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- Water waste through evaporation.<\/li>\r\n
- Weed growth.<\/li>\r\n
- Overspray onto plant leaves and foliar diseases.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Designing and building an automatic watering system is a complex task. You probably want to enlist the services of a professional or of a knowledgeable volunteer. However, there are resources and products available for those who elect to do it themselves. The essential parts of an automatic system include a shutoff valve, a pressure regulator, a filter, a timer, pipes or tubing and emitters.<\/p>\r\n\r\n\r\n\r\n
Collecting and Using Rainwater<\/h4>\r\n\r\n\r\n\r\n
You may have the opportunity to collect and use stored rainwater. Check with your district on their policy. Rainwater harvesting can be a value-added method of irrigating crops in a school garden, but you must be sure to divert the first rains away from the storage tank. First rains wash off substances that have been baked onto the roof and\/or rain gutters during many months of hot San Diego sun. They may include toxic roofing sealants, smog emission residues, bird and rodent feces, decomposing insects, weed seeds, leaves and more.\u00a0 If these toxins enter the tank, they will contaminate the water and make it unusable to irrigate edibles.\u00a0 First rain diverters are common add-ons to rain harvesting systems, but if your school does not have a diverter, you may use harvested rain water only to irrigate ornamentals, shrubs and trees.<\/p>\r\n\r\n\r\n\r\n
\r\n![\"\"](\"http:\/\/mastergardenerssandiego.org\/schools\/plant-a-seed\/wp-content\/uploads\/2019\/02\/GoogleDrive_rain-barrel.jpg\")
<\/figure>\r\n<\/div>\r\n\r\n\r\n\r\nOllas and Wicking Beds<\/h4>\r\n\r\n\r\n\r\n
Ollas were introduced to the Americas by\u00a0Spanish\u00a0settlers in\u00a0colonial\u00a0times. They are unglazed, porous, glazed containers shaped like a jug with a narrow neck and lid. The\u00a0olla\u00a0is buried in the ground next to the roots of the plant, with the neck of the\u00a0olla\u00a0extending above the soil. The\u00a0olla\u00a0is filled with water which gradually seeps into the soil. It is an efficient method, since little water is lost to evaporation or run-off. The ollas are fitted with caps that reduce evaporation.<\/p>\r\n\r\n\r\n\r\n
![\"\"](\"http:\/\/mastergardenerssandiego.org\/schools\/plant-a-seed\/wp-content\/uploads\/2019\/02\/GoogleDrive_Olla.png\")
<\/figure>\r\n![\"\"](\"http:\/\/mastergardenerssandiego.org\/schools\/plant-a-seed\/wp-content\/uploads\/2019\/02\/GoogleDrive_Olla-2.png\")
<\/figure>\r\n\r\n\r\n\r\n<\/p>\r\n
Wicking beds\u00a0are raised garden beds with a water reservoir underneath. They can be made from a variety of watertight materials. Water is automatically wicked upward to water plants from below rather than from above. They are basically containers with water reservoirs at the base – like a giant self-watering pot. Moisture is drawn up through the soil via a process called capillary action or\u00a0wicking.<\/p>\r\n\r\n\r\n\r\n
\r\n![\"\"](\"http:\/\/mastergardenerssandiego.org\/schools\/plant-a-seed\/wp-content\/uploads\/2019\/02\/GoogleDrive_Wicking.jpeg\")
<\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n\r\n![\"\"](\"http:\/\/mastergardenerssandiego.org\/schools\/plant-a-seed\/wp-content\/uploads\/2019\/02\/GoogleDrive_Wicking-BEd.png\")
<\/figure>\r\n<\/div>\r\n\r\n\r\n\r\nFor more examples of Irrigation techniques, see Drip Irrigation Self Watering Planters in the Presentation section of our website.<\/p>\r\n\r\n\r\n