When we decided to build an intensive green roof, we knew it would require irrigation, fertilization, and regular, ongoing maintenance as well as many decisions about crop selection and other important issues.
In February 2015, in advance of our first growing season, the Umbrella House Garden Committee began meeting to work out the details of implementing our garden.
The discussion was intentionally framed to imagine the best use of our new growing space. We made lists of our favorite region-appropriate crops and explored possibilities for sharing the produce. We decided that we wanted an open planting area instead of individual plots and that all building residents would be welcome to gather and eat from the garden.
In this key meeting each member lent clarity to our shared intention: to transform an underused part of the building into a sustainable growing space for healthy food and community, and to do so as a model for other buildings in New York City and beyond.
Our contractor provided 8″ of engineered growing medium after completing construction of the rooftop planting bed. We used a soil mix from Long Island Compost, which met German FLL-Guidelines for green roofs.
Before planting, we applied 75 pounds of organic fertilizer to the entire garden bed. The fertilizer was raked into the planting medium and allowed to set for two weeks.
As an HDFC limited-equity co-op we qualified for GrowNYC’s Open Space Greening Program plant sale. We were able to get 11 flats of 40 plants each at a wholesale price. As everything about our garden was new, we wanted to have the advantage of planting established plants and decided to use starter plants for our first season.
We made our crop decisions based on the committee’s “dream list” tempered by what GrowNYC offered and what would likely thrive on a hot NYC roof.
Our GrowNYC order included swiss chard, broccoli, white onions, eggplant, okra, spinach, lettuce mix, zucchini, basil, tomatoes, dill, rosemary, thyme, coriander, yarrow, marigold and purple coneflower.
We supplemented this order with arugula, sugar snap peas, jalapeno peppers, lamb’s quarters, heritage tomatoes; as well as medicinal plants: hyssop, lemon balm, chamomile, calendula, and passion flower.
We began planting on Saturday, May 2nd. Many Umbrella House members, both those actively involved with the garden planning and those who were not, came to help.
Our “roof-grade” soil mix was very rocky (for better drainage and to reduce soil weight), so we raked out and removed some of the biggest rocks. While planting we mixed in additional compost to the fertilized planting medium in order to give our plant starts’ root-balls a nutritional jumpstart and a bit of extra cushion.
Nearly all the GrowNYC plants fit into the rows, and we left space for a few crops we’d recently started from seed: pole green beans, beets, kale as well as more arugula and cilantro.
We installed a drip irrigation system to water with more efficiency – both in terms of water waste and human time. The watering schedule will likely be in flux during the first season as we calibrate the system to the needs of our changing crops.
Three weeks after planting we began harvesting basil, spinach, swiss chard and other greens. A sign posted near the roof entrance tells residents which crops are ready to harvest. Gardeners also shared one-on-one harvesting tips with their neighbors.
Less than a month after planting the members of Umbrella House were enjoying fresh produce from our rooftop garden.