The Garden of Wonder at PS 133 in Brooklyn now has five sub-irrigated planters (SIPs) of the raised bed type, including a partially planted demonstration planter. All planters are prefabricated kits from Home Depot.
The sub-irrigated raised beds are in addition to 70 tote box SIPs and 30 feet of dual-track sub-irrigated rain gutter system housing a garden of large round planters.
The benefits of all sub-irrigated planters (SIPs) over traditional top-watered beds for vegetable growing is increased productivity (up to 50%), reduced water usage (up to 90% less) and ease of use for all gardeners, novice or experienced.
They are also the safest, most hygienic, way to avoid toxic metals contaminated urban soils. The plant root system in SIPs is never exposed to the underlying soil. The same cannot be said for conventional raised beds.
Research shows that city soil contamination is widespread and under-reported by the gardening media. Lead contamination is of particular concern where there are young children involved.
Although the planter kits are relatively lightweight cedar, they will likely outlast heavier planters because they are not exposed to water. Sheet plastic liners make them watertight.
You can assemble the kits with a screwdriver, but it is much faster to use a power drill (screw driver attachment). You will also need a drill to bore a hole for the overflow drain hole. A heavy-duty stapler is the best way to fasten the liner. A rubber mallet is also helpful when assembling the planks and corner posts.
After installing the liner, the next step is to create the water/oxygen reservoir system. We used recycled nursery flats installed upside down for these beds. They are quick and easy to install and you will be helping the environment by keeping them out of landfills. Find them at your local garden centers and/or landscape contractors.
Other recycled food containers such as milk and juice bottles, produce containers (ex. mushrooms) also work well. Perforated, corrugated drain pipe (aka ag pipe) works but you may have to special order it at your local home improvement store.
Final steps are the addition of a fill pipe in one corner and one or two overflow drain holes (1/2" clear plastic tubing extending from one of the reservoirs through the wood to the exterior).
Stay tuned. There are many more photos to come showing other wonders of the PS 133 Garden of Wonder.