lightweight amendments which can be added to make your soil hold more water (peat), keep it drier and more aerated (perlite), or both (vermiculite).

Plant Picks

With pots prepped, it was time for the fun part: choosing plants.
I looked for species that matched my conditions鈥攎ostly full sun, good drainage, and, because life happens, some seasonal neglect. Native tallgrass prairies are famous for very tall plants, some almost 12 feet tall. I skipped the tallest prairie species and anything too aggressive. My goal was to mix plants that were attractive, hardy, and would play well together in a confined space.

I picked species from habitats like sand prairies, wetlands, gravelly slopes, and savannah edges (a sunny forest edge). In addition to anything too tall for a pot, I avoided forest plants, since they require shade鈥攕omething my south-facing balcony was lacking. I wanted beauty, resilience, and biodiversity, all in a container garden. After 15 years of experimenting, here鈥檚 what I鈥檝e learned:

The MVPs: Most Valuable Plants

Through lots of trial and error (and meticulous note-taking, because: scientist), I鈥檝e found some real winners.

Partridge pea

Partridge pea (Chamaecrista fasciculata)

New England aster (Symphyotrichum novae-angliae)

New England aster (Symphyotrichum novae-angliae)

 

Red columbine (Aquilegia canadensis)

Red columbine (Aquilegia canadensis)

 
 

Top performers:

Partridge pea (Chamaecrista fasciculata):
a reseeding annual that鈥檚 loved by pollinators

Nodding onion (Allium cernuum):
Chicago鈥檚 namesake wild onion, dependable and pretty

Spotted beebalm (Monarda punctata):
showy, self-seeding, and a wasp magnet in the best possible way; these wasps do not attack people and have beautiful iridescent colors

Phlox (P. bifida and P. divaricata):
gorgeous blooms that are worth the effort

Aromatic aster (Symphyotrichum oblongifolius):
compact and colorful in the fall

Sedges (Carex spp.):
The real MVP. They insulate pots, support other plants, and look great year-round

Great for beginners:

Red columbine (Aquilegia canadensis)

Lanceleaf coreopsis (Coreopsis lanceolata)

New England aster (Symphyotrichum novae-angliae)

Stiff goldenrod (Oligoneuron rigidum)

Some species surprised me鈥攍ike fringed loosestrife (Lysimachia ciliata), which was both beautiful and a bit too enthusiastic. Others, like wild indigo (Baptisia) and lobelias, failed to thrive but taught me valuable lessons about plant needs, microclimates, and container life.

What I鈥檝e Learned

A few broad takeaways (which, let鈥檚 be honest, still need testing):

  • Plants that reseed themselves and come back each year are great. They act like well-behaved annuals.
  • It seems like fibrous or rhizomatous roots overwinter best in pots; tap roots, not so much.
  • Some plants can act as 鈥渘urse plants鈥 (such as sedges) and protect plants growing near them, improving pot survival by stabilizing soil and providing winter cover.
  • More native species can handle container life than I originally expected.

One of the ongoing mysteries for overwintering plants:
Does keeping the soil wet in the winter help or hurt with freeze-thaw damage? Some say wet soil freezes more slowly, while others claim that drying out soil in the fall can reduce damage. I鈥檓 still figuring it out鈥攂ut leaning toward dry.

butterfly

Phlox (P. bifida and P. divaricata)

In the End

Gardening is experimentation.
Some plants will fail, and that鈥檚 okay. Others will thrive and surprise you. What matters most is creating spaces that invite life鈥攂irds, bees, and a little biodiversity鈥攂ack into our urban world.

If you're a fellow frustrated botanist, or just a curious gardener, I hope my balcony experiments inspire you to try some native plants in your space. Start small, stay curious, and don鈥檛 be afraid to fail. The plants, and the pollinators, will thank you.