View Full Version : What SCU is safe for August?

07-07-2003, 10:26 AM
Ok I know that a SCU of 40% or 50% is best in the hot weather but what is the lowest a guy might go without causing burning or other problems?

I have some 28-3-10 w 2% S and 1%Fe the total N is 1.20 ammoniacal nitrogen and 26.8% urea nitrogen. 5.6% slowly available from SCU which gives it aprox 20% SCU. Is that too low for cool season turf in warm weather.

I am generally looking at non irrigated KY blue/red fescue/rye mix. Temps can get to the 90's and rainfall can be as high as 3 inches in a month or as low as a trace.

I have good luck with this product in the late spring but wonder if it is too hot for the summer ap?
BTW I apply at aprox 3.5 lbs per 1000K in late spring but am thinking about going to 3/4 rate.

What are your thoughts? I am asking because I have some product from earlier this year and it is similar in makeup to my usual summer ap except for the SCU. I usually apply a 29-5-10 with 40%SCU.
Jim-- any help???? I'm always trying to learn.


07-07-2003, 05:48 PM
Something 50% slow release and contains Iron is pretty good I have found.

Some lawns get fert with no "P"

07-08-2003, 03:40 PM
I would think 2lbs per 1000 of 28-3-10 with 5.6% slowly available would work. I believe you only want to slightly stimulate the turf at this time!

What is your basic fert program? e mail me for more input!

07-08-2003, 03:45 PM
I've had good luck with Lesco 24-5-11 40% SCU & 6% Fe on warm season turf (zoyzia, bermuda) with 5 applications, May through Sept. 1 bag/~10,000 sq ft. My chart shows that Kentucky Bluegrass, tall fescue and rye N requirements are in the same range as zoyzia and bermuda.

07-08-2003, 04:28 PM
what would you guys use on st Augustine with a surplus of K
and P and lacking in N. PH is neutral.air temp in the 90's.


07-08-2003, 08:57 PM
Just a thought, maybe if those non-irrigated lawns are gonna fry- let 'em!
Wait 'till Fall brings rains and cooler temps- aerate and fert then...
If the grass is gonna fry anyway why waste the fert?

07-08-2003, 09:28 PM
If you definitely need to get an application down in August and want to use that product up (instead of waiting until fall) I would go at the 2 lb / 1000 sqft rate, like timturf suggested.

If your cash flow permits, pick up some 50-60% SCU product with iron, apply 3/4 lb actual N, and save what you have on hand for fall.

07-10-2003, 11:53 AM
would it be ok to put out ammonia nitrate 34%scu on st Augustine in zone 8b?air temp is around 90+

07-10-2003, 12:18 PM
another question....i have the cheapo scotts speedy green 3000
what setting would i use for the above mentioned fertilizer?

all this is for my own yard not a clients.im in the process of researching into getting my fert license.but as of right now i dont have one.

i used the rapitest soil test kit from lowes to test the soil.
is this accurate enough?

any positive info is appreciated
thank you

07-10-2003, 12:51 PM
ok 1 more question then i'll stop:
is it safe to use atrazine on centipede.i have areas of my yard that are a mix of st Augustine and centipede.i believe atrazine is the preferred herbicide for pre and post-emergant control of dollar-weed.correct?

07-10-2003, 05:17 PM
help me timturf or LGF...please.

"it may not be a rocket science...but it is a science":D :blob1: :blob3: :blob4:

07-10-2003, 07:38 PM
cool season turf, bermunda, and zosia experience only

generally can apply 1lbs per 1000 of quickly available n if water in on cool season turf, but why that much in summer? would assume ok for ceniped, BUT HAVE NO EXPERIENCE

Get a soil test from a lab, look at base saturations 8 to 12 per sample

hope that helps

07-10-2003, 08:06 PM
thank you tim.
I'm trying to soak in as much information as possable before even
thinking of applying fertilizer.Ive seen my neighbors destroy they're yards.i don't want to make any of those mistakes.
the reason I am fertilizing is because I'm trying to get my
turf to spread.its st Augustine in a fairly shaded yard.i water 20 Min's a zone every other morning at 3gph.
i sodded last spring and after this winter\springs fertilizing I'm starting to notice a decline in growth speed as well as less runners.it seems to be dying back a little.
i tested the soil with one of those rapitest brand test kits from lowes.it uses a color comparison not and actual values.not that i would know what proper values would be for N,K and P.
according to the test i had a surplus of P and was fine on K as well.it did show that the N was depleted.
i applied a 34-0-0 ammonia nitrate fertilizer.34%scu according to the salesman at the feed store.i applied at an "approximate rate" of 1lb per 1000sq.
as you can tell i know practically nothing about fertilizers.but I'm spending up to 5 hours a night on the computer reading everything i can.
i sure hope I'm doing the right thing.

07-10-2003, 08:25 PM
heres a pic

07-10-2003, 09:16 PM
lets try this again

07-10-2003, 09:36 PM
hopefully bigger this time..bear with me

07-10-2003, 09:45 PM
this was completly overgrown when i started 3 yrs ago.
there were 15' shortpines and bay trees and thick underbrush.

07-11-2003, 01:24 AM

34-0-0 on St. Augustine in July is a NO NO. If you apply it to heavy it will burn in a New York Second. 34-0-0 is a fast release or total release the second you put it on. For years I grew hay in Baton Rouge, La. and I used 34-0-0. I could get 50 bales an acre every 30 days with 34-0-0. I also got some real brown grass after I applied it, if it didn't rain hard. If soil test say you lack only Nitrogen then go with a 28-3-4 SCU or a 32-2-3 from Scott's or some other home owner type manufacture.

The key here is to use as much slow release as you can. All turf experts will tell you fertilize light and offend. Slow release is the economical way of doing that.

34-0-0, 46-0-0, & 21-0-0 are sprayable forms of Nitrogen that should be tank mixed with other element. Yes they can be spread dry, but you need to be careful they are total release.