Easy on the Lime. That soil PH seems way too low to me, are you 100% sure? I've never seed a soil PH that low, that's why I'm asking.

I take that you have a Fescue/Bluegrass lawn, yes?

20 lbs. per 1,000 sq. ft. of 5-10-5 would give you the following:

1 lb N
2 lbs P
1 lb K

That's fine to put down all at once, as 1 lb. of N per 1,000 sq. ft. is the usual amount of Nitrogen applied during one fertilizing. If you could find something that's 10-20-10 then that would cut the amount in half, and you'd only need 130 lbs (15-30-15 would be 87 lbs, and so on).

Thanks all!

Auteck, yep, the soil test says the ph is 4.6 in the "new" area of my lawn that used to be wooded. I assume from oak trees and leaves sitting on it for years.

skizot, so I can apply 20lbs of fertilizer per 1000 Sq ft all at once? That just seems like a lot. How did you calculate the 1 lb N, 2 lbs P, and 1 lb K? Thanks for your help. I am new to this.

skizot, so I can apply 20lbs of fertilizer per 1000 Sq ft all at once? That just seems like a lot. How did you calculate the 1 lb N, 2 lbs P, and 1 lb K? Thanks for your help. I am new to this.

20lbs of that specific fertilizer, yes. It's all about the percentages of N, P, and K in the fertilizer. If the bag is labeled 5-10-5 (N-P-K), then it contains 5% N, 10% P, and 5% K by weight. So, in order to get 1 lb. of N per 1,000 sq. ft., you'd need:

# lbs. N per 1,000 sq. ft. desired / percent N
So, you have:
1 / 0.05 = 20 lbs. of 5-10-5 fertilizer per 1,000 sq. ft. to achieve your 1 lb. N per 1,000 sq. ft.

A 5% N fertilizer is a very weak fertilizer, and will probably cost you more, since you have to apply so much more product. They have 15-15-15 and 20-20-20 fertilizers out there, and you'd probably be better off with one of those. Or, if you could find a 20-40-20, but I haven't seen anything like that.

My 2cents on your ph and amount of line to put down. To increase your ph. 50lbs of lime applied to 1000sq. ft. would raise the ph one point. so if your test are correct at 4.5 then you would need 150lbs of lime per 1000sq. to bring the ph up to 7...

Thanks skizot, so accoring to the formula, if I went with the 20-20-20 (which my local Lowe's sells), I would only need 5lb per 1000 sq. ft to stay at the 1 lb. N per 1000 sq. ft.? Does it matter that the Phosphorus is going to be off?

bwsnc,

Yup, 5lbs. / 1,000 sq. ft. of 20-20-20 would give you the 1 lb. N that you're looking for. I wouldn't worry too much about the Phosphorous not being double. From their suggestion, they want you to put down 2 lbs. per 1,000 sq. ft. Even though you're only getting half of that, I wouldn't worry about it. If you end up getting too much P in the soil, it's not something you can get rid of, and it can affect iron uptake as well.

Ok, went to Lowe's and they were out of the 20-20-20 so I got the Weaver 17-17-17 "Lawn and Plant Food". Question, it didn't say weather the Nitrogren was slow release or not. Should I be concerned with that?

I did an actual calculation on my lawn area (subracted out the house, driverway and other non-lawn areas. The total lawn area of my property is 10,500 sq. ft. So I bought (2) 40lb bags and will apply 60lbs (so about 1 1/2 bags to my entire lawn).

Sound right?

Bryan

Bryan,

Your math is correct. 60 lbs would give you 10.2 lbs N, so divided by 10.5, you're right below 1 lb. / 1,000 sq. ft. (if you apply it at a rate of 5.88 lbs / 1,000 sq. ft. of product, and you could even do 6 lbs / 1,000 sq. ft. to make it easier and still be fine).

I'm guessing that it's mostly all quick-release. Slow-release is better, and it looks like it's getting warmer in your neck of the woods, but you should still be fine. I'd pick a cooler day out of the next week to apply it.

Good luck, and let us know how it goes!

I am new to the forum here...you guys have been EXTREMELY helpful. Thank you.

skizot, yes today was the hotest day of the year so far here in Charlotte...it was in the upper 80's. I actually turned the ac on in the house today for the first time this season.

Ok, last question though...I don't have experience with fast release, is there a time of day to apply? Do you have to water in immediately and thoroughly? I just want to make sure I don't burn the grass. I will make sure to pick a cooler day in the next week or so.

Thanks!

Hey guys! Ok, I applied the 17-17-17 fertilizer at 1lb of N per 1000 sq ft. almost 30 days ago. I was thinking of switching to an organic fetilzer now like Milorganite. Should I apply that now? Should I switch to organic or apply one more round of synthetic before switching to Milorganite? Thanks!

Bryan

Just some general notes...

the 5-10-5 recommendation was to get your soil back up to "optimal." It is not a long term plan. For ongoing growth, grass mostly needs nitrogen. If you use synthetic fertilizers, a decent plan is to use the general turf fertilizer 3 times a year and a balanced fertilizer once a year. If you follow one of the "step" programs, they usually include 1 step that has more of the other nutrients already. If you go with an organic program, Milorganite is between the standard turf fertilizers and balanced fertilizer in terms of nutrients, so it all evens out in the end.

Also, this is about the latest you would want to fertilize a cool season grass in NC. A mild fertilizer like Milorganite would be fine now. What you don't want to do is apply a high nitrogen fertilizer in the heat of summer.

Thanks, Bill! This is a potentially stupid question but if the goal is to apply 1 lb of N per 1000 sq ft, how can a fertilizer like Milorganite (5-2-0) be any milder than a fertilzer that is let say 39-0-0...either way, you are applying 1 lb of N per 1000 sq ft.

So if I apply Milorganite now, when should I apply anything again? Should I wait until August to apply again or should I apply again in July and skip August? I would like to go to a mostly organic program.

Thanks!

The reason the Milorganite is milder is that it's organic so it's released slowly sa the microbes make the nitrogen available to the plants. The 39-0-0 is available all at once (although there are slow release varieties available).