110% to 0% in three days?


#1

I have been using a Flex daily schedule for a few weeks now. The schedule was updating nicely since we have been getting inches of rain in the last week or so.

However, last night I checked the schedule and it said it was going to run today, even though we got over 4 inches of rain just a few days ago. Upon checking my moisture graph, I see that it shows that the levels went from 110% to 0% in three days time. This doesn’t seem accurate given how much rain we had. There are parts of my lawn that are still too wet to mow, so I know they definitely should not be watered. Even if i alter the available water to the max .20, it still wants to water.

Is there something else I should be changing to be able to rely on the flex daily?


#2

Hey @CH-Johnson,

Your depth of water is pretty low (0.33 in) for this zone. Do you mind posting this zone’s settings?


#3


#4

Your 40% allowed depletion setting is making you water more frequently than if you were using the default of 50%. You might also consider a deeper root setting depending on the type and maturity of your lawn.


#5

I was under the impression that the depletion was the opposite. So you’re telling me that a lower depletion will water more frequently?

It is hybrid Bermuda that is about 3 years old. The only reason I’m reluctant to go deeper with the roots is because when I aerated I noticed that the roots did not seem deep. Not even 5 inches.


#6

The default is 50, which means water when 50% of the water has been depleted.

By setting it to 40, I think the means water when 40% of the water has been depleted, which will be more frequently than the default 50 setting.


#7

I have tifway bermuda, I think you are ok to go deeper on the depth for a 3 yo lawn. If you’re nervous, just knock it down an inch and observe. I do not have clay soil though so I’m not famliar with how that impacts root depth growth.

For allowed depletion, @azdavidr was right. Think of what the term is saying, how much are you wanting to allow your lawn to be depleted of water. If you want your soil to be super dry, then you’ll want your allowed depletion to be higher (i.e. 75%). So when you are at 40%, you are saying you want your grass to be less depleted of water then the default 50%.


#8

@Modawg2k Is correct yet again. The allowed depletion percentage is the minimal amount of moisture loss you want to allow the zones to reach. If you set it to 10%, this means that once the zone is 10% empty (90% full), the schedule will water.

Therefore, bumping it from 40% to 50% allowed depletion will cause the schedule to water less often, but for a longer duration when it does water.

Your root depth is probably fine but you could change it if you believe its not correct. You could always measure it yourself if you want to get your hands dirty!


#9

I apologize because I’m starting to become a broken record, but the saturation level of 110% is just not working for me when I get rain day after day. My moisture levels will look like it needs to water and I will still sometimes have standing water on my soil. What I have been doing in these conditions is to go in one or two days each day after it rains and set each zone to FILL. (Other than this little quirk, I really love Flex daily and just let it run).


#10

I’ve had to do this as well. After a day of more than 4" of rain the depletion went down in half. I filled it up because I couldn’t even walk on the lawn without it being muddy.


#11

Here’s a link on what I found for Bermuda root depth, which is recommended up to 10" in our area. If you do make a change, I would do it an inch or two and wait a while to give the toys time to stretch, then adjust again. You lawn might be capable of deeper watering but hadn’t been watered accordingly.


#12

I think the problem is that after a very heavy rain, the soil is over saturated, if excess water is puddling and not running off, if the soil below the root zone is also saturated. It is probably taking a few days for the moisture level to get back to what it would be normally after a deep watering.

A suggestion is to manually update the moisture level for zones that are over saturated to keep them at full until they are no longer saturated.