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.

Terps: I think that you may be crediting crabgrass with being a thinking creature, which it is not. Or you may be thinking that Pre-M "prevents" germination, which it does not - even though the name is "pre-emergent". Crabgrass seeds germinate when there is adequate moisture (think April showers) and proper soil temperatures. The Pre-M does not "delay" the germination, and the crabgrass seeds can't really "outlast" the Pre-M's effectiveness. The Pre-M works by preventing root formation after the grass has actually germinated. With no root system, it wilts and dies before you even see it. No second chances, no waiting for the Pre-M to lose it's effectiveness. It's germinated and dead. The only crabgrass that makes it is if the conditions for germination don't happen before the Pre-M barrier breaks down. If you want to bet that we might not get 60 degrees and wet weather before 90 days from now, than put down more at the beginning of Summer. I'm saving my money to use the additional Pre-M in very late Summer to prevent the Poa Annua germination period (which will overwinter and be NEXT Spring's headache).

Definitely not to argue with kimmsr but since steer manure is sold in the spring it seems appropriate to apply it at this time. And steer manure is 'organic matter' so it should help nicely with soil conditioning, especially if the plot is mulched to prevent serious rainwater leaching. Some nice compost would compliment the mix too. As kimmsr says, it depends on the soil's present condition. Good growing.

Crabgrass is a summer annual plant that only returns by seed the following spring. It has a quick-germinating seed, so if you try to establish grass in the spring, the first seedlings you see will almost always be crabgrass. Then if you think the new crabgrass sprouts are your target grass seed coming up, there is a tendency to stop the daily watering. Once you do that the target grass seed just sits there while the crabgrass fills in. It is adapted to heat, low mowing, and dry spells. It's also yellow and shaggy compared to more popular turf grasses. The best way to avoid getting crabgrass is to create a dense turf to begin with. The best way to do that is to make it dense in the fall after the crabgrass has stopped germinating seed. You can kill it out to create open space, seed into the open space, and the new grass will provide that density that keeps the spring weeds out. If you start early in the fall (in northern Utah that means August), then you will have time for the new seed to come in and still reseed if it was not dense enough. Continuing with the best way to keep crabgrass out, if you can withhold water in the spring and keep to a temperature driven watering schedule, that will deprive the summer annual weed seeds from the continual moisture they need to germinate. And the last thing you need is to provide as much shade on the ground as possible. Do that by mowing the grass at the mower's highest setting. Beyond those cultural practices you can use preemergent herbicide as has been discussed. Ideally you will develop a turf that is dense enough that you won't get crabgrass. I have not had crabgrass in forever with a dense St Augustine lawn. Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall.