STEP 1 - Installation of Deck
This deck was installed using a pedestal system that helps keep the entire deck surface level, while allowing water to flow beneath them and make its way to the drain. This sort of system works really well for roof gardens, which need to be kept lightweight and clear of obstructions that can build up over time. It also enables easy access to the drain for cleaning and allows sections of the patio to be taken up for cleaning and maintenance as needed.
STEP 2 - Put weed barrier fabric in all pots
A layer of weed barrier fabric at the bottom of your pots will let the water out but keep the soil in the planter from leaching out onto the deck. Choose a thin weave weed barrier fabric, as the thicker cloths tend to not drain as well.
STEP 3 - Installation of Lighting and Irrigation Lines
We left a 1-inch gap around the entire perimeter of the deck to run all of our irrigation and lighting lines discreetly up into drainage holes drilled into the bottoms of the planters. If you've never installed irrigation or lighting lines before, check out my Instructables on how to do both of these. Drip irrigation actually ends up saving people money over the long-run on having to replace plants because it waters the plants for you automatically just the right amount. Low-voltage up-lighting can be placed into the soil around the plants using metal stakes.
STEP 4 - Mulch
A 1-2 inch layer of mulch at the top of your pots will help hide irrigation and lighting lines for a more attractive surface appearance.
Step 5 - Relax and Enjoy your New Garden!