Overseeding Tall Fescue

post by MichaelS76 on Sep 15, 2021

I’m going to be aerating and overseeding in the next couple of days. I’m currently running a Flex Daily schedule and have read here that it’s best to create three Fixed schedules to help with the new seed. A few questions:

• I plan to setup schedule to run at 6am, 12pm and a last run at 6pm. Are three schedules a day enough?
• Should I run these three schedules for the first week and then begin to drop off one schedule a week until a total of three weeks has passed?
• Do I disable my current Flex Daily schedule while running these three daily Fixed schedules and then reactivate after the three weeks has passed?
• If I do deactivate my Flex Daily, will I lose all of my current stats associated with this schedule?
• Should I disable all Weather Intelligence settings when setting up these three Fixed Schedules? I’m thinking I should keep the rain skip active, but disable the others; saturation and seasonal skips?
• Any other tips and tricks I should know before creating these schedules?

post by rraisley on Sep 15, 2021

I haven’t overseeded for a while, but I have had new sod placed in two areas, and have been doing something similar to prevent them from drying out.

I used 4 times a day at first, 3 minutes each time, starting at 10am and then every 2-2.5 hours. IMHO, you need to do this during the heat of the day, when things dry out, so don’t believe it’s required as early as 6am or as late as 6pm.

I ran it like this for 2 weeks, then tapered off to 2 times a day, etc.

Again IMHO, no need to disable Flex Daily. I water so about 0.1" of water is applied to the surface for the new grass; Flex Daily then makes up the rest of it. Since I believe a fair amount of the 0.1" of water evaporates, I increase the Crop Coefficient for the zone a bit to be sure Flex Daily applies enough water. Flex Daily works great while using Fixed watering; it just considers it in when to water.

BTW, I wouldn’t do 3 separate schedules, unless you also need to water other areas during that time. Manual Cycle & Soak works great. 12 minutes of total water, Cycle 3 minutes, Soak 1:57.

post by MichaelS76 on Sep 15, 2021

Thank you for the answers to all my questions. I’ll make sure to setup 4 runs a day rather than the 3 I had originally planned.

Regarding the answer above, are you running each zone for 3 min. total regardless of your nozzle types? I have 6 zones; 4 are rotars and 2 are fixed. Should I run all 6 of these zones at the 3 min. you recommended or adjust time based on how much more water the fixed heads put out? Maybe 3 min. for rotars and 2 min. for fixed?

post by tmcgahey on Sep 15, 2021

When I overseed here in Arizona, I run 6 fixed schedules spread out from early morning to just before dusk, and run the zones for 8-10 minutes each, but I have Hunter MP Rotators with a low PR.

Now, when we overseed in Arizona, daytime temps can still be high 80’s, so I probably need to water more often than you to keep the seed damp. Start with 4, if you notice that it is drying out between the intervals, pop another in. There really isn’t a hard science to this, just keep the soil and seeds moist!

post by rraisley on Sep 15, 2021

I used the Nozzle Flow in/h to calculate my times. I also measured my flows, both by catch cups and by measuring GPM and zone area. So I know how long each zone takes to provide, say, 0.10" of water. In my case that’s 18 minutes for the front yard, 9 minutes for the back. I want to apply somewhat less than 0.10" per day, letting Flex Daily make up the rest, so am operating the Front yard for 12 minutes total in 3 minute increments. The back yard started off similar, but is now fixed at 6 minutes total, in 3 minute increments.

FYI, multiple schedules as tmcgahey discusses is more flexible, and has the advantage that other timed or manual irrigation can occur in between, but I like the simplicity of Cycle & Soak schedules.

post by Linn on Sep 17, 2021

I also have fescue, and for overseeding I run morning, noon, and late afternoon fixed schedules. Manual Cycle and soak would work, but I do the 3 different schedules so that all 3 run for one week, the afternoon watering drops off after one week, and the morning one after 2 weeks. Each year I just go in and set the start date and end dates (since the start date changes every year). I’ve been doing this for the last 5 years and it works well for me.

post by MichaelS76 on Sep 17, 2021

Thank you for the input. I set up three separate fixed schedules last night (10am, 1pm and 4pm) with the same idea that you had with the schedules dropping off every week. I think it was a post from you a few years ago that lead me to this idea. I ran my first schedule this morning. I have my rotar zones running for 4 min. and the fixed zones for 2 min. So the new seed is getting 20 min. of water per schedule for a total of 1 hr. a day (for the first week, at least) Hopefully the new fescue seed will be fine with these three schedules and watering times.

post by Jordan2819 on Sep 29, 2024

I’ve always read that you want to transition from keeping the seed moist to watering deeply and infrequently after germination. Once you have germination and you’re dropping off these waterings, are you also increasing the watering times on the ones you keep active?

post by Linn on Oct 7, 2024

No, but mainly because it cools down here and I cut all the water off. I’m in Charlotte, NC, have been doing this for years now, and the new grass has always done well for me.