Is it time to water? Use your moisture meter!

While the rest of the country is freezing, California has had unseasonably warm temperatures (low 70s where we are). We also haven't had a good rain for about a month. So, many gardeners are either just turning on their irrigation, or lying awake at night wondering whether it's time to turn it on. I try to resolve the question by measuring soil moisture. I use this approach for shrubs and perennials. Annuals need to be sprayed during the rainy season, trees need deep watering.
I know that experienced gardeners just stick their finger in the soil and know what's going on, but I don't trust myself. Besides, my fingers are short. You can buy moisture meters at garden centers, usually they are in the house plant section. They are easy to use and easy to break. It's best to take along a stick or long screw driver to make a hole to stick the meter in. So, today I explored my front garden.
First a salvia, which was moist enough. I have a good layer of mulch on top of the front garden, so the rains from last month are clearly still doing some good.

Then I started with the native buckwheat, which at first looked a bit dry (left picture). But when I stuck the moisture meter in all the way, it became clear there was enough moisture in the soil (right picture).

So, I'll monitor that area of the garden, because the top 2 inches or so are obviously dried out. Finally, I went to an even sunnier spot in the garden, and found that the area was really dried out. The photo didn't even come out all that well because of the sun.

I went for my watering can and went around, watering each plant for a bit until I'd used up the 2 gallons. In 3 days, I'll test everything again. Or maybe, if I'm lucky, it will actually rain.

Here are some tips for using the moisture meter:
  • Make holes with a stick to avoid breaking the meter.
  • Stick the meter in all the way to make sure the soil is moist.
  • Stay close to the root ball. Your garden clay may still be moist while the nursery mix the plant is in has dried out.
  • Wipe off the meter after each plant for more accurate results.
  • Before you decide to water, ask yourself what that plant expects that time of year. Some plants are fine when they're almost dry in summer, others need water.
  • Listen to the birds and enjoy the smells of your garden while you test (and, maybe, water). It's a great excuse to spend some time outside...


Good info, I never thought to purchase one of these for garden reviews.
After specifying them for clients the past two years, I finally installed an ET controller this past fall. Theoretically, it is making all the correct watering decisions for me, but it is a little freaky not knowing when or if the water came on at any given time. You can actually check the clock to see when the next irrigation cycle is scheduled, but I already forgot how - the dang things are complicated. Sometimes low tech is the way to go.
Town Mouse said…
Not to mention that you miss out on the time to be outside if you install an ET controller ;->
Spermophilus said…
Having your own ET station is pretty technical!

I lost track of cimas

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