Roof Gardens: The Cool Solution to Summer Heat
Updated: Feb 21
The summer swelter is coming very soon and inner city temperatures show no signs of decreasing. No matter how many iced teas we drink or pools we jump into, it seems nothing will save us from the oppressive heat. There is an explanation for these harsh heat waves that bake us on the asphalt and, thankfully, a solution!
Standard tar and shingle roofs, whether flat or pitched, get pounded by sunlight all day, and since the darker materials absorb so much of the radiant heat, they can become hotter than the surrounding air—bless our roofing crews, wherever they are. Tightly packed urban sprawls and metropolitan areas have a measured increase in temperature causing a “heat island” to form. This isn’t an island you want to brag to your friends about vacationing at though; it has more negative impacts on your daily life than that sunburn and margarita hangover. According to the EPA, the annual average air temperature can be 1-3°F warmer than surrounding suburban or rural areas and with so much sunlight absorption throughout the day, and no relief comes in the evening either. Evening temperatures can be 22°F than early afternoon temperatures which means more post-dinner ice cream to cool off, but also higher air conditioning costs, air pollution, energy consumption, and heat-related deaths. That is not a fair trade-off, no matter how delicious a Dreamsicle is.
Stay cool and rejoice Greenscape Geeks has a beautiful story to tell about rooftop gardens! Rooftop gardens are not new, although their construction has caught on in recent years in large urban landscaping centers. Roof gardens are most popular in cities such as New York City, Miami, and Chicago to name a few. These elevated oases can help disperse the heat that gets trapped by traditional roofs by using the sunbeams to grow plants (or food). Native plants and drought-resistant plants will also help reduce stormwater runoff, improve air quality, and create a habitat that birds and local pollinators can enjoy. You will have a pollinator party every day at no extra cost; what a gracious host you are! This is a ton of added environmental value to having an eco-friendly landscape on your house, but planning a garden like this will take serious planning and additional know-how besides regular watering and weeding.
Photos clockwise from top left: A scenic view along the New York High Line Park--photo credit Greenscape Geeks, maximum relaxation with pots and hammock--image © Roof Maker, Clean lines and plenty of room to walk--image © Port and Quarter, mix and match--image © Bob Vila, a wild meadow on a walk-up--image © 1001 Gardens
Whether you envision a hodge-podge of potted plants or a carpeted grass approach for a top-floor meadow, you should check your local gardening laws and building ordinances for the green thumbs up on your project. If you intend to cover the entire roof area in plants, consider the weight of the soil you will use and account for the added “wet” weight of it when it is soaked. Acquiring architect and contractor services, in the beginning, can help you see to the end of your project to avoid a leaky roof or worse.
If you want to create a more sectional, zen-like garden, avoid excess waste and weight by using recycled plastic pavers and reclaimed wood planters. In addition to breaking up heavy gusts of wind, raised beds or planters can be moved around furniture as needed to get your feng shui on point. It will take some creativity to make sure the planted zones also drains appropriately and are accessible to water. A rope and bucket may seem like a great way to incorporate some exercise into your daily water routine, but leave the 18th-century methods where they belong; you are living large in 2019! A water storage system is very practical and can be made to swivel or move as you need to water your plants. An automatic watering system on top of your house can make use of solar power for maximum efficiency. We know Indiana’s own Rectify Solar company can give you the information you need to help your roof garden shine brightly! Not only do they have excellent customer service to keep you plugged in, but they also offer tax credits for solar panel installations.
Take a page from Andrew Henry and think about starting a roof garden build on your own. With thorough research and planning, your design can cut down on sweat from mistakes as well as from the furnace outside your door. You’ll appreciate the hot savings, both financial and environmental, and have an incredible green escape for when the freezer is empty, and the multiple box fans offer no relief.
Roof Garden sources:
Greenscape Geeks, LLC
https://www.epa.gov/heat-islands - Environmental Protection Agency
https://tinyurl.com/y5rkjlyk - Gardening Know-How