Roger505, The great thing about Dimension is it will kill crabgrass post emergently up to five leaves, before it tillers. So, this gives you a larger margin of error when applying Dimension. That being said, if you keeps you up at night then go ahead and apply the Dimension it's not going to hurt anything. Preemergent timing, along with everything else involved in the care of your lawn, is going to have a learning curve. Use your meat thermometer and measure your soil temp at the same time everyday for three days and record the average temp. Apply your preemergent, then if you get some early crabgrass say in middle to end of April, then you know you applied your preemergent to late and next year you can apply at a lower soil temp. Also, it would not hurt to invest in the herbicide Acclaim herbicide, just in case you make any mistakes with your preemergent application. Acclaim is expensive, but it will last you years. As far as your fertilizer app. goes, I would hold on to the fertilizer that you just purchased and use it in the fall, if your soil test indicates that all the nutrients in the bag are not in the excessive range. Also, just for your edification that bag of "slow release fertilizer" is only around 30% slow release. So if you apply 1 pound of nitrogen per thousand square feet then .7 of a pound of nitrogen will be quickly available to the plant. This is ok in the fall, but in the spring you will be mowing your yard twice a week to keep up. A better option would be .25 to .5 pounds per thousand of ammonium sulfate or urea now. Then when you get your soil test back follow their recommendations plus add .75 to 1 pound of N per thousand that is at least 70% slow release. Henbit usually takes a couple of apps to kill, and herbicides take a little longer to work in the early spring because of the cooler temps.

Remember too, as the pre-emergent will do as its supposed to, will prevent grass seed germinating. So if you have plans to overseed this spring, you cant put down pre-emerg. To put it down as directed above, you will have to wait until its effectiveness is lost. Maybe not until fall. The pre-emerg seems to be the only treatment for this so I guess you only have one choice---delay overseeding. The foxtail is like other weeds, it can be knocked down by letting the grass grow higher---shading out the seeds. Increased schedule of fertilizing will help improve the lushness to provide strong growth.

The plan was to use one or more applications of round-up as necessary on two portions of existing lawn then add shrubs. I meant not to apply any fertilizer or herbicide to these portions of the lawn but out of habit forgot. The link below is to the exact herbicide I applied. If the instructions where clear to me I wouldn't have to ask here :) After applying I know I can't overseed, and I know it is safe on established plants, but it is unclear if it is safe with transplanted bushes. As mentioned, the new bushes would be 24"+ for lilacs and 48"+ for arborvitae. After the grass died off, I was going to amend the soil with 4 inches of matured compost to a depth of 12" and width of 60", tilling (or hand turning) in the dead grass with it. My county provides free compost from the leaf and yard waste clippings they collect. I planned to do this per research from several academic sites recommending amending, e.g. http://www.gardening.cornell.edu/factsheets/orgmatter/index.html#compost . Seems I'll have to look into this part more. Here is a link that might be useful: Fertilizer with 0.013% Dimension

I believe Corn Gluten is considered an organic pre-emergence. Emergence meaning when the plant from seed can be seen above ground. Specifically what Corn Gluten does is attack the plant's rectal when the seed coat softens, opens and the stored energy within the seed begins growth by bringing the rectal into its escape route into your soil. Corn Gluten carries with it a low level organic nitrogen percentage that nurtures the existing plants while serving as a pre-emergence product. The cost of this and several chemical ways to do pre-emergence has always been debated. My opinion is that all ways of using pre-emergence tactics is only a relatively short time period of less that excellent control anyway. The chemical companies have always paid the universities to come up with warped facts to satisfy the use of their poisons. For instance as stated above: half life is a relatively short period of time but soil life comes out to be about a year. Few stop to read, think and question. First these chemicals are non-degradable. Half life I guess means only half of it has been flushed by rain or watering from your use point and is on its way to your rivers, bays and oceans. Full life must mean your soil is again void of the chemical. That is a direct statement that everything you put on is now en-route to the oceans of the world. The enormous poison pits and zones in the oceans are known and growing. There is no other place for them to go except to enter the evaporation facts and become even stronger where they are. Severe weather may lift them and redeposit them to complete the journey once again back to the ocean pits. If you use and love sea salt now how do you feel it will be enjoyed in another million years? Back to our soils now stated to be full life with no measurable poison in the soil. What they do not test and will not tell you is how long your natural biological recovery will take. The realistic recovery may be five years or longer. Is there a point of no return? I do not think anyone knows. No part of the answer to that question is very nice. Would growing the grass at four inches and mulching the cuttings make better sense? Would spot treatment in the early recovery make more sense than wholesale broadcast of some poison? Do we really need golf course picture perfect homestead grasses? Could we as homeowners recycle those leaves and plant tops by mulching open soil? Could legumes become cover crops that rejuvenate? I'm sure most could do some of these things to eliminate the use of some if not all man made chemicals. This reasoning and these questions apply to all man made non-biodegradable poison chemicals. All! There are no other statements possible that are absolutely true. How does all this relate to pre-emergence chemical concerns? Dumb question. 90% or more of those chemicals are non biodegradable.