Watering Tips
Watering can be very difficult to understand. It seems that there is always too much or too little. What is the right amount? Water is sometimes called a "hazardous necessity". You can certainly kill a plant with too much water. Roots need air to breathe. Depending on the plant it is only a matter of time before they will drown.
1. Water deeply and Infrequently. The idea is to deliver water to the deepest roots. This can be as much as 6 to 18 inches in the garden. When watering a container use enough water so that it drains out of the bottom of container. A good rich soil full of organic matter will retain water much longer than plain sand or clay. An inch of water will penetrate about 12 inches in sandy soil and only 4 inches in clay in a 24 hour period. In the garden there is a time when you need to water more frequently and that is when plants are very young and their roots are very shallow.
2. Watch Out for "Water Stress". This is a term which is beginning to be used as a way to describe a plant that is not getting sufficient amounts of water to reach its potential. This stress can be slight to severe as the soil moisture decreases and the plant must work much harder to survive. This causes the plant to be more susceptible to all kinds of insects and disease. All vegetables show different effects from water stress. Tomatoes will ripen their fruit all at once. Melons will lose sweetness. Cucumbers will stop growing. Vegetables will never fully recover from a severe check in growth due to lack of water. Water in container gardens is much more critical due to the smaller space for roots. Some large plants may require more than one watering a day.
3. Water Sources. We all get our water for our plants from different sources. Municipal water, well water, spring water, river, stream or lake water, rainfall, desalinated sea water and by the gallon in some hard cases. Many of us have more than one of these water sources at our disposal. Some areas rely totally on rain for their water and have to harvest and save every drop.
4. Save Money and Natural Resources by Using Rainwater for Your Garden. If you use the right resources you can keep your garden healthy year round by using only rainwater. There are a few places on earth that this will not work mostly because have little or no rain. If you live in one of these places lower your expectations as required. The best way to collect rainwater for most of us is to use the roof of our house to collect rain and funnel it into containers. In places where the rain is the only water available, houses are built with huge tanks underneath to hold thousands of gallons. Every shed, barn, garage or any structure on your property can be used for water harvesting. You can buy tanks, barrels and other containers to hold rainwater. 
5. Watering Tips and Guides. Water early in the morning when less moisture will evaporate. Watering at night encourages foliage disease. Water the soil around the plants rather than watering the foliage. This discourages fungus and mildew. Any type of wind protection in the garden will cut down on evaporation. Furrow watering is a way to use less water because it gets the water more directly to the roots and this method has been used throughout history.