Graze the Roof: The Glide Foundation Rooftop Garden Project

Image by Jessica Kraft

Bay Localize is proud to share this web page as an overview of Graze the Roof, an edible rooftop garden project at Glide Foundation. The following will tell the story of how this project was initiated and includes a description of the roof garden program and the technologies demonstrated.

How the Project Started

In May of 2008, Cliff Mojo Bar and Focus the Nation awarded Bay Localize '07-'08 intern, Maya Donelson, the Slingshot Grant, a national grants program that empowers young people to accelerate the transition to a just and prosperous clean energy future.

Overview

Lack of access to healthy food is one of the great, yet often unspoken forms of oppression. Graze the Roof engages inner city youth and adults in sustainable, low cost rooftop food production from seed through harvest and works to eliminate inequalities and greenhouse gas emissions in our food system by encouraging people to become more self-sufficient and make healthier food choices for themselves and for the planet. For further details on the project, please see below.

Graze the Roof Workdays, Workshops, and Tours: Community Work Days: Every Thursday and First Saturday of the Month 10:00AM – 1:00PM – Thursdays 10:00AM – 1:00PM – First Saturday of the Month RSVP in advance to Glide's Volunteer Coordinator, Shannon Brady at sbrady@glide.org Workshops: 2nd Saturdays of the Month 11:00AM – 1:00PM Cost: $5 donation (no one turned away for lack of funds) RSVP in advance to GrazeTheRoof@gmail.com. Tours: 1st Sundays of the Month 10:30AM and 12:30PM We will meet in Freedom Hall after each morning service. No RSVP required.

Project Summary

Over the course of the summer, Graze the Roof was supported by a host of
volunteers, Bay Localize, Glide Foundation staff, and commercial businesses who came together to construct and install the garden in a mere three months. The work of these volunteers proved instrumental in the design, construction, and success of Glide's Rooftop Garden. These volunteers and community members were able to learn about appropriate materials and systems for rooftop agriculture while gaining practical, hands-on experience that can be applied to individual projects.

The project and garden components are complemented by fourteen beautifully designed and inspiring educational murals designed by Jessica Kraft of Six Degrees of Sustainability which depict the story of local food production: from seed to harvest.

Over the summer the garden also became part of Glide's Janice Mirikitani Family, Youth, and Childcare Center (FYCC). Children got their hands dirty and learned about plant propagation, germination, transplanting, composting, vermicomposting, healthy soil integrated pest-management, harvesting and the importance of local healthy food. The engagement of local children with the garden is an essential component of Graze the Roof's future goals which are listed below.

Project Goals:

Research and Development:
Developing and demonstrating sustainable, low cost, lightweight, productive, space conserving rooftop garden solutions that can be easily replicated.

Environmental Education:
Introducing inner city youth and adults to a natural environment where they can learn about the importance of rural and urban food production through hands-on experience.

Food Security:
Growing organic healthy produce for inner-city youth and adults.

Climate Change Mitigation:
Conserving energy in the buildings and reducing greenhouse gas emission in our food system.

Rooftop Technologies and Systems:
Graze The Roof utilizes a variety of components that provide cost-effective and energy efficient solutions to create a productive rooftop garden. The project includes growth mediums as well as compost tumblers and vermicompost bins to create an integrated food system that consumes waste and produces vegetables.

The Compost Tumbler

This custom built compost tumbler creates high quality compost in a faster, cleaner and easier process than conventional composting. This garden generated compost reduces the volume of waste that would otherwise be sent to landfills and instead creates valuable soil amendment to replenish nutrients and organic matter.

The compost tumbler system is comprised of two 55-gallon drums on the rooftop. One 55-gallon drum is used to hold the appropriate compost mix while the other barrel sits on its side on a track of wheels that roll the barrel to generate a fast rate of "baking" and composting. This process is called batch composting and is a "get-rich-quick" type of composting. Once the first batch is finished, the next one is ready to go. Frequent rotation of the compost tumbler breaks the material down faster to create a final product of soil in a turn-over rate of around 30 days.

The drums are pierced with holes for air vents and sit and rotate on four rigid steel casters for easy mixing and aeration. The drums are designed with a twist off lid so organic material can be loaded and unloaded with ease.

Vermicompost Bins

Vermicomposting uses earthworms to turn organic wastes into high quality compost. Graze the Roof has two vermicompost/worm bins that produce organic fertilizer for the plants. The design is wide and shallow to give the red wrigglers enough room to feed. A thin layer of newspaper is placed on top of wire mesh that lines the bottom of the bins. Atop the newspaper lies a thin layer of compost for bedding. The worms are placed on their bedding and food waste is added on top, which is covered with shredded newspaper to prevent fruit flies and other creatures from having access to the food scraps.

Worm castings are ready for harvesting after a three to six month period of cultivation. The worm castings fall through the wire mesh to the bottom of the worm bin where they can be scooped out, separated, and used as fertilizer. The castings can be used in their solid state, by sprinkling them around the base of the plants or they can be integrated directly into your garden beds soil mix. Worm castings can also be used to brew a nutrient rich worm tea.

Worm Tea Brewing Station

Worm Tea is a rich organic fertilizer, made by steeping and aerating worm castings in water to release nutrients in the castings and to wake up beneficial fungi and bacteria that otherwise lie dormant. Worm tea is an all organic liquid fertilizer. When worm tea is sprayed on the leaves of plants it helps suppress foliar diseases and increases the amount of nutrients available to the plants.

At the Glide roof garden, the worm tea brewing station is equipped with a 30 gallon plastic bucket that sits beneath a small shade structure. The tea is aerated using an air stone and an aquarium air pump. If the tea is not aerated constantly, the organisms in it will quickly use up the oxygen and the tea will become anaerobic. Anaerobic teas can harm your plants.

Miniature Greenhouse for Plant Propagation

A miniature greenhouse helps protect seedlings during their first growth phase. Plant propagation is the process of selectively reproducing plants through the germination of seeds and the growth of seedlings.

The miniature greenhouse frame is made from recycled lumber and a recycled window frame for the door. The green?house is covered in plastic to hold in moisture and heat.

Rooftop Bread and Milk Crate Planters

Milk crates make elegant and affordable raised planter beds when dressed up in a refurbished shipping pallet frame. A milk crate, at one cubic foot, is the perfect size and depth for crops that need between 8 and 12 inches of growing space. The crates were lined with black landscape filter fabric that contains the soil and allows for aeration and drainage.

The finished planter beds also boast an element of water and nutrient conservation. They are designed to slope and drain along the center where runoff water and nutrients are captured in two gutters hanging below the bed of milk crates. The water and nutrients are then drawn back up into the planter bed through a capillary wick system.

Each milk crate container is filled with a lightweight soil mix recommended and supplied by American Soil and Stone in Richmond, CA. It is a mixture of 50% pumice (or perlite), 20% coconut coir, 15% greenwaste compost and 15% grape compost.

Hydroponic Growing Systems

Soil-less gardening/hydroponics is the method of growing plants by sup?plying all the necessary nutrients to the plants through water as opposed to soil. The rooftop features the Power Grower 8-pack system by General Hydroponics and is an experiment in soil-less gardening technology.

Hydroponics have the advantages of being prolific, water conserving, lightweight, and space conserving; however, the system requires certain chemical inputs that compromise the sustainability of the overall integrated system.

Graze the Roof hopes to move to an organoponic system that will utilize organic inputs to achieve a sustainable balance for the garden. If you have knowledge of these growing systems, please feel free to share your information and expertise with the gardeners at Glide!

EarthBox Planters

The Glide roof garden is successfully growing a variety of veggies with the Earth Box system. EarthBox is a commercially available self-watering container with an irrigation reservoir built in as a bottom tray to supply water to plants for multiple days. The EarthBox reduces the water requirements for vegetable cultivation by eliminating evaporation and run-off. The reservoir provides a constant supply of water to the plant as long as it is kept full of water. Plants draw water from the EarthBox reservoir only as needed, thus reducing the need for manual irrigation.

For more information and to make a donation to help steward the Rooftop Garden into 2009, please visit http://glide.org/GrazetheRoof.aspx

You can also contact Maya at maya.donelson [at] gmail [dot] com