Here is a brief description of my raised planters:
I have 9 self watering planting beds that are each 75cm W X 110 cm L X 20 CM D) The planting beds are composed of 5 parts:
1: The concrete and CMU block structure of the raised beds (so I do not have to bend over). The interior of the planting chamber is lined with a waterproof membrane.
2: The perforated supporting deck under the planting medium is corrugated fiberglass. The holes are drilled at 15 CM OC in the trough of the corrugation.
3: The planting medium is 4 equal parts of organic compost, pro-mix, peat moss and vermiculite. This means no compacting, no nematodes, etc. On top of the corrugated supporting bed is 5 CM of pure peat moss that wicks water to the planting medium. The planting medium is 20 CM deep.
4: The continuous water supply is controlled by a vertical float value (bought from the UK) that is set to keep the water at the 1/2 point of the corrugated fiberglass support deck (#2 above)–this provides a constant supply of water to the peat moss layer that then wicks the water, on demand, to the plants above. The beds are compartmentalized so that I can segregate plants by type, whether they need shade, etc.–since some plants draw more moisture than others. Here in the Yucatan, it is a) not advisable to water from above and b) not to use “soil” -it hardens and cakes.
5: an overflow pipe that keeps the water level during rain events. When we are in the rainy season, we can get an inch+ of water in a down pour. This system makes sure the planting medium is moist not soggy.
Please note this is NOT my invention. It was developed by Robert Kimsey here in Merida and is also inspired by Mel Bartholomew’s “All New Square Foot Gardening” system (see Square Foot Gardening Foundation.) I used his book and Lucy Halsall’s “Small Plot Big Harvest” book for advice on spacing, plants, etc.
I am having a vertical support system made over the next few weeks. This will allow me to customize the shading and the vegetable support netting for beans, tomatoes and melons.
Going to Chicago Monday, but looking forward to seeing the progress in a few weeks! Pam and I are going to try it ourselves in the next few months.
let us know when you get back