Best time of day to water?

I’m using flex daily end by sunrise (since the app recommended) and the schedule is ending by like 330 in the morning and sunrise is about 530. I’ve always read you don’t want water in the middle of the night because the grass stays wet for too long. Is this timing ok? What do people think is the best time to water? I’m allowed to water any time outside of 10 am to 5 pm.

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I have heard the same thing from the company who installed our irrigation system, that if you water too early before sunrise, it can promote mold spores, which damage the vegetation.

So I expected the schedule to start as late as possible, ending before sunrise. However, it seems to start at a fixed time, and if not all zones are being watered, it ends much before sunrise. In my case the last couple of days started 1:44 am and ended 2:15 am, which doesn’t seem like a good idea due to mold.

It would seem that this feature is not quite programmed correctly yet?

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That was my expectation too but I think you’re right. Determining the max run time of all zones run and that sets the start time. Fewer zones run and starts at the same time. Just set my end time to be the beginning of the water ban time so at least it will early morning instead of middle of the night.


I just installed my Rachio today and set up the daily smart flex, and I was very disappointed when I saw the watering was going to start around midnight on some days and only run for a couple of hours. It’s almost like it has a fixed start time for the worst case scenario. In other words, if it needs to run all zones, it needs start by 12:15am so it can finish by 5… so everything starts at 12:15 even if it only needs to run one zone.

What is the recommendation to resolve this?

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Unfortunately it seems to be a feature as of now. For now i’ve set up a later start time.

Hopefy the Rachio folks will fix this soon. Any input, @franz ?

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I’ve got Rachio 3 recently and still learning its features. I have 5 grass zones with similar watering duration (1-2 hours) and frequency (once a week), so I’ve tried including them in a single Daily Flex schedule. No watering restrictions, finish before sunrise. My expectation was that in most cases 1-2 zones would be active in one day, so the watering can start around 3am and finish around 5:40am, and in rare cases it may start before midnight to accommodate all zones. However, the resulting schedule always starts at the same time around 8-9pm, even though most of the time only 1 or 2 zones need to be watered. Doing this every week would promote fungus growth, so I don’t think I can use such schedule. Any ideas how to resolve this? Is there a way to dynamically calculate the start time every day depending on what zones are scheduled?