Watering after overseeding help

1058 Views 24 Replies 8 Participants Last post by alexbc, 8 d ago

alexbc

Discussion Starter · 26 d ago

Hi all,

just did a lawn leveling with sand and compost, killed some poa and crabgrass and then overseeded. So need help on correct watering.

I have a sprinkler system with 6 zones. Last time in the fall when I overseeded, used 4 times a day watering for a week and then 3 times for 1 week, Going to 2 times after that. It was overkill I think. Got tons of moss and my germination wasn’t good.

Questions:

How many times a day to water?
How long to water. If my weekly 1inch watering for zone 1 is 30min, should I do 15/10/5min?
What time of the day to water? I’ve been told not to do early morning as we have morning moisture already and not to do evening
Should I vary the watering schedule per weather (more on a hotter day, less on cold)?

Any other tips?

1 - 20 of 25 Posts

secured2k

· #2 · 26 d ago

Check the cool season lawn guide sticky post for some good advice overall, especially on over-seeding and watering in your case.

The answers you see to water x times a day for x amount of time are general guidelines that should be modified for your soil, local temperatures, or other local factors.

Moss - check/correct pH and watering amount.

For new seeding:
How many times to water per day? As many times as needed to MAINTAIN moist soil in the top 1-2 inches. Depends on your soil type and temperatures

How long: As long as it takes to MAINTAIN moist soil in the top 1-2 inches. Depends on your soil type and temperatures and sprinkler system/water flow.

What time of day to water: In the morning right before or at sunrise. Watering during the day causes inefficient use of water due to wind and evaporation. Avoid watering near or after sundown.

Vary watering based on your local weather/environment: Yes.

I suggest getting a moisture probe and tailor your water based on the results of the soil moisture test.

If you are asking for watering steps for established lawns, the general guide is to water about 1 time a week very slowly (low water volume, over a long time) to let the water slowly and evenly seep into the ground. The goal is to get 1” of water in the ground; and you take into account local rain fall in this calculation. Watering deep will encourage roots to chase that water down which will better protect the grass from drought or nutrient deficiency.

See less See more

Reactions: 1

bernstem

· #3 · 26 d ago

As temps rise, you will need to water more often to maintain soil moisture at the seed level. I generally water 3 times per day with an in ground irrigation when seeding into bare soil. More if it is hot. Overseeding into an existing lawn will need less frequent irrigation as there is some remaining grass cover at the shade will reduce evaporation.

alexbc

Discussion Starter · #4 · 26 d ago

Thanks. I know the 1” weekly and I do that on normal days. Just curious curious as rule of thumb how much less watering (but more frequent) is needed compared to regular watering.

nismodrifter

· #5 · 26 d ago

4 times a day
6 mins each zone.
x 3 weeks
then twice a day x 1week
then normal watering schedule.

Reactions: 3

alexbc

Discussion Starter · #6 · 25 d ago

nismodrifter said:
4 times a day
6 mins each zone.
x 3 weeks
then twice a day x 1week
then normal watering schedule.

Thanks. I’ve set it up for:

6am
10:30am
2:00pm
4:30pm

Does that makes sense.

PNW_George

· #7 · 25 d ago (Edited)

2

alexbc said:
Thanks. I’ve set it up for:

6am

10:30am

2:00pm

4:30pm

Does that makes sense.

I just over seeded and top-dressed with sand. In the PNW we have had a cool spring with some rain and keeping the seeds moist has not been a problem. I put seed down April 28th and the seeds have just started to germinate. The cool weather has slowed things but has also brought just the right amount of rain making it easy so far to keep the top layer moist. I assume Vancouver is not too different from Seattle/Tacoma. That will change this weekend with forecasts pushing 90 F and I plan on adding a couple cycles and also expect the germinating seeds will have slightly deeper roots by the end of the week to draw moisture should the top layer of sand dry out.

Irrigation system coverage, sprinkler head overlap, soil type, drainage and other variables are different and I can share what I have been doing but that might not work for you.

First, I find no need to run irrigation at 6 AM. My first cycle has been at 10 AM. That may move up if morning temperatures rise. 6 minutes would be too long, even for my rotors, and way too long for my spray heads. All I worry about is keeping the top half inch of sand/soil moist. The frequency of watering will get the moisture level down anyway. If there is rain, I shut the system off.

I had been running at 10:00, 1:00 and 4:00 but just added a cycle and shortened the gaps to 2 and a half hours. I will probably go to 6 cycles by the hot weather coming this weekend but will skip the 10:00 AM today since we had a little rain last night. I used nothing but sand and the top dries out fast in the sun. Most of my spray stations run 2 minutes depending on the amount of overlap, some of the rotors that cover a large area may run 4 minutes. Watering for longer periods of time doen't make the top layer of my sand any wetter, my process is to add more cycles not longer cycles.

Weather is the main variable I monitor. Cool days are easy, the challenge is when the days get hot which fortunately is rare and doesn't last long for us.

Cloud Azure Sky Gadget Font

Plant Mixture Terrestrial plant Grass Soil

See less See more

Hiresdk

· #8 · 22 d ago

I just overseeded in Puget Sound area too. We can get away with spring seeding here b/c we don't get the prolonged heat here and if we stay on top of our watering and feeding program we can keep new grass alive over the summer. I've been running 3 cycles per day for about 10 minutes each to keep the seed damp (probably a little too long for the temps we had last week) Now that the grass has germinated I'm just watering once in the morning, soil is staying damp all day. With these warmer temps we will have this week I'll probably add a cycle. I just want to make sure I don't dry it out when it is still seedlings.

Reactions: 1

alexbc

Discussion Starter · #9 · 22 d ago

Hiresdk said:
I just overseeded in Puget Sound area too. We can get away with spring seeding here b/c we don't get the prolonged heat here and if we stay on top of our watering and feeding program we can keep new grass alive over the summer. I've been running 3 cycles per day for about 10 minutes each to keep the seed damp (probably a little too long for the temps we had last week) Now that the grass has germinated I'm just watering once in the morning, soil is staying damp all day. With these warmer temps we will have this week I'll probably add a cycle. I just want to make sure I don't dry it out when it is still seedlings.

How long did it take for your seeds to germinate?

I have now seeded exactly a week ago, I've done different seeds. The main lawn is all elite PRG, then sides and back that are shady, have a shad mix of Tall Fescue/Fine Fescue. I have NOT seen ANYTHING germinate yet and it's been a week... should I worry yet?

Reactions: 1

secured2k

· #10 · 22 d ago

I am in Zone 7 and seeds I planted in a pot a few days before your post have germinated after about a week. Fresh seeds I planted indoors germinated in 2-3 days (TTTF and KBG). Strangely 2 (of 12) old seeds of warm season zenith zoysia also germinated in about 6 days (this is very fast).

Seeds will germinate based on temperatures and adequate moisture. They also can't be buried too deep or in a way the sprouts can't get sunlight. Seeds can't be watered too much, or they may lack oxygen (drown), rot, or be affected by fungus (and die).

PRG is the fastest (<1 week) and then TTTF (1-2 weeks). KBG/warm season could normally take weeks to a month. If you aren't seeing sprouts, I would be a little concerned. You can test your seeds with a small number ofd seeds in a plastic zip lock bag and a paper towel. If you moisten the paper towel and place the seeds touching with the towel, and then mostly seal the zip lock bag while indoors, the seeds should germinate in a few days. You will see white roots and green shoots. Around this time some light is needed to encourage growth. However, this is just a test to see if your source seeds are good or bad.

See less See more

Hiresdk

· #11 · 22 d ago

alexbc said:
How long did it take for your seeds to germinate?

I have now seeded exactly a week ago, I've done different seeds. The main lawn is all elite PRG, then sides and back that are shady, have a shad mix of Tall Fescue/Fine Fescue. I have NOT seen ANYTHING germinate yet and it's been a week... should I worry yet?

I planted KBG but I pregerminated in a bucket of water for a week, then planted and it came up in about 7-8 days with our temps in the 50's and 60's. That's another story for another discussion.

My experience with rye in these temps is it will be 6-8 days, but in warmer temps can be seen as soon as 5 or so days with it being damp the whole time and not being burried. I wouldn't be worried about it yet. with our rising temps you should see it soon.

NJlawnguy

· #12 · 22 d ago

Not so of topic but, what type of poa, and how did you kill it?

alexbc

Discussion Starter · #13 · 22 d ago

NJlawnguy said:
Not so of topic but, what type of poa, and how did you kill it?

Roundup. Killed the worst ones with some grass around it (hard to avoid). Then soil on top and seeding. I see how they all turn out.

PNW_George

· #14 · 21 d ago

You put seed down one week after me. I have a blend of Creeping Red and Chewings Fine Fescue. The picture from my reply above was from day 9. There was some germination a couple days earlier but I could only really see it in macro pictures I took.

The early part of May was cool and I would expect slow germination. That is not the case now. Our unusually cool spring has turned to unusually hot.

This is a critical time during establishment when the germinating seeds are vulnerable to drying out. I’m at 5 short irrigation cycles and that seems to be keeping the seed bed damp but not saturated. I can spot spray with a hose if a small area dries out too fast and add a 6th cycle if needed.

Keep an eye on it and don’t let your hard work go to waste. Our weather should return to normal soon. Good luck.

alexbc

Discussion Starter · #15 · 21 d ago

PNW_George said:
You put seed down one week after me. I have a blend of Creeping Red and Chewings Fine Fescue. The picture from my reply above was from day 9. There was some germination a couple days earlier but I could only really see it in macro pictures I took.

The early part of May was cool and I would expect slow germination. That is not the case now. Our unusually cool spring has turned to unusually hot.

This is a critical time during establishment when the germinating seeds are vulnerable to drying out. I’m at 5 short irrigation cycles and that seems to be keeping the seed bed damp but not saturated. I can spot spray with a hose if a small area dries out too fast and add a 6th cycle if needed.

Keep an eye on it and don’t let your hard work go to waste. Our weather should return to normal soon. Good luck.

thanks. I know it’s ridiculous. We went from cold and rainy days to super hot days. I can only program 4 times a day so have to manually do more if needed.

MacLawn

· #16 · 21 d ago

alexbc said:
How long did it take for your seeds to germinate?

I have now seeded exactly a week ago, I've done different seeds. The main lawn is all elite PRG, then sides and back that are shady, have a shad mix of Tall Fescue/Fine Fescue. I have NOT seen ANYTHING germinate yet and it's been a week... should I worry yet?

IIRC a basic run down of seed germination under ideal conditions
Ryes 7-10 days
Blues 10-18
Fescues 18-21

Reactions: 1

alexbc

Discussion Starter · #17 · 21 d ago

MacLawn said:
IIRC a basic run down of seed germination under ideal conditions
Ryes 7-10 days
Blues 10-18
Fescues 18-21

Fescue longer than Blues?

MacLawn

· #18 · 21 d ago

alexbc said:
Fescue longer than Blues?

Going on memory here
So I might have them flipped?
Also germination seems to be slower in my little experience if the soil is saturated wet vs damp.
For example the last new seeding project in my yard the low spot was the last to germinate ????

its all fun and every one has slightly different experiences

alexbc

Discussion Starter · #19 · 21 d ago

Another question. It’s hot now and my existing grass is growing like crazy. I need to mow them sooner than later. Specially since next Thursday I’m going away for a week. When is best to mow? Now, before grass is germinated or closer to when I leave when I assume some have germinated by then.

PS. I’m also might be dealing with residual roundup impact. I sprayed Poa and crabgrass which turned yellow in 24hrs, and then a cpl of days later I leveled and seeded. However, the yellowing continued longer. So it kept killing more for sometime. That might have slowed down seeds in those areas.

PNW_George

· #20 · 20 d ago (Edited)

alexbc said:
Another question. It’s hot now and my existing grass is growing like crazy. I need to mow them sooner than later. Specially since next Thursday I’m going away for a week. When is best to mow? Now, before grass is germinated or closer to when I leave when I assume some have germinated by then.

PS. I’m also might be dealing with residual roundup impact. I sprayed Poa and crabgrass which turned yellow in 24hrs, and then a cpl of days later I leveled and seeded. However, the yellowing continued longer. So it kept killing more for sometime. That might have slowed down seeds in those areas.

If it was just glyphosate and didn’t have other long lasting additives’ you should be OK. Glyphosate only works on growing grass anyway and would not do much more for yellow dying grass.

My overseed has a similar problem. I have some areas with nothing but sand and new seed, others where the existing grass where I didn’t kill off undesirable grass is growing fast with the weather and water. I ended up mowing half my lawn where there is a lot of existing grass yesterday. It comes down to compromise. I don’t want the existing grass to get out of control and I don’t want to stress the germinating seeds.

Grass is resilient. I’ve let my dogs run rampant this time, tearing up as Aussies do; I just don’t sweat it much anymore. Mow if you need to. The new grass will bounce back. I use a reel mower if that makes a difference.

1 - 20 of 25 Posts