The cost of water in our area is very high so every drop of water counts. The most efficient way of watering a garden is by using drip irrigation and black plastic. The plastic prevents the water from evaporating into the atmosphere, and the hoses water the roots of the plants and not the leaves, which helps to prevent molds, mildews and other diseases. If your garden is too large, you will have trouble establishing and maintaining a black plastic and drip hose system, which is why we like our smaller garden. For instance, it is said that most gardens need 1 of water per week for optimal growth. This seems reasonable until you do the math: a 1 acre garden would require 27,000 gallons of water for that 1 of water, and at the cost of 1 cent per gallon (which is what we pay for water) that comes to $270 to water a 1 acre garden. Our small garden is as efficient and carefree as you can get without spending a lot of money. Dont make the mistake of building too large of a garden, as the cost for water alone can make the venture economically impractical.
In the USA today we are seeing the beginning of nasty fights between farmers and environmentalists over water-rights issues, and between states that have water and those that dont. Water used to be cheap and plentiful, but today has become scarce and expensive. When you plan your garden think about how much water it will require, and dont expect nature to supply all of it free of charge. Using our technique of drip hoses covered by black plastic makes a lot of sense in these times.