My experience is that gardeners tend to underestimate rainfall. Although a cloudburst may seem to have saturated the ground completely, if you scratch down an inch, you might find dry soil.
It is important to pay more attention to the cloudburst as it can affect your garden’s ability to water properly.
In inches, we often refer to the amount of rainfall that fell, how long it took to water your plants or how much water they need. Plants need approximately 1 inch of water each week to thrive. You can easily measure it with a rain gauge. This can be bought or made at home using a cup of coffee or another can and a ruler.
My neighbor calls me every morning, after a night of rain, to ask “How many inches have we gotten?”
The rain gauge will tell you how long it takes to water your garden. You can distribute the water unevenly by placing a few cans around the area you want to water. Turn on the spigot and continue to turn it on until the sprinklers fill the cans with water.
It takes approximately 27,000 gallons to cover 1 inch of an acre with water. An inch of water equals 90 gallons in a 150-square-foot garden.
Use the 1-inch measurement to determine how much water you need for each plant when watering with a bucket, watering can, or other watering device. It is particularly important to water shrubs and trees that have just been planted.
First, determine the area where the roots will spread. This can be done in a bird’s eye view. This is usually the same as the horizontal spread. For example, the roots of a rose bush that I planted last spring probably have spread out over several square feet. Two square feet (or 288 square inches) times 1 inch of depth equals 288 cubic inches, or approximately 5 quarts, water.
You could also translate the rule as follows: Every week, add 2 1/2 quarts water per square foot. It is simple to determine how much water you use by using a watering container. You can calculate the output of a hose over time and then determine how long it takes to provide enough water to your area. You might be surprised at how long it takes to get enough water for the area you are watering.
This guideline is applicable to soil that hasn’t dried out too much. You must first get the soil thoroughly soaked in water if it is dry from not being watered for 3 weeks or more. Next, water the soil for an inch or 2 1/2 quarts/square foot in one week.
This “inch” rule also applies to plants with roots that are mostly in the soil’s upper foot, which includes most annual and perennial vegetable and flower plant species. More water is needed for plants that have roots deeper than one foot. Corn roots, for instance, are 3 feet deep.