# Just bought some DEF, how do I spray it?



## Saint Louisan (Jul 31, 2019)

I like several was pretty surprised to learn that DEF has a use in the lawn care arsenal. Past yesterday's thread I know nothing about it. So in this thread it'd be cool for those in the know to spread the knowledge.

What mix ratio for say....zoysia, Bermuda and fescue. Say like a lite, medium and heavy application rate. When to apply and should a surfactant be used.


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## CarolinaCuttin (Sep 6, 2019)

@Saint Louisan The analysis is 15-0-0, and 9.5 fluid ounces = 0.10 lbs N

The rate of N is really up to you, your turf, and your goals. I wouldn't exceed 0.3 lbs N/M just as a general rule for all foliar sprays. For growing in weak areas in bermuda, 0.25 lbs N/M every week, to add to a bermuda PGR app, 0.15 lbs N/M.

Zoysia isn't going to need as much nitrogen, maybe start with 0.15 lbs N/M and see what that does. Experiment with it, find out what works best for you. No surfactant needed, urea is easily absorbed by the leaf, but if you want to add it in it will probably help to some degree.

The only thing that is special about DEF is that it is pure water and pure urea, no biuret (a common impurity that gets in during urea production that is damaging to turf). Avoiding the biuret and not having to dissolve granules is why I like it.


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## a_chan (May 4, 2020)

CarolinaCuttin said:


> @Saint Louisan The analysis is 15-0-0, and 9.5 fluid ounces = 0.10 lbs N
> 
> The rate of N is really up to you, your turf, and your goals. I wouldn't exceed 0.3 lbs N/M just as a general rule for all foliar sprays. For growing in weak areas in bermuda, 0.25 lbs N/M every week, to add to a bermuda PGR app, 0.15 lbs N/M.
> 
> ...


Is there any concern with shelf life regarding the solution? Wish I knew about the DEF before buying a 50# bag of urea for 1500sqft 

Probably will pick it up after finishing the granule bag.


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## CarolinaCuttin (Sep 6, 2019)

@a_chan For use as DEF, the shelf life is 1 year or 2 years if stored at room temperature away from sunlight. Who knows how long it keeps for fertilizer use. I go through one jug per season even with a small lawn, so I never run into any issues. You have 1100 square feet, so at 0.5 lbs N/M per month (fairly typical nitrogen use for healthy hybrid bermuda) you have about 6.5 months worth. I can't imagine you would waste much if any, and at $12/jug it's not a big deal anyway.


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## mwemaxxowner (May 30, 2020)

I've never priced def. Is this a cost effective way to put out N? I've just put out what should be my last application of granular fertilizer for the year, but it might be something I give a shot next year!

In "N/M", is M short for 1000 ft² ?

I wonder if it would benefit me to spray it on my young shrubs.


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## FedDawg555 (Mar 19, 2020)

CarolinaCuttin said:


> @Saint Louisan The analysis is 15-0-0, and 9.5 fluid ounces = 0.10 lbs N
> 
> The rate of N is really up to you, your turf, and your goals. I wouldn't exceed 0.3 lbs N/M just as a general rule for all foliar sprays. For growing in weak areas in bermuda, 0.25 lbs N/M every week, to add to a bermuda PGR app, 0.15 lbs N/M.
> 
> ...


Are all brands of DEF the same? I don't own a diesel so I have never even picked up a jug to read it. Any brand you recommend that you've sprayed with no issues. Pics would be awesome. I'm mainly looking to supplement with my PGR plus feature iron apps.


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## CarolinaCuttin (Sep 6, 2019)

@FedDawg555 I haven't seen any other mixtures other than 32.5% urea and 67.5% water. All the labels I've read are exactly the same, it is a standardized mixture. I use Blue Sky because that's the cheapest one my local Wal-Mart carries. Used it on both fescue and bermuda and it's been great.


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## LoveMyLawn (Oct 14, 2019)

I hopped on the DEF train a month or so ago. Do what @CarolinaCuttin says with the formula. He's been very helpful on my DEF questions. :thumbup: My goal is 0.50 lb N/M a month with my PGR program. I'm applying 0.25 lbs N/M of DEF every 2 weeks with my other apps. I've been very pleased with it.

Past weekend I saw at a large chain gas station here called Buc-ees, similar to the E. Coast Wawa. They have Super S brand DEF 2 gal for like $6.30. That's a smoking deal.


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## rjw0283 (May 11, 2020)

The bag of Urea I bought is so easy to dissolve, that I probably wouldn't do the DEF option. 50lb bag of urea for 25 bucks or a 15 dollar jug of 2.5 gallons of def. I think it's a preference/yard size thing. It's good to know as bags of Urea aren't as readily available as DEF is. You can run to the gas station and be fertilizing your yard in a few minutes. So it's definitely convenient!


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## CarolinaCuttin (Sep 6, 2019)

Thanks @LoveMyLawn! Glad everything has been going well so far 

@rjw0283 No doubt it's cheaper to dissolve the urea, but most of that stuff is Ag grade and I don't trust the purity. Measuring it out and dissolving it just got to be a hassle especially for me with a small yard.

If you wanted to make a DEF equivalent (NOT TO BE USED IN ENGINES) you could dissolve 7.35 lbs urea in sufficient water to yield a 2.5 gallon solution of 15-0-0.


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## ABC123 (Jul 14, 2017)

Interesting. The local gas station has it for 2.99 at the pump. Would only use about a gallon per application, might come in handy.


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## rjw0283 (May 11, 2020)

ABC123 said:


> Interesting. The local gas station has it for 2.99 at the pump. Would only use about a gallon per application, might come in handy.


Completely off topic but this reminded me of about 2 years ago, a hurricane was coming and all of the gas everywhere was sold out in all octanes EXCEPT ethanol free, I pulled up to the pump and filled up my truck and everyone thought I was going to mess up my vehicle... Hilarious! Hopefully, people don't figure this out. :lol:


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## Saint Louisan (Jul 31, 2019)

Thanks for the responses CarolinaCuttin and thanks to the rest for the questions!

One more question or two if you don't mind... how long should the spray solution dwell on the grass before being rinsed off? Does over night hurt at the lower .15lb rate?

Do those ratio recommendations stay the same when it's being used to compliment FEature or should a lesser amount be added?


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## CarolinaCuttin (Sep 6, 2019)

Saint Louisan said:


> Thanks for the responses CarolinaCuttin and thanks to the rest for the questions!
> 
> One more question or two if you don't mind... how long should the spray solution dwell on the grass before being rinsed off? Does over night hurt at the lower .15lb rate?
> 
> Do those ratio recommendations stay the same when it's being used to compliment FEature or should a lesser amount be added?


You can safely leave the DEF and FEature on the leaf overnight, but you don't have to. For iron and urea, after about 4 hours the grass has absorbed 90-95 percent of what it's going to absorb through the leaf, so at that point you can irrigate. If you just leave it on the leaf, it's generally a good idea to wash it off in 24 hours.


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## Saint Louisan (Jul 31, 2019)

CarolinaCuttin said:


> Saint Louisan said:
> 
> 
> > Thanks for the responses CarolinaCuttin and thanks to the rest for the questions!
> ...


Would you say that this solution is something that shouldn't be applied in direct sun or high temps?

Sorry for the bombardment, this is nifty. I'm contemplating giving it a late night spray to aid in neighbor shaming. Lol


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## CarolinaCuttin (Sep 6, 2019)

@Saint Louisan I've never had a problem with it in the Carolinas. You want to make sure the grass isn't drought stressed before application because it can make it worse, but I've applied 0.25 lbs N/M in the heat of the day no problems. Your results could be different because of different temperature and humidity conditions, but I don't think there is any reason to worry. If you're apprehensive just slowly bump it up every app and look for signs of tip burn.


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## Saint Louisan (Jul 31, 2019)

Well it's been informative! I certainly appreciate you taking the time to share your expertise. If any other questions pop into my head I'll ask them tomorrow.

Thanks


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## LoveMyLawn (Oct 14, 2019)

Saint Louisan said:


> CarolinaCuttin said:
> 
> 
> > Saint Louisan said:
> ...


I'm in the Dallas area. With my schedule I've been spraying DEF on Friday afternoons around 6-7pm in full sun, high temps. Sprinklers go off at 6am Saturday morning. No issues at all. I support the neighbor shaming. :mrgreen:


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## jhealy748 (Jul 25, 2019)

I've always wondered if this would work! Great info!


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## Gilley11 (Nov 3, 2019)

That's all N.....what about the P and the K?


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## PGunn (May 17, 2020)

For struggling zoysia patches would 3 oz DEF per gallon/1000sqft be OK or is that too much N?


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## Saint Louisan (Jul 31, 2019)

A brief after action report:

Yesterday 8am I sprayed the DEF at the .15lb per ksft rate, tank mixed with FEature. Ran the sprinklers at noon to rinse it off.

I'm still not getting the color out of the iton that I expected (I need to play around with ph'ing the water) but I'm amazed at the growth the nitrogen brought on. I'm pretty sure the lawn grew a 1/2" by yesterday evening.

I'm definitely gonna keep spraying my this on the thin spots and see how it fills in.

Is this solution only useful on the grass blades or does it help to soak the bare soil?


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## Gilley11 (Nov 3, 2019)

@Saint Louisan both. Since zoysia pushes rhizomes it could be absorbed there if there are rhizones where you spray. However, soaking the soil will be way overkill.

Guys, your turf also needs P and K, with only doing the N you aren't supplying it all of the nutrients that it needs unless your soil already has those ready to go.


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## LoveMyLawn (Oct 14, 2019)

Gilley11 said:


> @Saint Louisan both. Since zoysia pushes rhizomes it could be absorbed there if there are rhizones where you spray. However, soaking the soil will be way overkill.
> 
> Guys, your turf also needs P and K, with only doing the N you aren't supplying it all of the nutrients that it needs unless your soil already has those ready to go.


In DFW our soils are typically pretty high or good enough with P that not much or any is needed. I'm working on trying to source some SOP. It's not easy to find though.


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## dicko1 (Oct 25, 2019)

This thread has some more info on dilution of DEF

https://thelawnforum.com/viewtopic.php?f=24&t=5097


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## RBall (Mar 16, 2021)

Gilley11 said:


> That's all N.....what about the P and the K?


I am wondering the same thing. How does everyone solve for the P and K if you do straight liquid nitrogen apps from something like DEF, Urea, nExt, etc.


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## Boy_meets_lawn (Sep 27, 2020)

RBall said:


> Gilley11 said:
> 
> 
> > That's all N.....what about the P and the K?
> ...


SOP either granular or sprayed will take care of the K. Some people are high or adequate in P and dont require any as they mulch mow or live in a restricted area where applications are restricted.


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## Kicker (Apr 5, 2018)

Gilley11 said:


> That's all N.....what about the P and the K?


easily amended with other products on an as needed basis per a soil test/analysis.


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