How often and how much you water depends upon how long ago you planted, what kind of soil you have, the season, the type of plant, and how much rain you have been getting.
When a plant is first planted, you want to water well, just after planting, and daily for the next few days. Then you can water more like every 3-5 days. With sandy soil, we find watering really needs to be more frequent, every 2-3 days. Clay soil retains the water more, so you may find you need to water a little less often than the above guidelines.
Weather also plays a role in how often to water. In cooler weather, one can get away with less frequent watering, but in the heat of summer the water evaporates more quickly, and you must water more often. In hotter regions, you may need to water daily.
Many times we are tempted to think “Oh good, it rained, now I don’t have to water!”. This is not necessarily true. It is very important how much rain you’ve gotten. One inch of rain may relieve your work for 1-2 days, and 2 inches may give you a break for 3-4 days. Just be sure to remember your soil type and the temperature outside will still play into the equation.
We also go by checking how dry the soil is, and keeping an eye on our plants. With relative sandy soil, we dig in the soil with our heel to find out how far down the moisture is, and know whether we need to water. A general rule of thumb for checking soil is: if you dig down six inches and can form a ball from a small handful of soil, then you still don’t need to water.
Keep an eye on how upright and healthy your plants are looking, too. Check on your plants each morning. If they look wilted, they need water. Checking them in the morning lets you know the wilting is from need for water, not from the heat of the day.
Always remember that consistent watering is a big key to the most prolific, healthy, and delicious harvest from your garden!