Effective watering is good all around: good for the garden, good for the environment, and good for your wallet. I have to make a confession here. I had another Technique article planned for this month, but the watering practices of one of my neighbors, and the toll it is taking on my sanity, prompted me to write this. So bear with me if I go on a rant here or there!
Annuals and Perennials
Annuals should be watered deeply and infrequently. They need about one inch of water per week. It is best to deep soak them once a week, rather than giving them a sprinkle of water every day. If you water that way, the roots won't go down into the soil to find moisture, since you're providing it all at the surface. Plants with shallow roots are more susceptible to heat and drought.
Perennials are easy! After a perennial is established, after its first season in your garden, it will need no supplemental water. For that first season, water perennials as you would water your annuals to encourage deep root systems.
While a shrub is getting established, for its first year in your garden, it will need one inch of water per week. It is best to give them a nice deep soak, as described above. After that, they don't need any supplemental watering.
This is the one that kills me. If cared for properly, lawns are actually fairly low maintenance, and, believe it or not, watering is probably the biggest path to success or failure. I discussed how you don't want to just sprinkle annuals all the time, because their roots won't stretch deep into the soil. I see people do it to lawns all the time, and it sure seems like it's working for them, because those people usually have the nicest, greenest lawns on the block. My neighbor, who I mentioned above, goes out every day and uses her hose to give her lawn a sprinkle. When I say every day, I mean every day, including the day after a soaking rain, and, even worse, during a soaking rain (no, I am not kidding. The woman was literally standing on her lawn with an umbrella in one hand and her hose in another. Please, in the name of all that is good and holy, don't do this. Please.) And, I'll admit that even though I know better, her method looks tempting, because she's got the greenest grass. But, were this neighbor to decide to go on vacation for a week, she would return to a very brown lawn, if not a dying lawn. Because she waters just a little tiny bit every day, the roots of her lawn are super shallow. Her lawn depends on that daily watering, and, since it has no need to stretch its roots, it puts its energy instead into giving her nice green blades of grass. You can have a beautiful green lawn, and, more importantly, a healthy green lawn, if you water it correctly. Lawns, like annuals, need one inch of water per week. Give the lawn a deep, thorough soaking once a week, and its roots will dig deep into the ground. A strong root system makes for a strong lawn, and in a short time, you will be rewarded with that green carpet we all desire. Even more importantly, should you decide to go on vacation, or should we go through a drought, as we sometimes do, your lawn will be just fine.
One inch of water once a week, if you don't get it by a nice rainstorm. How easy is that? You will be rewarded with a healthy green lawn, more money in your wallet, and, maybe best of all, more time on your hands. ITGO