Creating a Sustainable Rooftop Garden

Thinking about going green in an urban environment? The challenge is worth the reward.

As the United States focuses more on sustainability, many businesses and homeowners are choosing to “go green” – implementing simple initiatives like composting, using canvas bags and recyclable materials to minimize long-term environmental impacts. Many cities like Chicago even offer tax breaks for making a property more eco-friendly and because of this, rooftop gardens have started to become a staple in many neighborhoods.

The city is one of the leaders in this development – with museums, corporate headquarters, hotels, City Hall, and a number of local companies dedicating their efforts to making Chicago a greener place, including full-service urban landscaping company Rooftopia.

The rooftop garden, roof deck and landscape business was co-founded by Jenn Lassa and Marcin Matlakowski in 2009 on the principal that urban life doesn’t have to be a concrete jungle – there are ways to create a more sustainable, beautiful future by filling empty space with vegetation. Some of their more notable projects include cozy terraces scattered across the Lincoln Park and Wrigleyville, minimalist garden designs inspired by the Museum of Modern Art in New York, and garages turned into oases for homeowners.

“When my husband and I started the business together, our ultimate goal was to provide more green space in the city for outdoor entertaining and enjoyment,” said co-founder Jenn Lassa. “Most people in Chicago have either no yard or a very small backyard. The roof was the most practical place to build our gardens and enhance any existing outdoor space.”

Sustainable rooftops offer a number of benefits like regulating the temperature of a building during the summer and winter months, producing oxygen, purifying air, and reducing stormwater runoff to help prevent flooding. But these designs are more intricate than boxed planters and seeds.

“For anyone who is considering a rooftop garden, the best first step is to look at the structural design of your building. Code requires your roof to be able to hold a minimum of 100 pounds per square foot,” according to Lassa. “This isn’t an issue in most of the newer buildings that we service but older construction buildings often don’t meet the requirements.”

Aside from construction, it’s also important to understand the types of plants that thrive best in this unique environment. Sun exposure traditionally increases on a rooftop but in an urban environment, tall buildings can shade plants. There is also more wind compared to traditional in-ground gardening. And in cities with harsher winter weather, delicate flowers may not make it to the next season. The foliage chosen needs to be able to survive tough conditions.

“There are a lot of factors that play into the plants we chose for our gardens, but our goal is to use plants that are relatively low-maintenance,” said Lassa. “Those that can thrive without much water (drought tolerant) are usually most successful. Some examples are perennials like sedums and alliums which can often survive on rainfall alone, succulents, and plants with shallow roots. However, these all come with the sidebar that homeowners need to understand how much water these plants need to look their best because all plants require some kind of attention.”

Many rooftop gardens also require the installation of a unique drip irrigation system which helps water get directly to the roots, reducing the risk of wind preventing water from getting to the source and lessening maintenance requirements for the homeowner. Ultimately, these steps are meant to improve longevity, ease, and enhance the beauty of this extraordinary type of garden.

“It’s really rewarding to transform a space that is completely unusable into a space that people gravitate towards,” said Lassa. “It can be challenging to get to the roof but once progress is being made, the final results are incredibly rewarding.”