How to Build a Rooftop Garden

Assess the roof's ability to hold the garden. A high-pitched roof would not be a good candidate because of the difficulty in keeping pots and raised beds secure. It can also be difficult to walk on. A flatter roof is a better prospect, but it still must have a bit of a slope to accommodate water runoff.

Check with your city or county for any required permits needed for rooftop gardens. This will vary from location to location. Some cities require that your roof be inspected before building your rooftop garden. The inspector or a building contractor can tell you how much weight per square foot your roof will hold. You must comply with the weight assessment.

Consider the water source. Will you need to carry containers of water up to the roof, or is there access to a water spout to which you can attach a hose? The availability of a convenient water source may determine how large you will build your garden.

Decide what you will grow and the size of containers required. You may want to start with a small variation of pots and raised beds. Make sure all the containers have adequate drainage holes and that the water can drain easily out of the bottom of the containers. This could mean attaching additional thin strips of wood to each side of the bottom of the raised beds so they are lifted off of the roof slightly.

Bring all of your gardening supplies up to the roof separately. It will be easier to plant seeds and plants in containers after you are on the roof rather than trying to carry them up after planting. Container rooftop gardens can be started with just a few pots, adding a few new ones each year.

Place your plant containers so they will receive the most amount of sunshine throughout the day. This means being mindful of trees and buildings that may cast shade upon your garden.