How much do I water?

I have been a bit late on this blog posting. I am in the University of Arizona Master Gardener Program and the first few weeks kicked my buns! We studied botany in two weeks, information that is normally presented over about three months in a college classroom. The latest course material is more familiar now due to classes that I took through A shout out to Justin Rohner and his incredible program.

The blog was not the only thing ignored for a short time. My garden needs a gentle touch after about a week of neglect.

So I was in the backyard yesterday morning to see what needed my attention and saw sand standing on the surface about 10 feet away from my drip system valves. My heart sank. Just a month ago, I repaired 10 feet of line on the other side of the yard where a gopher munched his way to my artichoke plant.

A week ago, I thought the King Snake that has taken up residence simply created another hole. I am not a fan of snakes but I LOVE my King Snake. I have a gopher problem and he has almost eradicated my gopher population. Not quite, though. The snake only eats about every 21 days and gophers can arrive in between meals. FYI, King Snakes are the most docile snakes you can have so don’t fear them as I once did until I realized what they were.

I filled the “snake” hole with sand because it was in a major traffic area. Yesterday, as I saw the sand rise to the surface in a puddle of water, I knew it wasn’t the snake. In fact, three areas appeared. So the next week for me will be clearing rock and digging down carefully into the three areas to see what is happening. I am sure it is another gopher strike on my plastic tubing that leads to the drip lines.

Screen Shot 2016-08-17 at 3.37.40 PMESSENTIAL TOOLS

This brings me to the purpose of my blog. When you or a landscape designer are installing your water lines, it is imperative that you sketch out your backyard with landmarks and measurements and draw out where your lines are and what valves they belong to. Some of the best drawings include color coding. I didn’t have my designer do this, so as I dig for the problem, I will have to test to see what valve it is. Please learn from my mistake.

Probing-200x300Maybe you don’t have a leak but you wonder how to correctly water your plants, shrubs and trees. The best way is to use a soil probe. It is marked at the 1, 2, and 3-foot level. You can make your own soil probe with rebar and mark it for 1, 2, and 3 feet. As a general rule, 1 foot is the depth for watering plants, 2 feet for shrubs and 3 feet for trees. It’s called the 1-2-3 Rule. Water your garden thoroughly then measure the depth of your soil 2-6 hours afterward, depending upon the quality of your soil. If you are measuring a tree in our native clay soil, let it sit for 4-6 hours then stick in your probe along the canopy of the plant, shrub or tree. We measure at the edge of the canopy of the plant or the edge of its circumference (also called the drip line because on thick vegetation, it is the area that drips the most after rain. It’s also the area to install your drip line.)Screen Shot 2016-08-17 at 2.29.00 PM

If you put your probe in and it only goes one-third the depth you need, you need to multiply the watering time 3 times, one-half the depth = 2 times, etc. The amount of time you water will never change but the frequency will depending upon the climate (temperature, humidity, did it rain, etc.)

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Below is an estimate of watering frequency for the Phoenix area, depending upon times of the year. It is included in the handbook “Landscape Watering by the Numbers,” which is the best guide I have read on the topic for our region. It’s also only 18 pages and free. You can download the pdf or pick up a printed copy at most city Water Conservation offices. The frequency is adjusted depending upon rainfall and unusual weather conditions. It is also slightly different depending upon if your plant, shrub or tree are in shade or direct sunlight (referred to as micro-climates in other blogs). Occasionally check with a probe to make sure your plants are still getting enough water.

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I think I have delayed the inevitable enough. It is time to dig and repair the drip system line.




I am a certified agriscape designer and Maricopa County Master Gardener. I have been gardening since I was six years old and worked in my grandfather's garden. I believe that the only way to be a responsible gardener is to garden organically. It improves our soil, is safer for us to eat, sustainable and it protects our pollinators and soil from chemical poisoning.