[macleod52]

So I'm using the lawn log that was supplied in the stickied post and I have a question about the calculations. I did not change any formulas but it seems that my lb/k is high? Per G-man's post in my other thread he said not to go over 1 lb/k per month. It's calculating 3.11 n/k.

For reference this is the product I used. Menards Crabgrass Preventer. I used a 15k bag (51lbs) and a 5k bag (17lb).

 

[g-man]

Did you change the lawn size value at the top of the log? You need to enter your lawn size for it to calculate correctly.

 

[Green]

So I'm using the lawn log that was supplied in the stickied post and I have a question about the calculations. I did not change any formulas but it seems that my lb/k is high? Per G-man's post in my other thread he said not to go over 1 lb/k per month. It's calculating 3.11 n/k.

For reference this is the product I used. Menards Crabgrass Preventer. I used a 15k bag (51lbs) and a 5k bag (17lb).

It's not clear if you already applied, and what you based application rates on (the spreadsheet, the bag label, your experience...).

I'm sure G-man will be along later to address that specific spreadsheet and how it works. But going by the label and my experience with Dimension, I can help you address the application rate issue.

I like to go for the 4-month rate usually, so that would be around 4 lbs/K of product. That way it's wearing off by mid to late August so if I have to seed it's no problem. I just don't deal with lbs of AI per acre unless I really have to. It's not how I think, because I'm not dealing with acres.

If using a product with lots of Nitrogen like the one you're using, I like to split this up into 2-3 smaller applications spaced out over time, say 4-6 weeks apart. It allows more efficient use of the fertilizer.

Anyway, at the 4 lb/K rate, it would take 80 lbs of product over 20K area.

Back to the rate question. Again, I'm not going to interpret your spreadsheet, but I do know that in order to get 3 lbs/K of N on the ground, you would have had to put down 11.5 lbs/K of product...

Obviously you didn't do that...because you used 68 lbs of product over 20K area, right?
That equates to the 3.4 lbs/K rate, which is just under the rate I use, but still a pretty decent rate that will last for a while.

At 3.4 lbs/K of product, you put down just under 1 lb/K of Nitrogen.

 

[macleod52]

Did you change the lawn size value at the top of the log? You need to enter your lawn size for it to calculate correctly.

That was the trick. I probably should have checked what cells the formula was pulling from. Much better now (.88 n/k)

Also, thanks for the explanation Green. I was applying at a rate of 3.4lbs/k. In reality I was probably a little shy of that but I will be reapplying again in about 6-8 weeks (due to a large amount of, what I assume is, crabgrass in the yard).

 

[Green]

Glad you guys sorted it out.

 

[zeus201]

Did you change the lawn size value at the top of the log? You need to enter your lawn size for it to calculate correctly.

That was the trick. I probably should have checked what cells the formula was pulling from. Much better now (.88 n/k)

Also, thanks for the explanation Green. I was applying at a rate of 3.4lbs/k. In reality I was probably a little shy of that but I will be reapplying again in about 6-8 weeks (due to a large amount of, what I assume is, crabgrass in the yard).

Why apply again as there is adequate coverage for at least 3 to 4 month. Anything that does sprout up, Ortho products can handle most of the common weeds plus crabgrass.

 

[Green]

Also, thanks for the explanation Green. I was applying at a rate of 3.4lbs/k. In reality I was probably a little shy of that but I will be reapplying again in about 6-8 weeks (due to a large amount of, what I assume is, crabgrass in the yard).

When you say a large amount of possibly crabgrass in the yard, do you mean that you had it last year?

 

[macleod52]

This is what I am dealing with. In another thread I created someone had said it looks like crabgrass. We took ownership last August and I sprayed weed killer a few times to kill what I could. The first image was taken in July. The next two are a close up of what I was left with in November.






These two are from today. I do have grass so I have hope.

 

[Jconnelly6b]

@macleod52 looks like there is not a lot of grass left, most seems to have been crabgrass as you suspect. Crabgrass is a warm season grass, thus it dies in the fall and drops seeds, and then sprouts in the late spring when the soil warms again. The pre-m you put down will prevent all those seeds from germinating, which is good.

You will have to keep us posted once green up occurs, to see how much the lawn thickens into the bare spots. Since you already put down dimension, you will not be able to seed until fall. I propose focusing on improving soil conditions, keeping weeds controlled throughout summer with spot spraying of weed control, and preparing for an overseed (or if you have the time and desire for it, renovation) in the fall.

Keeping the weeds controlled will be key, as you want to reduce the number of weed seeds that get dropped this year so you can break the cycle. Also soil test and then correct any decencies that may exist.

 

[macleod52]

@Jconnelly6b I will definitely be posting a journal once I start getting active top growth. I over seeded last fall in a few area's to see how that turned out I definitely plan to over seed again this fall. I want to focus right now on getting the nutrients in the soil and establishing a strong turf going into the summer.

I will also be getting a soil test hopefully sooner rather than later.

 

[Green]

From the looks of the lawn right now, you're doing the right thing...but as you mentioned in another thread, it looks like you might be way early with the Dimension (since the grass isn't totally green yet). Have Forsythia bloomed yet? And what are day/night temps like? Soil temps?

Definitely not a bad thing from a pre-emergence standpoint to be early! Will be interesting to see what if anything the Nitrogen does, though, since full green-up is still a ways down the road. You definitely want Spring Nitrogen on newly planted grass...but next Spring, you may want to find a 0-0-7 or 0-0-0 Dimension product instead, and use that for at least the first app in early Spring, since you won't need the Nitrogen as early anymore (due to the grass being more mature).

 

[macleod52]

@Green I honestly don't know where to find the forsythia so that won't help me too much. I've been using a combination of the GDD tracker site as well as the http://www.greencastonline.com/tools/soil-temperature to get a rough idea of when to apply the PreM. I also have used a meat thermometer to test soil temps and there were a few days where parts of the yard that get the most sun were around 50 degrees and then other shaded spots were in the upper 30's. We've been fluctuating between daily temps in the upper 30's to 50's and lows in the upper 20's to low 30's.

This week week into next we're going to average around 50 degrees for a daytime high and average lows around 32 degrees. So soil temps will fluctuate between the 30's to 50's. The main reason I applied so early is just to ensure I get it down early enough. I had planned on doing a second application in May regardless so I figured doing it a little early wouldn't hurt too much. I'm not going to lie. I've been itching for a while now so impatience had something to do with it too. haha I'm going to search around to see if I can find straight up Barricade or Dimension locally. The big box stores don't carry it so I'm going to have to try the garden centers and mom and pop stores.

 

[Green]

Cool. So you guys are about 5 degrees warmer than us the past week or two. I honestly don't think I'll be doing my pre-M until mid April this year, which should be within the "target" or "over" timeframe on the GDD. (I think applying during the start of the "over" phase is ok as long as CG hasn't germinated yet, and unless you have a major weed issue. Particularly with Dimension since it has post-M effects. Someone can correct me if I'm wrong.) Hopefully the Forsythia hold off until then...lol. Of course, I've whittled down my weed pressure over the years. Finally as of last year, the only crabgrass I had was in non-lawn areas. You'll get there...

As far as your plan to apply more in 6 weeks, I'd keep using that same pre-M product with Nitrogen for this year, if you can get more of it. Stick with what you're used to for now. You should only need about half the amount for the next app though...if you're targeting around 5 lbs/K of product total for this Spring...which should be plenty even with a big crabgrass problem. That new grass should be able to make use of a good 2 lbs/K of Nitrogen this Spring. Don't listen to anyone who tells you Fescue doesn't thicken up in the first year or two, or that it can't handle N...it most certainly does and can in the first year or two. As long as you don't mind mowing every couple of days in late May! It should help it thicken up to its potential. The problem with higher rates of Dimension, is you might have trouble overseedng as early as you'd like (say, August). Maybe you can time the 2nd (smaller) app for right when the CG is germinating, using the GDD tracker and soil temps.