Question
I have nut grass in my lawn of St Augustine and Bermuda.  Is there a weed killer I can use that is safe for my lawn and will not kill anything but the nut grass?

Answer
Solarize instead.

Solarization is a no-chemicals way of killing Weeds that are taking over the entire Lawn, including your 2 varieties.  It involves heating the Soil to very high temperatures, with moisture, for a long period of time, to such a point that Weeds burn themselves out.

The soil is sterilized of everything.  Nothing is left.  Weed seeds have croaked.  Beneficial and damaging microflora and microfauna - kaput.  It is extreme.  And it works.  I usually recommend it for Lawns with Nutgrass or other noxious weed that is spreading like a house on fire.

To do this, head over to your garden center or Home Depot and choose your weapons:

(1) a few big bags of aged manure and

(2) several of the biggest, cheapest sheets of clear plastic (found in the painting section) you can find.  They're really cheap and you can use them over and over.

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, 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 mud underground should reach down 2 or 3 feet.

Open up the manure and/or alfalfa meal and sprinkle these all over the muddy lawn.  Water some more.  Thoroughly soak the manure and soil.  Cover the wet plot of grass with clear plastic and seal as best you can, to keep air and heat in, like a greenhouse.

Wait 6 weeks.  Add more moisture if needed.  Keep the weeds going, and heat it as high as it will get.

Then go out and see what's dead.  Hopefully all the weeds will be gone.  You're ready to start over.

The idea is to superheat everything under 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.  They BOOST the power of the solar heat by several times -- this concept was tested and although the explanation is still a theory, the practice seems to work and is being used more and more.

Anything that was growing under the plastic will be history.

Do not till the plot after you solarize; this could bring up deeply buried, viable weed seeds just waiting to germinate.

If you are going to re-seed, instead of putting down a groundcover, you can purchase top grass seed from Seedland on the internet:

www.seedland.com

Montana State University Weed Science posts some advice about solarizing soil on its website:

weeds.montana.edu/urban/solarization.htm

Any questions?

THE LONG ISLAND GARDNER