Obviously, water requirements vary from plant to plant. If you’ve matched plants to the environment in your garden, incorporated plenty of organic matter into your soil, and provided your plants with a moisture-retaining layer of mulch, your plants may do fine with the water naturally available from rainfall. You’ll need to water new transplants until they become established and if weekly rainfall is inadequate.
Soil type - Of course, the amount of watering you need to do will also depend on your soil type. If you have sandy soil that is unable to hold much water in reserve for plants, you’ll need to water more often than if you have loamy or clayey soil that can hold plenty of moisture.
Wilting - A plant reacts very simply to too little or too much water – it wilts. Wilting that occurs during the heat of a midsummer day is common and temporary; don’t be alarmed by it. However, wilting that extends beyond the heat of the day, especially if it occurs in the morning, is a signal that the plant is suffering a serious water shortage.
One Inch A Week - Keeping track of rainfall helps you avoid over-watering or under watering your flower garden. The best way to do that is to mount a rain gauge someplace in or around your property. Remember to empty the gauge after each rainfall. Keep track of the rainfall on a weekly basis. If, after a few days, less than ½ inch of rain has fallen, you should think about watering, particularly the annuals or new transplants. You don’t have to keep precise records on paper. Just keeping rough track in your head is all that is needed to use this easy system.
Watering Equipment - There is the whole range of watering equipment options located in the Watering Equipment files in Yardener’s Tool Shed. In flower beds we use porous soaker hoses.