[macleod52]

As the title states I have two questions.

1. How do I interpret the GDD website? There's early and Optimum. I'm applying the Menards PreM that has a slow release fertilizer. Next weekend is looking like the optimal time to apply; however, I will be in the early phase based on the GDD site. Will it hurt anything by going early? Based on the product I'm using would it be beneficial to apply a second application in May or stick with a weed and feed (I'm dealing with a yard full of weeds so I am thinking that this first year to go the weed/feed route to control everything).

2. Next weekend we are going to start getting in to several days with upper 50's temps. I have about 20,000 sq ft and it looks like we're going to get rain Saturday and Sunday. My thoughts are to apply my PreM on Friday and let nature water it in. What are the downsides to this? What happens if we get 1/4" or less on Saturday but then get 1/2" on Sunday? Will that suffice?

 

[zeus201]

From professor at MSU:

"In addition to using soil temperatures and GDDTracker, a good environmental indicator for pre-emergence timing is when forsythia bushes are blooming with their bright yellow flowers."

Optimum is ideal, but it may it not work out the way we like. I was towards the end of optimum, almost late on the GDD model last year, but the local forsythia wasn't blooming. So I waited until it was and then applied my dimension. I'd continue watching the model / forsythia and hope it lines up with rain. Also check the label and see how soon it has to be watered in as there might be some leeway there.

What happens if we get 1/4" or less on Saturday but then get 1/2" on Sunday? Will that suffice?

Unsure......

General consensus is 1/2" of water is needed to water it in. I'm in a different boat as my lawn is nowhere near the size of yours and I hand water mine in afterwards. But if that instance happened to me I'd call it good....

 

[macleod52]

Thanks Zeus. Per the bag it states "Erratic weed control may result if not activated by rainfall or
irrigation within 30 days after application." It's supposed to rain Sat-Mon as of right now (that could always change). My concern would be not getting enough rain or getting too much since I have a swale that fills up with water. I don't want to put it down and have it wash away.

Also, I took some soil temps the other day and I was around 40-50 depending on the area. It's cooled off this week so I'm not too concerned about soil temp but come next weekend I think it'll be the ideal time.

 

[zeus201]

If is not a hassle, you could also hand water or setup a sprinkler and water in the area that gets flooded.

 

[Green]

I had that situation last Spring...

Got some rain, but not enough. Figured my Dimension didn't get watered in sufficiently by the rain even though I planned it that way, so I had to water with sprinklers over 15K. I think it took over a week to finish watering it all in! Ideally, I would have gotten it done sooner, but it wasn't possible. I didn't have any issues with the barrier, thankfully.

 

[macleod52]

If is not a hassle, you could also hand water or setup a sprinkler and water in the area that gets flooded.

It's possible for me to water in the area that floods. The only problem is that the ground is so saturated (heavy clay) that it doesn't take too much water to flood it at this point. Irrigating will probably not cause the water to run rather it should puddle so it may not be too much of an issue. My only fear would be when the rains come next weekend though that it will wash out the fertilizer.

I'll wait until closer to next week to see what the weather is going to do. I may have to fertilize early in the week and water in the problem area's and let mother nature do the rest.

 

[GrassDaddy]

If your lawn floods easily, wait till after the rain to apply and then water it yourself so you can prevent it from washing the pre-em away. But otherwise your plan looks good. IMO it's better to be early than late.

If you really want to look into it though grab your meat thermometer and go check the temp of the soil, if it's 50 degrees you're good to go - if not then I'd wait a bit.

 

[macleod52]

If your lawn floods easily, wait till after the rain to apply and then water it yourself so you can prevent it from washing the pre-em away. But otherwise your plan looks good. IMO it's better to be early than late.

If you really want to look into it though grab your meat thermometer and go check the temp of the soil, if it's 50 degrees you're good to go - if not then I'd wait a bit.

Thanks Grass Daddy. I tested the soil temps last week and some areas were 50 but others were upper 30's to lower 40's. But we had a cold spell this week so I figured I was still good. It looks like next Thursday is when we're going to start being consistently in the 50's so I think next week will be optimal. I may put it down this weekend since most of the week will be in the 40's. But that should give me plenty of time to get it down and water it in.