Question
heavy crabgrass,possibly nutgrass too in grams lawn.in central nj, fullsun. sure no 1 has tended to lawn except to mow. any help, bayer/weed b gone products must b careful on hot day, no wind,cut 1-2days prior & no cut 1-2 day etc. exspensive .   any any help

Answer
Karen dear in Central nj, when someone starts talking about Weed B Gone I see red flags all over the place. Weed B Gone is AWFUL. And COMPLETELY UNNECESSARY!

Let me tell you what I would do with this crabgrass lawn.

I would start over.

And that, Karen, is a very easy thing to do.

There is a foolproof system called "solarization" that wipes out every growing green plant underneath, along with all plant germs, fungus and other pathogens (i.e., things that cause disease including insects and grub eggs and larvae).  It's cheap, and nobody gets hurt in the process including the birds and the bees.

Go down to Home Depot and pick up your equipment: (1) several large bags of aged manure and (2) several of their biggest, cheapest sheets of clear plastic (found in the painting section).  If you know a chicken farm somewhere in the area, get some chicken manure.  Alfalfa meal is available at farm equipment suppliers and is worth its weight in gold.

When you get home, or wherever this plot of weedy land is, mow down all the weeds, as close to the ground as you can get, and have the plot tilled.  Next, water the plot.  Soak it.  You should be able to go swimming in this plot - the soil underground should be totally wet to a depth of 2-3 feet.

Now, open the bags of manure and/or alfalfa meal and sprinkle them evenly all over your plot of land. Water again and thoroughly soak the manure.

Finally, cover the plot with clear plastic and mulch.  Treat the whole plot - the larger this treated area, the more effective and long lasting it will be.

Wait 6 weeks or, if you are really feeling ambitious, the entire winter.  In the spring (or in six weeks), remove the plastic and till.  You are ready to sow or sod a new lawn.

The concept here, Karen, is to superheat everything underneath the plastic.  The moisture generates growth and germination of all the weed seeds that are in there and that would protect themselves by remaining dormant if they were dry.  The high-Nitrogen manure and alfalfa produce toxins that concentrate under the plastic and boost the power of the solar heat by several times - this concept was tested and although the explanation is still a theory, the practice worked and is now standard. Everything growing under the plastic will be history.  In the spring, you will be ready to spread lime, and sow on first rate soil with new grass seed.  Do not till the plot after you solarize; this could bring up deeply buried, viable weed seeds just waiting to germinate.  You can purchase top grass seed from Seedland on the internet (www.seedland.com), I recommend you pick up their Bluegrass since you have the full sun, blank slate and enthusiasm to grow it well.  Best looking lawn in the Garden State.

You can read one California farmer's experience with Soil Solarization (news.ucanr.org/newsstorymain.cfm?story=699) or the Montana State University Weed Science tip sheet on solarizing soil (weeds.montana.edu/urban/solarization.htm).

DO NOT USE CHEMICALS!

Why?

They turn your plot into a chemical waste dump with ZERO beneficial organisms and ZERO natural balance; disease runs rampant and next thing you know you'll be out buying Weed And Feed (which REALLY wipes all signs of life off the map of the earth in your part of the state) and wondering why there are no birds and no butterflies in the trees, and what is that funny pain in my side...

You know how they used to have that saying: "Speed Kills"?

Well, they have improved it.  The new, improved saying is: "Weed And Feed Kills".  

Solarize, my friend.  Solarize.