just a thaught do you hate dandylions ? on the other hand i think you can just spray a weedkiller that doesnt hurt the grass .

i dont think you have to scarify as the weed killer goes in through the leaves

Welcome, Bigweed!
Were you thinking of scarifying after the weeds were gone, to prepare for reseeding? It may not be necessary, depending on what kind of grass you have, and how badly it was damaged by the dandelions. I'd just kill the weeds with a selective spray, like Noseypotter suggests, then feed the grass and see how much comes back. You may only need to do a little spot repair.
Massive quantities of weeds, like that, are usually a symptom of problems with the health of the grass. You might want to review your care practices for the lawn, including feeding, soil maintenance--aeration, organic matter, liming, etc.--wear and tear, and mowing practices. Healthy lawns rarely let more than a few dandelions in. Hope this helps!

Hi Bigweed and welcome to GoY!

There has been warnings in the press of an abundance of dandelions this year. I would use a selective weed killer if necessary and just re-seed the areas larger than a couple of feet across, as needed. Grass will cover any bald spots less than this within 12 months!

here here

Dear All
Thanks very much for your help. I will try and get a friend (with tractor) to spray the area with a selective killer.
Thanks again

your welcome