One of the reasons schools and individuals have trouble maintaining their gardens is that they put the garden in, water the plants and then assume the plants will thrive on their own. Unfortunately, that doesn’t work and the plants wither.
In general, I either recommend a Timer system for schools or a dedicated volunteer who will water on a regular basis. Depending on rain, I’d recommend at least once or twice a week to keep plants happy that first year. The problem with volunteers is that they come and go and at some point the garden is on it’s own. This is a good reason to use natives, but still watering the first season is critical.
Jesse Gilbertson, Horticulture Director for U City in Bloom, doesn’t put in any new garden without a water source. Find money to get irrigation – at least a spigot. They do have a water “truck” to water containers.
Scott Woodury of Shaw Nature Reserve says, “Establishment watering is critical for any planting. The establishment period might be three months long, it might be the entire growing season….let’s call it the first growing season.
I personally use a timer on my hose with a sprinkler. It’s an inexpensive solution and only puts down the amount of water which is needed.