september 21, 2024

I went up to the roof this morning to check on the plants and was delighted to find our bush in the southwestern corner is blooming flowers. I was already happy with its green foliage, so this development is even better.

Aromatic Aster / aster oblongifolius 'October Skies'

starting a rooftop garden

We moved to a brownstone street in March, and our apartment comes with a rooftop. It was completely empty when we arrived: expansive (~500 sqft) but barren. I started building a garden a month and a half ago, and, after a little bit of thought, decided to record my journey here.

Here's an early photo of the rooftop when we built the dining table at the beginning of summer. The roof spans both bedrooms in our apartment, which is to say that there is a lot of room on the roof. The dining table feels lost despite being 70" long!


From the other end, you can see a bit of the Manhattan skyline. The trees on our street cover the front windows of our apartment. It's lush and calming and completely private.


Neither of us are gardeners, so building out a garden didn't initially cross our minds. Instead, we got a mini charcoal grill and barbequed a few times with friends during the summer:


catching the bug

We've been trying to be more intentional about how we spend our free time, and one thing we've started doing is to spend a few minutes on the roof first thing after waking up. The morning bit is somewhat a function of nature—it's too hot in the afternoon to go up there in the summer—but it's become part of our morning ritual over the past few months.

I initially thought I'd hire a landscaper, but I'm the sort of person who can't wait that long for things so I decided to buy a few pots and try it myself. I really know nothing about gardening and certainly nothing about gardening on a roof in a place that has four true seasons, so I asked ChatGPT for some tips to get started. Here's what it recommended:


With ChatGPT's recommendations in hand, I made my way to Outside Space Garden Center in Fort Greene. I figured it's better to buy local plants versus off the internet, since local nurseries would only carry plants that do well in our climate(?). Here's what I picked up with the help of the garden staff—I was looking for drought tolerant (there's no hose on the roof, so I fill my watering can in my apartment), and perennials (returns year after year):

  • Russian Sage / perovskia atriplicifolia: Silver-grey, fine-textured foliage. 3-4' tall. Spikes of blue flowers July-September. Full sun. Drought tolerant. Deep resistant. Attracts butterflies. Low maintenance and long lived. Mixes well with Rudbeckia, Echinacea, Sedum. Zone 4.

  • Sand Love Grass / eragrostis trichodes: Produces a dazzling haze of beige seed heads tinged purple softening to tan later. August-March. 3-5' tall. A warm season grass growing in leafy, fountain-shaped clumps. Full sun. Drought tolerant. Deer resistant. Self sowing. Midwest US native. Zone 4.

  • Calamintha nepeta 'Montrose White': Clear white flowers, June-October. 18-24" tall. Mint scented leaves. Full sun, well-drained soil. Drought tolerant. Deer resistant. Attracts butterflies. Easy care. An improved variety with self-cleaning flowers and upright habit. Accent, edger, groundcover, garden borders, containers. Zone 5.

  • Sedum 'Autumn Joy': Green "broccoli" flower buds turn pink, open pink and fade to maroon August-October. 24" tall. Full sun, well-drained soil. Drought tolerant. Seed heads add nice winter interest. Long-lived. Attracts butterflies. Garden borders, containers. Zone 3.

  • Switchgrass / panicum 'Prairie Dog': Upright blue grass selected for its strong short form and brilliant red fall color. 3-4' tall. Cloud like panicles start July and carry through to November. Full sun. Drought tolerant once established. Can withstand snowloads. Selection of a northeastern US native. Zone 4.

(Make sure to wear bug spray when visiting a nursery if you're susceptible to bug bites.)

I got my planters at Home Depot. If you live in Brooklyn, they offers $10 next day/scheduled delivery, which is very convenient sans car. I used this instead of trying to haul the soil home.

This was the first corner I built: it may not look like much, but this was ~$200 and multiple hours of repotting!


Our rooftop immediately became friendlier and more inviting. There are fewer lantern bugs, and bumblebees now visit our roof. Life feels bucolic when our grasses wave in the breeze.


Last weekend, I filled out the other corner. Here's what I planted on the southwest side:
  • Wild Indigo / baptisia australis: Violet blue flower spikes. May-June. Attractive foliage. Large bushy habit. 3-4' tall. Full sun-light shade. Drought tolerant. Deer resistant. Good cut flower. Excellent in mixed borders. Plant low growing groundcovers around them as a compliment. Long lived: Northeastern US native. Zone 4.

  • Aromatic Aster / aster oblongifolius 'October Skies': Dark, sky-blue flowers. September-October. 18" tall. Full sun. Drought and poor soil tolerant. Deer resistant. Attracts butterflies. Suitable for a use as a groundcover and in mixed borders. Northeastern US native. Zone 3.

  • Sedum 'Matrona': Pale pink umbel flowers. August-October. 28-30" tall. Blue-green foliage with burgundy stems. Flowers preserve into attractive seed heads for winter interest. Full sun, well-drained soil. Drought tolerant. Long lived. Attracts butterflies. Garden borders, containers. Zone 3.

  • Catmint / nepeta 'Amelia': Pink flowers. May-August. Aromatic leaves. Mounded habit. 15-18" tall. Full sun, well-drained soil. Low maintenance. Small to med-scale groundcover, pathway edger, accent plant, underplanting for roses. Deer resistant. Attracts butterflies. Drought and seaside tolerant. Zone 3.

  • Fragrant Sumac / rhus aromatica 'Gro-Low': Low, spreading shrub. 18-24" tall x 6-8' wide. Glossy green foliage turns orange-red in the fall. Yellow flowers April-May. Red berries in the fall persist through winter. Full sun-light shade. Drought tolerant. Salt tolerant. Attracts birds & butterflies. Excellent for massing, erosion control. Northeast US native. Zone 4.

  • Fountain Grass / pennisetum 'Hush Puppy': Lasting pink plumes held high above rounded mounds of slender leaves. June-October. Only 24'30" tall. Sterile variety, will not self-sow. Useful as an ornamental specimen or in mass planting. Full sun-part shade. Drought tolerant. Deer resistant. Zone 5.

I'm spending more time up there now that the weather's cooling down. I listen to music and eat breakfast and drink tea or coffee and journal or read and answer emails and think about things. Sometimes I just sit.

what's next

I think I'm done for the season—since I'm new to gardening, it's probably best to take these things slow. I'll focus the rest of the year on learning their rhythm of watering and preparing them for winter.

I already know what I'd like to do in the spring, though. I'd like to fill out the wall between the two corners. I'm thinking about long planters and some hanging planters along the rails: they could hold annual flowers or herbs and vegetables if I want to get into vegetable gardening. We'll see! 

If you have any tips for rooftop gardening in the Northeast, let me know in the comments or email the first three letters of my name at my domain. Thanks for reading!