Click on the photo to see a Flickr album of how-to and archival photos monitoring progress of the garden. Or, click here.
This is a relatively small water conservation garden here in San Diego. It is a precursor to a much larger community production and applied research garden. I am currently looking for a neighborhood location in the City of San Diego.
Significant benefits of SIP gardens over traditional drench and drain gardens are:
* Water savings in the range of 70-80
* No runoff of water and nutrients
* Increased producivity of edible plants
* Ease of use for all ages from childhood to old age
* Sustainability - no more short life plants due to uneven watering
All of the planters in this test garden are equipped with simple, inexpensive DIY sub-irrigation plumbing made with readily available materials. Objectives are simplicity and affordability for the mainstream market of citizens of all ages who are not gardeners per se. There is no need for a mythical green thumb when growing plants in sub-irrigated planters (SIPs).
This bubble SIP design is an insert for any watertight container. The reservoirs are made from a wide variety of recycled food containers. Most of the bubble reservoirs in this test garden were made from round 48 oz Glad type food containers. The fill tubes are recycled water bottles. Cut the bottoms off and they sleeve together to make fill tubes for containers of varying depths. The overflow drain valves are made from readily available vinyl tubing.
The tools are simple but caution is advised when using a wood burning pen or box cutter. I prefer them to power tools. The wood-burning pen works well in making both the small holes (approx 1/8”) and the hole for the overflow drain valve. Push the pen tip through to the heated barrel and it will make a ½” hole for the tubing.
Look at the Flickr album to see a way to make a bubble SIP without drilling holes in clay or high-fired ceramic pots. Drilling holes in these pots is extremely difficult. The design uses the bottom drain hole for the overflow valve. See how-to photos - start here.
All of the plastic and resin planters (without drain holes) shown are widely available at modest prices from stores like Home Depot, Lowe’s and Rite-Aid. They are readily adaptable to sub-irrigation using the “bubble SIP” design. The bubble metaphor reflects on the need for an online supply of both water and oxygen…just like a bubble.
Plants benefit by the fact that their root system resides right over an immediate supply of water and oxygen with no need for an electric pump. The principle of ebb and flow is modeled after systems used in modern greenhouse production. As the water rises by capillary action and used by the plant, additional air flows into the reservoir. There is always a balance of both water and air in the reservoir. Sub-irrigation like this is, in fact, a simple form of hydroponics.
This garden style would work well on a patio, deck, or balcony. An ideal environment would be on permeable paving of some type. A bricks in sand patio works well. I have built several of them.
When located on a balcony there is no threat of annoying the neighbor below or causing water damage. It is sad to observe how many balconies are junk collectors or barren. I have seen thousands of them both in New York and Southern California. What a waste when they could be both productive and natural environments for residents.
SIPs are a perfect solution but we have little or no educational leadership about them at this time. That will change.