Hi and sorry to hear you've got grass burr troubles.
We are still fighting them, too -- but we are definitely winning the war. Now we only have a few small patches at the front of the yard where it meet the street, instead of all through the yard. Yay!
We have been 100% organic in this house & yard for almost 3 years now. Previous owner was 100% chemicals.
Our poor yard was FULL of grass burrs. Front and back. Last year, I don't remember seeing any in the back yard.
Once we started watering properly, applying CGM and molasses, and giving the yard some Garrett Juice now and then, we began seeing wonderful improvement.
I looked for a link for you (from the library on this site) about why proper watering is also an important factor in controlling weeds, including grass burrs. No success finding what I wanted (sorry), but basically watering deeply but infrequently allows the lawn to grow deep roots, but kills off shallow-rooted weeds since the upper layer of the lawn is allowed to dry out between waterings.
Back to your question: since Howard said the timing for CGM may be tricky this year (because of a potentially early spring, I'm guessing), if it were me, I would just apply molasses, get on a proper watering schedule (if you're not already) and save the CGM for summer application. Also, if you can afford it, you can put a 1/4" layer of compost or humate on your lawn.
As you will see here:
http://www.dirtdoctor.com/organic/garde ... on/id/300/, anything you do to improve the overall organic health of the soil will tip the scales in your favor, instead of the grass burrs.
Also, if you have time and inclination, pull them, or dig them out by hand before you mow, so the stickers don't go down into the lawn and re-seed. It's kind of a pain, but we've had good success with it.
Happy gardening!
_________________
God speed!
Cara
**
Take time to stop and smell the flowers!
(or... as my ladybug refrigerator magnet says
"take time to stop and
eat the flowers!"
)