Early use of the garden weasel followed by a grass-clipping mulch are keeping the weeds down nicely. The mulch retains water. Anything I were to grow in the narrow spaces between the plants would require watering instead. Zone and geology make a great deal of difference. Gardening in Massachusetts on a sand that was unsorted glacial till gave me little trouble -- except that I mulched for the first time (mulch plus soggy clay in a steamy, Western PA summer would have been a sure recipe for fungal diseases). The Carolina Sandhills are the remains of an ancient beachfront. The sand is nearly pure quartz and the grains are almost all the same size so its quite different from my Massachusetts sand. And the blistering days (I never thought I'd ever utter the phrase "Its not too hot today. Its only 90.), suck the moisture away so rapidly that I water only at the plants' roots. Any weed seeds in the area that I did not mulch yet are not sprouting because it hasn't rained in 3 weeks. My neighbor uses an annual rye grass on his garden over the winter with good results, but he doesn't care if his garden gives him nothing between late October and mid-June since he only grows beans, tomatoes, peppers, eggplant, and cucumbers. :-)

if you have a hybrid type of grass, it can produce seeds but they won't be viable. basically the grass is sterile. abotu the best thing i cna tell you would be to try them. if it works, great, if not then you tried and now know you jsu tneed to go pick up a bag of seed to fill in the sandy areas. while you are at it, add in some organic material to mix with teh sand. if the areas a pure sand, grass really won't make it any better.

Good to read of your work. After trying various methods, I now peel seeds sown on vermiculite in petri dishes kept at 60 F. Seeds that germinate are easy to see & are then transferred into 8 oz plastic glasses, sealed with plastic wrap & go back at 60 F. Seedlings usually appear within 30 days & go to a light table in the same container. I will try to send a photo of a petri dish with a seed germinating---.Hopefully you can see the radicle circled....

Watch them closely, don't overwater or underwater. I planted 10 lemon seeds that were dry for one year, all of them sprouted and after 3 months only 3 of them are still growing, the other 7 did not make it. The probability of growing dry citrus seeds to maturity is very low.