Way too late for CGM as a pre-emergence or even synthetic pre-emergence unless you live in Canada with snow still on the ground.

thanks Texas, what about fall application? what recommended for that time (and what time) as far as organic?

I'm not Texas but I'll jump in anyways. Fertilize once in May, June, July, August, September and October. When someone asks how to deal with crabgrass organically, frequently they are told to apply 20 pounds/1000 feet of corn gluten meal. What you should know is that it takes time and numerous applications of the stuff over a number of seasons for it to even approach the effectiveness of readily available synthetics. Quoting my friend dchall_san_antonioÂs frequent advise:
1. Water deeply and infrequently. Deeply means at least an hour in every zone, all at once. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. If your grass looks dry before the month/week is up, water longer next time. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds.

2. Mulch mow at the highest setting on your mower. Most grasses are the most dense when mowed tall. Bermuda, centipede, and bent grasses are the most dense when mowed at the lowest setting on your mower. Dense grass shades out weeds and uses less water when tall. Dense grass feeds the deep roots you're developing in 1 above.
3. Fertilize regularly. I fertilize 4 times per year using organic fertilizer. Which fertilizer you use is much less important than numbers 1 and 2 above.

Bill Hill

Here is a link that might be useful: Organic lawncare FAQ

I'm not in Texas either, but I thought I'd shorten texas-weed's user name!

So, you are recommending 20lbs/1000sq.ft. each month through the summer? In (just) the back yard, that is 200 lbs each month. I was quoted $30 for a 50lb bag at a feed store (product labeled as fertilizer). that is $120 per month, and for 6 months, that is nearly $700. I don't think that will fly. The don't carry soy bean gluten meal. My local Agway sells their own 'organic' brand that is supposed to be CGM, but it is more expensive yet at $30/40lb bag.

Will it be completely worthless/ineffective to put down less than 20lbs per 1000 sq.ft.?

I'm sorry, six times was a bit extreme, four time would be adequate. Quantity per 1000 ft depends on the protein or nitrogen made available. For soy bean meal apply 14 lbs per 1000. that will give you 1# nitrogen per 1000 sq ft. That 20 # per 1000 is the number usually stated for CGM to be effective as a pre-emergent herbicide, and it has to be applied twice and certain irrigation and dry periods are required and the effectiveness takes time perhaps years to build up. I personally would not use CGM. To determine the amount of N actually applied divide the % of protein by 6.25 Soy is about 45% protein and therefore has 7% nitrogen released to plant use. 100 pounds would release 7 lbs nitrogen and therefore would cover 7000sq ft. ThatÂs 14.25 pounds per 1000 sq ft for 1 lb of Nitrogen. This formula works for other grain and feed sources in which you know the percentage of protein. Soy can range in price between 8 and $40 for 50 pounds. Shop around. Purchase in bulk from farm animal feed stores.

Bill Hill

found SBM for $15/50# bag. three bags should cover the back for less than $50. that is nice. Is SBM the dusty stuff that is going to cover me after I spread it?

presumably it is ok to switch, perhaps a CGM for action in early spring for pre-emergent and SBM other times for fertilizing needs and budget ease?

Hey Bill, just curious as to where that 6.25 number comes from in the protein to nitrogen conversion.

$15 is a good price. SBM is not very dusty. CGM is the dusty stuff. IMHO CGM is a waste of money unless you can get it cheap. 10 # per 1000 as a fertilizer, Do some research if you think you want to use CGM as a pre-emergent herbicide. You will need a whole lot of it. Yes, do diversify your lawn foods a little. Alfalfa pellets (rabbit food) is often used. Look at Milorganite as an organic fertilizer too. Available at Lowes or home depot. Skizot - Good question. I don't know where that 6.25 number comes from in the formula. It is commonly used however. I just don't know the biology or physics behind the formula.
Bill Hill

Thanks, Bill. I'll do some google'ing. :-)

>"that is $120 per month, and for 6 months, that is nearly $700"

But, but ... you intend on getting a dog! (real BIG evil grin!)

>But, but ... you intend on getting a dog! (real BIG evil grin!)

yeah, I know the cost of pet ownership. :) but going from a bag of weed and feed at $45 per year, and some lime, well $700 is quite a jump.