As important as fertilizing your garden is, nothing is more important for your plants than making sure they get the proper amount of water.
If we use the food analogy, you can survive a lot longer without food than you can without water. The same can be said about your plant. It will get at least some nutrients from the soil around its roots. But without water, the plant will shrivel up and die. Too much water and it will drown (or rot).
Many factors affect how often you must water your plants. Some of these factors are heat, humidity, wind, season, soil, and type of plant.
Water enough so that the soil becomes wet throughout the entire root area. This will require a slow, soaking irrigation. Water should be applied only as quickly as it can be absorbed by the soil. Keep in mind your deepest roots will be located below the trunk and limbs of the plant. This area will require more water than the shallower roots located near the end of your farthest watering area. Root depths are commonly 6 to 12 inches for annuals, vegetables, and lawns—12 to 24 inches for perennials and shrubs—and 28 to 36 inches or more for trees.
Once a plant has become established most recommendations suggest it needs at least 1 inch of rain (or watering equivalent) every week during your growing season. Fast growing plants will require more water than slower growing plants.
Keep in mind that the soil type will greatly affect how often you will need to water your plants. Sandy soils do not hold much water, so when you irrigate or when it rains, most of the water percolates rapidly down and out of the root zone. Plants grown in sandy soils will need to be watered more frequently. On the other hand clay based soils hold more moisture which remains available to the plant for longer periods of time. Plants growing in clay soils require less watering.
Hot, dry, or windy weather increase the need for extra irrigation. Pay attention to your entire garden and water as necessary. It is best to water during the early morning or late evening, but if a plant needs water, water it regardless of the time of day.
Since summer offers some of the hottest days, depending on how much sun your garden gets, it is possible some or all of your plants may need to be watered every day.
If you are unsure that your plants are getting the proper amount of water, try the scratch method to help judge the situation. Using a hand trowel or other implement, scratch below the surface of the soil and check the soil in the root zone for moisture. Moist soil tends to hold together when squeezed, dry soil typically will fall apart. If you judge the soil is too wet—stop watering for a while and let the plant dry out. If you judge the soil is too dry, water it as outlined above.
As a general rule, container plants typically need more watering than those in the ground. But be careful to make sure the pots, baskets, boxes or containers have proper drainage or the plants will drown. As always, your planting guides are going to do a much better job of instructing you on how much water your different plants need than we can do in one article. Plus they often offer guidance on using things like mulch or specific soil combinations that will help the plant maintain the ideal amount of moisture.
Even with a planting guide, watching your plant and the soil is important.
Signs of "Over Watering":
Too much water drowns the roots and deprives the plant of the food and moisture that the roots are supposed to supply. The first signs of too much water show up in the roots. They become brown and mushy. This is hard to see in the garden but easy to check with plants grown in containers. In the garden, symptoms of over watering are yellow leaves (generally all over the plant) which will soon drop off. Once this occurs, it is often too late to save the plant.
Signs of "Under Watering":
Too little water deprives the plant of the moisture needed to grow and live. First signs are a slightly washed out color in the leaves, followed by wilting, starting with the youngest and tenderest foliage. If wilting is severe enough, damaged leaves with brown crisp edges may remain even after watering. Very severe wilting is not reversible and plants will die.
Finally, who ever said gardening had to be boring? Keep it fun. Make gardening a family activity. Check the plants and soil moisture with the kids. Let them be involved in watering and feeding the plants. And, somehow, a garden hose always turns into more than simply watering the garden.
Watering During the Fall
  • A deep root watering is needed prior to the first freeze. Gradually reduce the watering for your plants from a daily watering to weekly watering to monthly throughout fall and winter.
  • Allow the water to extend beyond the drip line of trees and large shrubs. A thirsty plant going into the cold season will be much more susceptible to winter damage than a well-watered one
  • If you made a basin around the base of the plant/shrub to hold water during spring and summer months, make a hole in it so water can drain away and not freeze the plant.
  • Monitor weather conditions and water during extended dry periods without snow cover - one to two times per month.