Conventional wisdom in the landscaping profession is that when the weather changes, you should adjust the amount of time that you water your plants, putting down more water when the weather is hot, dry, or windy, and less water when it’s cool, damp, or rainy. Nothing could be more wrongheaded. Here’s why:

First, watch this one and a half-minute video, then come back and I’ll explain why the information in the video, and all similar information that is commonly available, is foolish and dangerous. Here’s the link for the video: http://www.youtube.com/watch?v=VZyPqn7J2hs.

OK, that seems helpful, right? Well, it’s not only not helpful, it’s downright reckless. The water budget feature adjusts the watering time by a percentage, up in hot weather and down in cool weather. It sounds perfectly logical. But…by adjusting the watering time, the depth of watering changes, so that sometimes the water will go twice as deep as usual and other times it might only go half as deep as usual. The roots, and therefore the plants, don’t get what they need. And because the system won’t come on until the next regularly scheduled watering day, which is NOT changed by the water budget feature, the plants have to endure perhaps DAYS of parching weather when they really need a drink this very minute. Water is wasted and the landscape suffers. This is really stupid, don’t you think?

So what SHOULD you be changing to account for the difference in demand caused by variations in the weather? You should be changing the FREQUENCY of irrigations, going from, for instance, two days a week in normal weather to three days a week in hot weather or one day a week in cool weather. After all, isn’t that what you would do if you were watering by hand? You would say to yourself, “Oh, it’s hot and things have dried out more quickly than usual. I’d better get out there and water!” You wouldn’t wait until your “regular” watering day and then apply twice as much water as usual. So if you know better, instinctually, then how come the people who make irrigation controllers, the people who install them, and the people who teach other people how to use them, don’t get it? Beats me. It’s just one of those things that seemed like a bright idea to some engineer who didn’t know squat about horticulture, and nobody – nobody – has ever bothered to question it. And we’re talking about tens of thousands of knowledgeable professionals here. By the way, there may be a controller out there that allows you to easily change the frequency of watering, but I haven’t found it yet.

OK, so now you’re smarter than virtually every landscape professional on the planet. What are you going to do about it? That’s right. You’re going to trot out to the garage and stick a piece of duct tape over that “Water Budget” button on your timer and never, ever change it from 100%. It is set at 100% isn’t it?

Next, you’ll need a way to vary the frequency of watering. This is where things get a little sticky, because you’ll have to go into each program on your controller and add or remove days. For instance, suppose your lawns on Program One are set to water two times a week during “normal” weather. If the weather heats up, then add another day, going from, say, Monday and Friday to Monday, Wednesday, and Friday. And when the weather cools down? You guessed it: Cut it back to once a week. That’s not hard to do, but it’s a good idea to plan it out in advance to be sure you don’t create overlaps that would cause two valves to come on at the same time, overtaxing the ability of the water supply to operate the system at adequate pressure. That’s no big deal either; just be sure each program has enough open time during the week to do what it needs to do.

Next you have to keep an eye on things to be sure your new settings are actually delivering the water at the point when the plants actually need it. If you see signs of drought or oversaturation, tweak your schedule as needed. It’s really not that hard, just a matter of observing your garden as any good gardener will do. You see, those controllers aren’t very useful without the wisdom and watchful eye of the gardener to make them do the right thing. Automating the system is not the same as optimizing the system. The former is handled very well by the controller; the latter is up to you.

The rewards for better water management are lower water bills, more money in your pocket, healthier plants, and lower negative impacts on the environment. A little effort pays you back generously. Give it a try!

I’m not going to mention any names, but there’s a town in San Diego County that just did an incredibly stupid thing. Towns do stupid things all the time, of course, but for sheer obliviousness this one really stands out. Some time back a developer with a plan for developing a blighted property in the middle of this town began construction on his community-friendly, mixed-use, LEED-blessed, low carb, high fiber building.

Part of the plan was an underground parking garage that would keep quite a few cars off the street. After he had excavated about 30 feet down he hit ground water. Turns out there’s a perched water table under most of the town and under much of the neighboring town as well. It’s been there forever and has caused problems all over the area ever since people began building things there. Water leaks out of the cliffs and causes them to collapse. Water undermines buildings. Water fills basements. Water deteriorates pavement.

Still, the water, for all the problems it creates, is fresh and clean, as testing proved when the developer first hatched his Bright Idea.

The Bright Idea was to incorporate a cistern into the building and start using the water for flushing toilets, watering the landscaping, and other uses. He figured everybody would win with this approach: he’d have a ready supply of fresh, local, wholesome water for his needs, two communities would have a long-standing problem mitigated at no cost to the taxpayers, and neighboring property owners wouldn’t have to worry about their buildings collapsing into sinkholes. Oh, and the area is under a Level Two Drought Alert with up to 20 percent mandatory conservation, so it’s not like they can’t use the water.

Mr. Developer went to the City with his Bright Idea and they wiped the smile off his face in a hurry. “Sorry,” they said, “there’s no place on our forms for that kind of thing. You’re going to have to forget it. Oh, and you had better figure out someplace to get rid of all that water you’re going to have to pump out of your parking garage.” Long story short, he sucked over 26 acre feet of water out of the ground and spilled it, with the blessing of the City, onto a local beach. He’s still pumping and dumping water today, and will be for the life of the building. In the midst of a drought, with water in short supply, in a community that gets a little over 10 inches of rain in an average year and has had recent annual rainfall as low as under 3 inches, in a community that is suffering with no end in sight, the authorities chose to insist on throwing away water. No doubt there are other city officials in the same building who are working day and night to encourage citizens to conserve water. Go figure.