I live just south of Fort Worth. Does the Vinegar solution work on weeds for spot-treating during the winter?

Real vinegar, made from grain alcohol, in 10% or 100 grain concentration, is the proper vinegar to use for killing weeds. It is sprayed straight with no water dilution. For a more powerful product, add 1-2 oz. of orange oil and 1 teaspoon of liquid soap per gallon of vinegar. I use the Bio Wash product as the soap. Vinegar is a non-selective herbicide and especially effective on weeds in cracks and in gravel areas. It will kill broadleaf plants and grasses. If the mix is used, keep it shaken during the spraying. The Ozark White Pickling Vinegar is excellent for making your own mix.

I have a vinegar mix I bought at Calloways in the Organic section. Will it work in the Winter?

Yes but you may need to spray it a couple of times. Works much faster when weather is warmer.